Cardiology free book TABLE OF CONTENTS ( Click on the title of each chapter to see the selected chapter)

cardiology book online

Cardiology free e-book online 

TABLE OF CONTENTS ( Click on the title of each chapter to see the selected chapter)

The Electrocardiogram -ECG (adult and pediatric)

Assessment of left ventricular systolic and diastolic function with echocardiography

Arterial hypertension-hypertensive crisis-hypertension in pregnancy

Coronary artery disease stable and unstable-Cases and Notes

Congestive heart failure diagnosis and treatment and a case of heart failure (video)

The Cardiomyopathies

Pericarditis -pericardial effusion

Constrictive pericarditis: Pathophysiology, diagnosis, echocardiography and treatment

Aortic stenosis -A case of stenosis of the aortic valve

Aortic regurgitation (AR)

Mitral regurgitation. Diagnosis, echocardiography and management. / A clinical case (VIDEO)

Mitral stenosis

Tricuspid regurgitation

Stenosis of the right cardiac valves: Pulmonic stenosis, Tricuspid Stenosis

Prosthetic heart valves

Infective Endocarditis ( Diagnosis, treatment and a case)

Tachyarrhythmias-supraventricular and ventricular tachycardia

Bradycardia-Bradyarrhythias. Diagnosis,treatment and clinical cases

Pulmonary Hypertension and pulmonary arterial hypertension

Congenital heart disease. A concise introduction (overview)

Atrial septal defects (ASDs) and ventricular septal defects (VSDs)


My free emergency medicine book online: Emergency Medicine and First Aid. A free ebook online.

A useful link for a free Cardiology journal  (Continuing Cardiology Education, a journal with review articles):

A Useful and interesting website about Cardiovascular Research
Cardiovascular Research Institute

A useful link for drug information : emc

These are sites that contain easy-to-use medical calculators, to calculate for example body surface area (BSA), body mass index (BMI), estimated glomerular filtration rate (eGFR), CHA₂DS₂-VASc Score for Atrial Fibrillation Stroke Risk, 
 10 -year cardiovascular risk scores,TIMI and GRACE risk scores for acute coronary syndromes, Duke criteria for infective endocarditis, Cardiac index and systemic vascular resistance calculators, Calorie calculators/ Drug dosage calculators, etc


Online Medical Calculators-Medicine World org

Medscape-Medical Calculators for medical professionals

LINKS TO OTHER FREE SOURCES OF MEDICAL INFORMATION  (About Cardiology, emergency medicine, internal medicine, and other clinical fields)

Cardiology cases-videos by Dr Chatziathanasiou  
(This is my own channel ! It contains cardiology cases. It is under development -more videos are being continuously added).

Clinical Advisor - Decision Support in Medicine

The Merck Manual - MSD Manual Professional Edition-Cardiovascular Disease

Radcliffe Cardiology - Information for Cardiology Professionals

NICE Evidence search: Cardiology

Continuing Cardiology Education, a journal with review articles):


E medicine-Medscape-Cardiology

The Echo-Journal-Echocardiography videos and Tutorials

123 sonography you tube channel (by Professor of Cardiology and echocardiography Thomas Binder) Link

ECG Library-Life in the fast lane medical blog

Dr. Smith's ECG blog

Cardioserv blog-Echocardiography

CCC Live Cases (Interventional cardiology cases and videos)

Cardiology News  (site for physicians about cardiology news and new developments in cardiovascular medicine)

European cardiology review (ECR)  This is a free journal, but to view all contents you need to register online to the webpage (Registration is free -Takes about 5 minutes)

Prof N Kumar Cardiology lectures (videos about interventional cardiology -electrophysiology-ECG etc)

DeBakey Institute For Cardiovascular Education and Training-videos-cardiology lectures

UofL Internal Medicine Lecture Series-cardiology lectures (videos)

Dr. John M ( a medical-cardiology blog)


NEJM blog-cardiology posts


FREE BOOKS DOWNLOAD (freebookcentre net)


Cardiology free ebook online

Assessment of left ventricular systolic and diastolic function with echocardiography

Echocardiography: Useful indices of left ventricular systolic function

The most frequently used methods for the assessment of left ventricular (LV) systolic function are LV ejection fraction (EF) and regional wall motion analysis. Two dimensional (and also M-mode) echocardiography is the most common technique used but other tests that can examine LV systolic function are tissue Doppler imaging (TDI), speckle tracking imaging, three-dimensional (3D) echocardiography, computed tomography (CT), and cardiac magnetic resonance imaging (CMR).
 M-mode echocardiography, which records the motion of cardiac structures in one dimension, can be used to obtain some indices of left ventricular (LV) systolic function. Measurements of LV dimensions are made in the parasternal long-axis view by positioning the cursor through the LV minor axis at the level of the tips of the mitral leaflets. Then fractional shortening (FS) can be calculated and even ejection fraction (EF) can be calculated with geometric assumptions (that are not accurate, if there are significant differences in regional contractile function, between various segments of the LV walls).

Fractional shortening (FS) is calculated from linear measurements

of LV dimensions from M-mode or 2D images:

FS = 100% × (LVDd – LVDs)/LVDd 

where LVDd and LVDs are the LV end-diastolic dimension and

end-systolic dimension, respectively. FS normal values: 25-45 %
FS as an index of global LV function can be problematic when there is a marked difference in regional function, in patients with a previous myocardial infarction.

Two-dimensional (2D) echocardiography for the evaluation of LV systolic function

This is the primary mode for evaluation of LV systolic function. Endocardial border motion and wall thickening can be visualized and an experienced examiner can assess regional and global contractile function and roughly estimate the ejection fraction (EF) just by visualizing the LV in various echocardiographic views ("eyeball approach"). Quantitative measurements are obtained by tracing the endocardial border in end diastole and end systole in the apical 4- and 2-chamber views using the method of discs (modified Simpson rule). The machine software divides the LV along its long axis into a series of discs of equal height. Individual disc volume is calculated as height x disc area. LV volume is then calculated as the sum of disc volumes.
The ejection fraction (EF)= stroke volume/end diastolic volume.
Stroke volume= the volume of blood ejected by a ventricle in systole= EDV-ESV. 

(EDV= end diastolic volume, ESV= end systolic volume). 
Thus,  EF=  (EDV-ESV)/ EDV. 
The left ventricular EF generally has a normal value   55%.
 It is a measure of global LV systolic function, with established prognostic significance (the lower the EF, the worse the prognosis), but it is also influenced by preload, afterload, heart rate, and valvular function. (In patients with severe aortic or mitral regurgitation, conditions causing volume overload of the left ventricle, the normal value for the EF is ≥ 60%.)  Systolic function of the left ventricle (LV) is considered as mildly reduced when EF is between 45 and 55 %, moderately reduced with EF between 30 and 45 % and severely reduced with EF< 30%.
 Left ventricular EF is a strong predictor of clinical outcome and is widely used to make clinical decisions.
EF should be calculated from volumetric measurements
by 2D echocardiography. Even more accurate measurements of left ventricular volumes and EF are obtained with three dimensional (3D) echocardiography, or magnetic resonance imaging (MRI). The latter two techniques have similar accuracy.

Echocardiography quiz. Any abnormality in the systolic function of the left ventricle?

(The answers are given at the end of the video). To see it larger after starting the video click on the symbol [] on the lower right corner.

Parasternal long axis echocardiogram of a patient with dilated cardiomyopathy

A male patient (age 40 ) with symptoms of heart failure (nocturnal and exertional dyspnea). He was diagnosed with dilated cardiomyopathy. Parasternal long axis echocardiographic view: The left ventricle and the left atrium are dilated. The anteroseptal and the posterior left ventricular wall are severely hypokinetic.  There is also a very small pericardial effusion.The coronary arteriography was normal. He was treated with ramipril (ACE inhibitor), carvedilol (beta-blocker), furosemide (loop diuretic) and  eplerenone (aldosterone antagonist).   On re-examination symptoms and left ventricular function showed improvement.

Doppler Echocardiography derived systolic indices (stroke volume)

Doppler echocardiography also provides some indices of LV systolic function, such as the stroke volume (SV), i.e. the blood volume ejected per beat. For this measurement one obtains from the apical 5 chamber view the pulse wave doppler signal of the velocity in the left ventricular outflow tract (LVOT) and also measures the diameter of the LVOT (in the parasternal long axis view at the base of the aortic valve leaflets or immediately proximal to the aortic valve).  
SV= VTI (LVOT) x area (LVOT)
VTI is the velocity time integral (also named time velocity integral-TVI) of blood flow through the LVOT during systole. 
This formula is explained as follows: VTI is calculated as the area under the curve of the Doppler velocity signal (which displays velocity on the vertical axis and time on the horizontal axis). This area of the Doppler signal is automatically calculated by the machine software, after the examiner manually traces the doppler velocity signal. It mathematically represents a velocity time integral, i.e. the sum of many products of velocity x time, each corresponding to every small time interval in systole. Since in every small time interval the column of blood moves by a distance given by the product of blood velocity x time interval, the VTI as a sum represents the total distance the column of blood has "traveled" in systole. This distance multiplied by the area of the orifice through which blood has passed, is the volume of blood which passed through the orifice in systole= the stroke volume (SV).  Assuming a circular LVOT with radius r and diameter D (=2r) : 
LVOT area = πr2=3,14r2=3,14(D/2)2 = (3,14 D2)/4= 0,785D2 
In the absence of aortic regurgitation, SV reflects the forward effective blood flow in a cardiac beat and multiplied by heart rate (beats per minute) it gives the cardiac output (= the volume of blood passing through the circulation per minute). Strictly speaking, the SV is the hemodynamic result of LV function and not a true index of systolic function. Normal values of SV: 55-80 mL.
It is better to express the normal values of stroke volume per mof body surface area: 
Normal values of SV(ml/m2):  26-54

Tissue Doppler Imaging (TDI)

Measurement of mitral ring velocities or myocardial velocities of the basal segments (velocity of the movement of these tissues along the longitudinal axis of the heart) is a simple and sensitive method for the assessment of the left ventricular systolic and diastolic function. Both peak systolic (Sm) and early diastolic (Em) mitral annular or left ventricular basal velocities are nearly always reduced in patients presenting with the clinical syndrome of systolic heart failure.
The systolic annular velocity of the mitral valve (Sm) is a measure of left ventricular longitudinal contraction (contraction of the long axis oft the ventricle). It generally correlates well with the left ventricular EF. Normally Sm of the septal mitral annulus is > 6.5 cm/sec, and Sm of the lateral mitral annulus ≥ 8 cm/sec, when measured with pulse wave tissue doppler (PW-TDI). It is better to assess the mean Sm of the septal and lateral mitral annulus (normal value > 7.5 cm/sec). Note that myocardial velocities measured by the color TDI method are lower than velocities by pulsed Doppler (typically about 25% lower).
Early myocardial damage often involves the subendocardial fibres, with impairment in long-axis contraction occuring before changes in short-axis function. Thus, the Sm is a sensitive marker of mildly impaired left ventricular systolic function, even in people with apparently preserved systolic function and a normal EF, for example in those with diastolic heart failure, or in some diabetic patients without overt heart disease. Reduced annular TDI velocities are also present in subjects with hypertrophic cardiomyopathy, (even in people having the related gene mutations, who are at the stage of subclinical disease, with no cardiac hypertrophy).
Note that whereas the Sm velocity is an index of left ventricular systolic function, the Em or E΄velocity (the peak early diastolic mitral annular velocity, which is a negative wave) is an index of LV diastolic function and the Am or A΄velocity (an end-diastolic negative wave) is an index of the systolic function of the left atrium.

Kadappu KK, Thomas L. Tissue Doppler Imaging in Echocardiography: Value and Limitations.Heart, Lung and Circulation 2015;24:224-233
  LINK Tissue Doppler Imaging in Echocardiography

Myocardial strain and strain rate imaging

In general, in myocardial segments with diminished systolic function, systolic velocities are typically reduced and there are also reductions in systolic strain and strain rate. Strain is the proportion (percentage) of change in length of the myocardium (units %) and it is negative in systole, since there is a negative change in length (shortening), and positive in diastole (because in diastole the length increases).
 Strain = L-Lo /Lo, where L is the current length and Lo is the original length of a myocardial segment. Strain rate (SR) is the rate of change of the strain value= the proportional change in length per unit of time. SR units are s-1

SR is negative in systole (because it represents the rate of proportional decrease in myocardial length) and positive in diastole (because it represents the rate of increase in length). LV longitudinal velocities measured from an apical window increase progressively from the apical toward the basal myocardial segments. Longitudinal strain and strain rate, however, are essentially similar between apical and basal segments.
The normal value of the peak systolic strain (percentage of shortening) of the left ventricle during systole in the longitudinal axis is greater than 15%. To be more accurate, lets mention that normal  peak systolic strain has a value  more negative than  -15%, usually between -15 and -25%. (The negative sign indicates a decrease in the length of the myocardium, i.e. shortening).
Peak systolic strain is influenced by preload (like the ejection fraction which is also influenced by the ventricular loading conditions) and can be used as an indicator of the total, and of the regional systolic function (when measured at a segment of the left ventricle). 
The normal value for the peak systolic strain rate of the left ventricular myocardium is between  - 1.2  and  - 2  s-1 (sec-1=1/s).
 In normal hearts the value of strain rate and strain is about the same in all myocardial segments from the base to the apex of the heart, (showing no significant difference). Conversely, myocardial velocity recorded by the tissue Doppler (in cm/s), and the displacement (change in position) of a given point of the myocardium (in mm) is greater in the basal portions and is getting smaller towards the apex.
An advantage of the percentage of myocardial deformation (strain) and of the rate of the proportional change in deformation (strain rate) is the following: Strain and strain rate is not affected by the translational motion of the heart ("bouncing" movements in the chest during systole). In contrast, the myocardial velocities recorded with tissue Doppler (TDI) are affected by the translational motion of the heart within the chest and not only by the motion of myocardial shortening in systole or lengthening in diastole.
A diminished peak systolic strain or strain rate is a sensitive marker of an impairment in systolic function.

Need more information about these modern echocardiographic techniques? In that case, here is a link for you to click on (free review article with the option to download PDF) ...

Strain and Strain Rate Imaging by Echocardiography – Basic Concepts and Clinical Applicability

Dandel Μ ,Lehmkuhl H, et al. Strain and Strain Rate Imaging by Echocardiography – Basic Concepts and Clinical Applicability. Current Cardiology Reviews, 2009, 5, 133-148. 

Assesment of left ventricular diastolic function (a summary)

Diastolic dysfunction can occur in many kinds of heart disease such as hypertensive heart disease, diabetes, hypertrophic cardiomyopathy, aortic stenosis with left ventricular hypertrophy, ischemic heart disease, restrictive cardiomyopathy, constrictive pericarditis, etc.
Assessment of left ventricular (LV) diastolic function with echocardiography is a part of the routine evaluation of patients presenting with symptoms of dyspnea or heart failure. 
There are four key variables for a quick assessment of LV diastolic function. LV diastolic dysfunction is present if more than half of these parameters meet the abnormal cutoff values. These key parameters are:
The peak early diastolic velocity of the mitral annulus , obtained from the pulse wave tissue Doppler velocity tracing of the septal and lateral mitral annulus, in the apical 4 chamber view. The velocity e΄is a marker of myocardial relaxation and it is reduced in all stages of diastolic dysfunction. A normal e΄ is a strong indication that the diastolic function is normal, except in patients with constrictive pericarditis or significant mitral regurgitation.
The normal septal e΄ ≥ 8 cm/ s (centimeters per second). The lateral e΄ is normally higher than the septal (> 10 cm/s). Abnormal values suggestive of diastolic dysfunction: a septal e΄< 7 and a lateral e΄< 10 cm/s.
 The average E/e΄ ratio. This is the ratio of the peak early diastolic mitral inflow velocity E to the average of the e΄ velocities of the septal and lateral mitral annulus. Abnormal is a ratio E/e΄>14. The ratio E/e΄ is less age-dependent than other indices of LV diastolic function. A ratio > 14, regardless of the patient's age, is almost always abnormal, suggesting elevated LV diastolic pressures (and thus, an elevated mean left atrial pressure and pulmonary capillary wedge pressure)
 The LA volume index is the maximum volume of the left atrium (LA), measured at the end of ventricular systole, divided by the patient's body surface area (BSA). LA volume index > 34 ml/mis considered abnormal, indicating left atrial dilation. LA dilation in the absence of a chronic atrial arrhythmia (e.g. atrial fibrillation), or mitral valve disease, is an indication of increased LV filling pressures, resulting in chronically elevated left atrial pressures.
 The peak tricuspid regurgitation (TR) velocity measured with the continuous wave Doppler. A peak TR velocity > 2.8 m/s is suggestive of an elevated pulmonary arterial systolic pressure (with the exception of pulmonary stenosis). This can often result from elevated pulmonary venous pressures due to the elevated left atrial pressure caused by LV diastolic dysfunction (provided that there are no indications suggestive of another cause of pulmonary hypertension e.g. pulmonary arterial hypertension, lung disease, valvular heart disease, LV systolic dysfunction).
A more detailed discussion follows:
Evaluation of left ventricular (LV) diastolic function begins with M-mode and 2D echocardiography : 
 Assessment of  LV size,  and wall thickness and 
Assessment of left atrial (LA) volume and anteroposterior dimension. 
In patients with LV diastolic dysfunction, concentric or
eccentric LV hypertrophy can be found. Pathologic LV hypertrophy is usually associated with an increased left ventricular stiffness which results in diastolic dysfunction. 
Increased LA volume reflects the effects of the increased LV filling pressures over time.  Elevated left ventricular filling pressures can occur in patients with diastolic or systolic dysfunction. LA dilation can also occur in patients with mitral stenosis or regurgitation and in patients with chronic permanent atrial fibrillation. LA volume is measured at end-systole in the apical 4 chamber view with the same method (Simpson's method of summation of disks) used for the measurement of left ventricular volume.
Doppler assessment:  To assess the mitral inflow align the Doppler beam with the inflow direction and place a 1-3 mm pulse wave (PW) Doppler sample volume between the tips of the mitral leaflets. If the  PW sample volume position is not at the valve tips, but towards the mitral annulus or towards the apex, this can alter significantly the mitral flow velocities.
E is the peak early diastolic velocity of transmitral flow and A is the peak late diastolic velocity at the time of atrial contraction. In adults with normal diastolic function E/A has a value between 0.8 and 2, but less than 2  (In younger people E>A and in middle-aged or older people E wave normally becomes lower and A increases and can be higher than A).
 In adults with normal diastolic function (normal pattern) the E > A but is less than 2A (except in very young persons), or E may be a little smaller than A, but more than 0.8 A (the E wave can be lower than the A wave by less than 20 %). The deceleration time (DT) of the E wave (time from the peak of the E wave to its end at the baseline) is 
150-200 ms (milliseconds). Isovolumic relaxation time (the time from the end of aortic flow to the beginning of mitral flow) is IVRT = 50-100 ms. Measure isovolumic relaxation time (IVRT) by placing the PW Doppler sample volume in- between LV inflow and outflow to simultaneously display the end of aortic flow and the onset of mitral E-wave velocity. 
In very young people with normal diastolic function E/A can be >2, but this is not due to an increased LA pressure as in the restrictive pattern. This pattern in young people is normal and is due to a more active relaxation of the left ventricle (LV) in early diastole so that early diastolic flow velocity is increased. It is easy to distinguish this from the restrictive pattern because these are very young individuals with no heart disease, no symptoms of effort dyspnea, normal left atrial size and normal tissue Doppler velocities of the mitral annulus.
Pulse wave Doppler of pulmonary venous flow (obtained in the apical 4 chamber view)  in adults with normal diastolic function and also in those with mildly impaired diastolic function (delayed relaxation) shows  S ≥ D.  S is the peak velocity of the systolic wave and D the peak velocity of the early diastolic wave of pulmonary venous flow. 
In people with normal diastolic function and also in those with mild diastolic dysfunction (impaired relaxation) the ratio E/e΄ is <10. E is the peak velocity of the early transmitral flow and e' (or Ea) is the peak early diastolic velocity of the mitral annulus measured by pulse wave tissue Doppler.
In more advanced forms of diastolic dysfunction (moderate or grade- 2 diastolic dysfunction with a pseudonormal pattern of transmitral flow-see below, or severe diastolic dysfunction with the restrictive pattern), the pulmonary venous flow shows S<D and tissue Doppler of the mitral annulus shows an elevated ratio E/  and a reduced velocity . According to the recent ASE (American Society of Echocardiography) and EACVI (European Association for Cardiovascular Imaging) recommendations, abnormal values indicating left ventricular (LV) diastolic dysfunction are the following: Peak early diastolic velocity (e΄) of the septal mitral annulus< 7 cm/s, e΄ of the lateral mitral annulus < 10 cm/s  and an average ratio E/e΄> 14. 
Mild (grade 1) diastolic dysfunction is characterized by the impaired relaxation (or delayed relaxation) mitral inflow pattern with E/A<0.8, E  ≤ 50 cm/s and a prolonged deceleration time DT of the mitral flow E wave ( DT> 200 ms). DT is the time from the peak to the end of the E wave. There is also prolongation of isovolumic relaxation time,  IVRT ≥ 100 ms. The IVRT is the time from the closure of the aortic valve (end of left ventricular ejection) to the opening of the mitral valve (onset of ventricular filling). In this time interval, left ventricular dimensions are constant and the mitral annulus does not move. So, the IVRT can be measured on the pulse wave tissue Doppler tracing of the mitral annulus as the time from the end of the systolic S wave to the onset of the e΄ (Ea) wave.
In grade 1 diastolic dysfunction the pulse wave Doppler of  pulmonary venous flow shows S>D, where S is the peak velocity of the systolic flow in the pulmonary vein and D the peak velocity of the early diastolic flow.
In grade 1 diastolic dysfunction mean left atrial pressure and left ventricular filling pressure is not elevated.
An important point is that age should be taken into account when evaluating LV diastolic function since the LV filling pattern in healthy elderly individuals resembles that of younger people (e.g. 40-60 years old) with mild (grade 1) diastolic dysfunction. Indeed, healthy sedentary elderly people usually have a mild degree of diastolic dysfunction (grade 1) as a result of an increased left ventricular stiffness and a slower myocardial relaxation in comparison to younger individuals.
Moderate (grade 2) diastolic dysfunction shows the same transmitral flow pattern (0.8 < E/A <2), as that observed in people with normal diastolic function. It is called pseudonormal pattern.
In the pseudonormal pattern (as well as in the normal pattern),
 150 <DT  <200 ms and IVRT is  <100 msec (range 60-100 msec).
This pattern can be distinguished from the normal pattern of diastolic inflow because at the peak of the Valsalva maneuver (which causes a reduction of preload = a reduction of ventricular filling) in people with grade-2 diastolic dysfunction, the pattern of mitral inflow takes the morphology of impaired relaxation (E< A). Other features of the pseudonormal pattern which allow its differentiation from the normal pattern are the following:
 A reduced mitral annular e΄ velocity (this is a simple way to distinguish it from normal diastolic function, which is characterized by a normal e΄). The normal and pseudonormal filling pattern have the same pattern of transmitral flow (generally E>A), but in case of a pseudonormal pattern, the  velocity is reduced. 
 The increased E/e΄ 
 The pulse wave Doppler signal of the pulmonary venous flow showing S<D (S/D <1). The peak velocity of the end systolic pulmonary vein reverse flow wave at atrial systole (AR) is elevated ( > 35 cm/s) and the duration of AR wave is increased: 
AR wave duration-mitral A wave duration    30 msec.
The pseudonormal mitral inflow pattern can change to a delayed relaxation pattern by reducing preload with diuretic treatment.

Severe diastolic dysfunction is characterized by the restrictive left ventricular filling pattern, where the markedly elevated left atrial pressure causes an increased early transmitral pressure gradient (pressure difference between the left atrium and the left ventricle) in early diastole. This causes the following findings: 
 E/A ratio >2,  a short deceleration time (DT <150 ms) and also a short IVRT < 60 ms. Due to the severe impairment of diastolic function, mitral annular e΄ velocity is usually severely reduced, the ratio E/e΄ is increased and pulmonary venous flow shows S<<D (the peak velocity of the S wave is much lower than the peak velocity of the D wave). The peak velocity of the end systolic pulmonary vein reverse flow wave at atrial systole (AR) is elevated ( > 35 cm/s) and AR wave duration-mitral A wave duration    30 msec.
The restrictive pattern is called stage 3 diastolic dysfunction if it can change, by reducing preload with diuretic treatment, to a pattern of stage 1 or 2 diastolic dysfunction. If treatment cannot change the restrictive pattern of left ventricular filling, then there is  stage-4 diastolic dysfunction which carries a severe prognosis.
Regarding the tissue Doppler examination of the velocities of the mitral annulus, the early diastolic peak velocity of the mitral annulus (e΄ or Ea) is generally a good index of diastolic function. It is higher at the lateral mitral annulus than at the septal annulus. An indication of diastolic dysfunction is an e΄ < 7 cm/s at the septal annulus, or <10 cm/sec at the lateral annulus. Moreover,  has a reasonable accuracy in identifying patients with diastolic dysfunction and pseudonormal LV filling. 
In people with cardiac disease, an increased E/e΄ ratio can provide an indication of the presence of an elevated left ventricular filling pressure and pulmonary capillary wedge pressure, 
if the ratio is > 15 for the septal mitral annulus or > 13 for the lateral mitral annulus. For the septal mitral annulus, an E/e΄ between 10 and 15 is borderline, and cannot predict if the left ventricular diastolic pressures are elevated or normal.When an average (septal, and lateral) e΄ velocity is available, a cutoff value of 14 should be considered for the E/e΄ ratio.


LINK: Cardiology book- Table of contents

Bibliography and links 

Guideline ASE -2016 : Echocardiographic evaluation of diastolic function
Cardiology free e-book online

Lang, R. M., Badano, L. P., Mor-Avi, et al. Recommendations for Cardiac Chamber Quantification by Echocardiography in Adults: An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. Eur Heart J Cardiovasc Imaging 2015; 16 (3 ), 233-271.

Atrial septal defects (ASDs) and ventricular septal defects (VSDs)

Atrial septum defect (ASD)

An atrial septal defect (ASD) is a congenital defect in the interatrial septum allowing a direct communication between the atria. It is common, about 10% of all congenital heart disease cases, more common in females. (male to female ratio of 1:2).
There are three main types of ASDs:
Secundum ASD, the most common type (70-75% of ASDs) is located in the central portion of the interatrial septum.
Primum ASD, about 20% of all ASDs, (or partial endocardial cushion defect ) is in the lower part of the septum, near the atrioventricular valves. This is the second most common type. 
Sinus venosus defect is located near the entrance of the superior vena cava (SVC) or the inferior vena cava IVC to the right atrium and is a less common type (about 5-10% of all ASDs), commonly associated with a partial anomalous pulmonary venous return. 
An ASD causes an abnormal flow between the atria, called a left to right (L-R) shunt, i.e. flow of blood through the defect with a direction towards the right heart chambers. This results in a volume overload to the right atrium and right ventricle and an increase in blood flow through the pulmonary arterial circulation. The magnitude of the L-R shunt depends upon the size of the defect and also the relative pressures on the left and right sides of the heart.
The patients are asymptomatic in the majority of cases but large defects can be associated with recurrent respiratory infections, shortness of breath on exertion (dyspnea), easy fatiguability, or atrial arrhythmias (palpitations). Patients with large defects, late in the course can develop complications, such as right heart failure, or pulmonary arterial hypertension PAH (see also chapter Pulmonary Hypertension). Another rare complication of an ASD is a stroke due to paradoxical embolism (caused by a thrombus reaching the right atrium from the venous circulation and then crossing the ASD and entering the left cardiac chambers and the arterial circulation).
In a moderate or large ASD, physical examination findings usually include a widely split and fixed second heart sound (S2) and a systolic ejection murmur of low intensity, (grade 2 to 3/6) at the upper left sternal border (at the area of the pulmonary artery due to the increased blood flow through the right heart and the pulmonary artery).
In case of a large ASD with a large L-R shunt, a mid-diastolic rumble may be audible at the left lower sternal border, i.e. at the tricuspid area due to the increased flow through the valve.
The typical auscultatory findings often are not present in infants and toddlers, even with a large defect, because at this age the right ventricle often is not compliant enough to allow a large L-R shunt.
The ECG usually shows a RBBB, or an incomplete RBBB with an rsR′ pattern in V1 (also see chapter The Electrocardiogram -ECG . In case of a moderate to large ASD, right QRS axis deviation (frontal axis between +90 to +180°) and/or other indications of right ventricular hypertrophy may be present , but in the case of an ostium primum defect there is an RBBB pattern with a left QRS axis.
Chest radiographs if the shunt is moderate or large, show cardiomegaly (with right atrial and right ventricular enlargement), increased vascular markings in the lungs and a prominent main pulmonary artery (at the mid-left heart border).
Echocardiography in a patient with an atrial septal defect (ASD) shows the position and the size of the defect and the abnormal flow (shunt) through the interatrial septum. If the defect is moderate to large, echocardiography also shows a dilated right atrium, right ventricle, and pulmonary artery. The finding of dilated right heart chambers proves that the ASD is hemodynamically significant and is in favor of ASD closure.
Cardiac catheterization is not necessary for the diagnosis of an ASD, but it can be necessary in the case of significant pulmonary hypertension to decide if the defect should be closed.

 Natural history of atrial septal defects (ASDs)

Spontaneous closure of an ASD often occurs in patients with secundum ASDs with a diameter < 8mm before the age of 1.5 years, but an ASD >8 mm rarely closes spontaneously.
After the age of 4 years, spontaneous closure is not likely to occur.
Spontaneous closure may occur only in secundum defects. It does not occur in primum or sinus venosus ASDs. If a large ASD is left without closure, pulmonary hypertension and signs of right heart failure can develop in the third or fourth decade of life.

Management of atrial septal defects

 In a patient with an ASD exercise restriction is not required unless the patient has symptoms.
Children with a secundum atrial septal defect are usually observed without intervention for at least the first 3 years of life, due to the possibility of spontaneous closure.
Closure of an ASD in children or adults, is indicated when there is evidence of right ventricular volume overload (a dilated right ventricle) in the presence of an atrial septal defect with size > 5 mm and in the absence of irreversible pulmonary arterial hypertension. In this case measurement of the ratio of pulmonary to systemic flow (Qp/Qs) is not necessary to confirm that the ASD is hemodynamically significant. If the ratio Qp/Qs is used, then the defect is considered hemodynamically significant and closure is decided if Qp/Qs ≥ 1.5:1, in the absence of irreversible pulmonary arterial hypertension. Closure of an ASD can be surgical or with a catheter device. Device closure is the preferred method when feasible, but it is only feasible in patients with a secundun ASD with a diameter ≥5 mm but < 32 mm for Amplatzer device and <18 mm for Helex device, provided there is enough rim ( at least 4 mm) of septal tissue around the defect ( for the appropriate placement of the device). The rim around the ASD is measured with 2-D echocardiography in 4 directions. After device closure of an ASD antiplatelet treatment is given, with aspirin 80-100 mg per day for 6 months. In children, device closure can be performed preferably if they weigh >15 kg.In the rare case of an ASD with pulmonary hypertension, closure of the ASD is indicated if systolic pulmonary arterial pressure is <2/3 of systemic systolic blood pressure and pulmonary vascular resistance <2/3 of systemic vascular resistance. If systolic pulmonary artery pressure and pulmonary vascular resistance exceed the above limits, ASD closure can be decided only when there is a L-R shunt with a ratio of pulmonary to systemic flow Qp / Qs of at least 1.5: 1,  provided that pulmonary hypertension is reversible.

A case (Video) showing the ECG and echocardiographic features of this condition

Ventricular septal defects (VSDs)

There are four anatomic types depending on the location of the defect.
Perimembranous or membranous VSD is the most common type (70%) and it involves the membranous septum, a small part of the septum immediately beneath the aortic valve. These defects usually also have an accompanying defect of the adjacent muscular septum and depending on the location of this defect they are further classified as perimembranous trabecular, perimembranous inlet or perimembranous outlet.
Another type of VSDs are inlet defects, which are located beneath the septal leaflet of the tricuspid valve.
Outlet VSDs, also called conal or supracristal, are located in close proximity to the annulus of the aortic valve and of the pulmonary valve. These two valve annuli form part of the defect's rim. A common complication of this defect involves herniation of the right coronary cusp of the aortic valve through the defect. This can cause a reduction of the shunt, but also it often causes progressive aortic regurgitation. It may also result in a degree of obstruction of the right ventricular outflow tract.
Trabecular (muscular) VSDs may be central or apical, depending on their location in the muscular interventricular septum.

Pathophysiology of ventricular septal defects (VSDs)

The main pathophysiologic feature of a VSD is a left to right (L-R) shunt. The magnitude of the shunt depends on the size of the defect and the pressure difference between the two ventricles, which in turn depends on the pulmonary arterial pressure and thus, on the level of the pulmonary arterial resistance. The larger the size of the defect and the lower the pulmonary vascular resistance, the larger the L-R shunt. 
A small defect does not cause any ventricular dilation or hypertrophy, a moderate-sized defect usually can cause left ventricular hypertrophy or dilation and a large defect can cause hypertrophy or dilation of both ventricles. Moreover, a small VSD, also called a restrictive VSD, has a large resistance and results in a significant pressure gradient between the two ventricles and a small shunt with Qp/Qs<1.5 :1 and pulmonary systolic pressure/systemic systolic pressure<0.3. 
On the contrary, a large nonrestrictive defect will cause a large shunt with Qp/Qs >2.2 and a small pressure gradient between the two ventricles. Pulmonary arterial systolic pressure/systemic systolic arterial pressure will be > 0.6. With a VSD of a moderate size these values will be intermediate, with a Qp/Qs between 1.5 and 2.2.
A large VSD if left untreated will cause over the years a progressive rise of the pulmonary vascular resistance, due to progressive obstructive changes of the pulmonary arterioles.This leads to an elevated pulmonary arterial and right ventricular systolic pressure resulting in a reduction in the magnitude of the L-R shunt. This condition has also effects on the ventricles with the left ventricle decreasing in dimensions, whereas the size of the right ventricle increases. When the obstructive changes in the pulmonary vasculature become serious and irreversible, bidirectional shunt develops across the VSD (or even net right to left R-L shunt) and this leads to the development of cyanosis because unoxygenated venous blood from the right ventricle enters the left ventricle and the systemic circulation.

Symptoms and signs of a VSD

In infants and children, a small restrictive defect does not cause any symptoms and is diagnosed because of the auscultation of a murmur. A large non-restrictive VSD can cause dyspnea, failure to thrive and signs of congestive heart failure early, even at the age of 2-3 months, or later. In adults a small restrictive defect will be asymptomatic (and the only sign will be the murmur), a defect of a moderate size may cause dyspnea on exertion and palpitations due to the development of atrial fibrillation, whereas a large non-restrictive VSD can cause symptoms and signs of right heart failure and central cyanosis (Eisenmenger syndrome). Apart from cyanosis patients with Eisenmenger syndrome often have edema (due to the right-sided heart failure) and clubbing.
The murmur of a VSD is pansystolic (holosystolic, i.e. it is present during the whole duration of systole), grade 2/6-5/6, best heard at the lower left sternal border. The murmur can be accompanied by a palpable systolic thrill (also at the lower sternal border). The murmur occasionally can be early systolic in patients with small muscular VSDs.
Murmurs of increased flow may be audible if the shunt is moderate to large, such as a systolic murmur due to increased flow through the pulmonary valve, or an apical diastolic rumble due to increased flow through the mitral valve (The L-R shunt causes not only increased flow through the pulmonary valve and the pulmonary circulation , but also an increased flow through the mitral valve which also leads to volume overload of the left ventricle. This happens because as a result of the increased flow through the pulmonary circulation, there is also an increased pulmonary venous return of blood to the left atrium).
If pulmonary hypertension develops, the pulmonic component (P2) of the second heart sound becomes loud (generally a loud P2 is a sign indicative of pulmonary hypertension, regardless of the etiology). With the development of pulmonary hypertension the systolic murmur of a VSD becomes less prominent and if severe pulmonary hypertension develops the murmur usually disappears. This happens because in the presence of pulmonary hypertension there is a smaller pressure difference between the left and right ventricle resulting in a reduction in the flow of blood through the defect from the left into the right ventricle.

The ECG and the chest X-ray in patients with a VSD

In patients with a small restrictive VSD both the ECG and the chest X-ray are usually normal. In patients with a defect of moderate size the ECG will usually show features of left ventricular and left atrial hypertrophy and enlargement respectively and in a large non-restrictive defect left atrial enlargement with combined ECG features of left and right ventricular hypertrophy. In the case of pulmonary vascular obstructive disease with pulmonary hypertension the ECG usually shows features of isolated right ventricular hypertrophy.
The chest X-ray in the case of a VSD with a moderate or large shunt will show enlargement of the cardiac silhouette (due to dilation of the left atrium and ventricle and occasionally also the right ventricle). A moderate to large shunt will also result in increased pulmonary vascular markings (to a degree that is in direct proportion to the magnitude of the L-R shunt). If pulmonary vascular obstructive disease with significant pulmonary arterial hypertension has developed, the main pulmonary artery and its main branches at the hila of the lungs are dilated, while there are markedly reduced pulmonary vascular markings at the lung fields (this is a typical chest X-ray pattern of pulmonary arterial hypertension of any cause).

Echocardiography in a patient with a ventricular septal defect

Transthoracic echocardiography can identify the presence of a VSD, from the turbulent jet of flow across the interventricular septum, and it can also demonstrate the location and size of the defect and it can provide information about its hemodynamic significance. An increased left ventricular and left atrial size (and also a Qp/Qs>1.5) indicates the presence of a significant (moderate or large) L-R shunt.
 With the exception of the trabecular VSDs, a useful marker for the identification of the type of the VSD is its location relative to the valves. A membranous defect is near the aortic valve, an infudibular defect near both the pulmonic and the aortic valve and an inlet defect near the tricuspid valve.

From the peak gradient across a VSD measured with continuous wave Doppler, by subtracting this gradient from the systolic arterial pressure, the right ventricular systolic pressure (RVSP) can be calculated. RVSP is equal to PASP (pulmonary artery systolic pressure) if there is no coexisting stenosis of the right ventricular outflow tract or the pulmonary valve.
Cardiac catheterization

Cardiac catheterization is not needed for the diagnosis of a VSD, but only if there is pulmonary hypertension to calculate the pulmonary vascular resistance and in some cases where echocardiography does not fully clarify the anatomic diagnosis, or if there is a significant possibility of coronary artery disease. In a VSD with a L-R shunt cardiac catheterization will reveal an elevated oxygen saturation in the pulmonary artery, and this is also an indication that there is no severe pulmonary hypertension. In case that severe pulmonary hypertension has developed this will result in a significant reduction in the L-R shunt and so, much less oxygenated blood from the left ventricle will enter the right ventricle and the pulmonary artery. Therefore in this case the oxygen saturation in the pulmonary arterial blood will be low. In these cases simultaneous comparison of the pulmonary arterial and systemic blood pressures is mandatory, as well as calculation of the pulmonaty vascular resistance and assessment of its responce to vasodilators. This assessment is necessary to demonstrate if pulmonary arterial hypertension is reversible or irrreversible.

The natural history of ventricular septal defects (VSds)

Membranous and muscular VSDs can decrease in size with time, or close spontaneously. Until the age of 6 months spontaneous closure occurs in about 30-40% of these defects.On the contrary, inlet or infudibular defects do not decrease in size and thus they also do not demonstrate spontaneous closure.
In infants with large VSDs congestive heart failure can occur but usually after the first 6-8 weeks of life, because at that time the pulmonary vascular resistance has fallen enough to allow a large L-R shunt which can cause severe volume overload of the left heart chambers due to the increased pulmonary venous return.
Large VSDs can cause a slowly progressive elevation of the pulmonary arterial pressure. This is the result of progressive obstructive changes in the pulmonary arterioles as a reaction of the pulmonary arterial circulation to the chronically increased blood flow. Although pulmonary vascular changes may begin early, even at an age of 6-12 months, severe pulmonary arterial hypertension leading to a R-L shunt and the appearance of cyanosis usually does not occur before the second decade of life.
Another complication that can develop in some infants with a large VSD is infudibular stenosis, i.e. stenosis of the right ventricular outflow tract just below the pulmonary valve. This reduces the L-R shunt and in some cases it may even cause the development of a R-L shunt with cyanosis, a condition similar to the tetralogy of Fallot.

Treatment of the patient with a VSD

In infants with large defects usually medical treatment is given initially (furosemide, ACE inhibitor) to control heart failure, while waiting for the gradual spontaneous decrease in the size of the defect, but if this does not happen or if there is inadequate control of the manifestations of congestive heart failure then closure of the defect is decided.
In children and adults indications for VSD closure are the following: A VSD of a hemodynamically significant size, i.e a defect causing symptoms or dilation of the left ventricle, or a gradual worsening in left ventricular function, or Qp/Qs> 1.5:1 or an elevation in pulmonary arterial pressure > 50 mmHg but in the last case with a pulmonary vascular resistance <7 Wood Units. If the pulmonary vascular resistance > 7 Woods then the defect is closed if there is a shunt with a Qp/Qs> 1.5 : 1 or reactivity of the pulmonary circulation to vasodilators has been demonstrated (a fall in pulmonary vascular resistance and pulmonary arterial pressure with vasodilators). If there is irreversible pulmonary arterial hypertension and Eisenmenger syndrome then closure of any pathologic communication between the left and right circulation (such as a VSD or an ASD) is contraindicated.
Another indication of closure of a VSD is related to the development of aortic regurgitation as a complication of an outlet VSD, which can be progressive. There is an indication for closure if such a VSD causes more than mild AR.

LINK : Cardiology book- Table of contents

Congenital heart disease. A concise introduction (overview)

Congenital heart disease. A concise overview

This chapter is a brief, general introduction to congenital heart disease. The diagnosis and treatment of specific congenital heart defects will be discussed in other chapters.

Definition and causes of congenital heart disease

Congenital heart disease includes cardiac lesions that are present from birth. The most common congenital defects in humans are congenital heart defects. The overall incidence of congenital heart disease is about 1 in 100 infants (live births). The incidence of moderate to severe congenital heart disease is approximately 6/1000 infants.
Remarkable improvement in outcomes for patients with congenital heart disease has occurred over the last 50 years, because of the progress in the early diagnosis and in the development of surgical or catheter-based treatment. This has resulted in a growing population of adults with congenital heart disease (approximately 85% of all newborns with congenital heart disease will reach adulthood). As a result, the number of adults with congenital heart disease is larger than the number of children with such disease.
Congenital heart disease usually results from the abnormal embryonic development of a normal cardiac structure or failure of a structure to progress beyond a certain stage of embryonic development.The causes of congenital heart disease are multiple, genetic and environmental factors affecting cardiac development in the uterus. Genetic causes include gene mutations and chromosomal anomalies. Environmental factors include viral infections in pregnancy (such as rubella), alcohol abuse during pregnancy, effects of certain drugs during pregnancy. In most cases, the cause of a congenital heart defect in a given patient is not known.
[The term " syndrome" will often be encountered in this chapter, and notably, although every doctor understands its meaning, some cannot give its exact definition. A definition of "syndrome" is a combination of symptoms, or abnormal clinical or laboratory findings that constitute a distinct clinical picture because they result from a single cause or because they very commonly occur together and have a linked etiology or pathophysiology.]

Some known causes of congenital heart disease include:

Fetal alcohol syndrome (resulting from alcohol abuse by a pregnant woman, it is associated with cardiac defects, but also non-cardiac defects, such as microcephaly, micrognathia, and growth retardation).
Maternal rubella [it can cause patent ductus arteriosus (PDA) and pulmonary stenosis and also non-cardiac lesions such as microcephaly, cataracts, and deafness]
Maternal systemic lupus erythematosus (it can cause fetal complete heart block).
Many genetic defects are associated with congenital heart disease, including:
Marfan syndrome caused by a gene mutation (it is associated with aortic dilatation and aortic regurgitation, mitral valve prolapse and regurgitation). 

Holt-Oram syndrome, also caused by a gene mutation (autosomal dominant), which is characterized by an atrial septal defect combined with skeletal anomalies of the upper extremities, such as a short thumb, or a thumb with 3 phalanges or a short antebrachium.
William's syndrome, a genetic disorder characterized by distinctive facial features ("elfin facies"), cardiovascular defects such as supravalvar aortic stenosis and other features such as neonatal hypocalcemia and later in life mild mental retardation is evident, usually with a friendly talkative personality. The inheritance is autosomal dominant.

Examples of chromosomal anomalies associated with congenital heart disease are: 
Turner syndrome (XO) is the condition in which a female is partly or completely missing an X chromosome. It is associated with coarctation of the aorta, congenital aortic stenosis and atrial septum defect (ASD).
Trisomy 21, also called Down syndrome (it is associated with endocardial cushion defects, atrial septal defect of the ostium primum type, ventricular septal defect).

General classification of congenital heart defects

Congenital heart lesions can be classified as acyanotic (defects that do not cause cyanosis) or cyanotic (defects that cause central cyanosis due to a right- to- left shunt). Cyanosis is a blue discoloration of the mucous membranes or the skin caused by an increased amount of reduced hemoglobin (hemoglobin not combined with oxygen). Central cyanosis occurs when the circulation is mixed as a result of a right-to-left shunt (pathologic flow of unoxygenated blood from a right-sided cardiac chamber to a left-sided one). 

Acyanotic congenital heart defects include:

Ventricular or atrial, or other cardiac communications with left-to-right shunting such as: ventricular septal defect [ An opening in the ventricular septum. The most common type of congenital heart disease encountered in children]
atrial septal defect [An opening in the atrial septum.The most common congenital heart defect encountered in adults, excluding mitral valve prolapse and bicuspid aortic valve]
partial anomalous pulmonary venous return, [ One or more of the pulmonary veins connect to the superior vena cava or to the right atrium.This condition has many of the physiologic characteristics of an atrial defect and it is also often associated with such a defect (in 80-90% of cases).]
patent ductus arteriosus (PDA) [PDA is the second most common congenital heart defect encountered in adults (after ASD) It is a persistent communication between the descending aorta and the left pulmonary artery at the level of the left subclavian artery. A characteristic sign usually present is a continuous murmur (heard in both systole and diastole) which is best heard on the area under the left clavicle]

Congenital abnormalities of the heart valves and great vessels, e.g:congenital aortic stenosis due to a congenital bicuspid aortic valve
[An aortic valve with two cusps instead of three. Studies have reported an incidence of about 0.5-2 % in the general population. In many- but not all- cases the valve may have a dysfunction, stenosis or regurgitation]coarctation of the aorta, [This is usually a narrowing of the descending aorta just distal to the origin of the left subclavian artery, caused by an indentation protruding in its lumen opposite to the entry of the ductus arteriosus, so-called juxtaductal aortic coarctation. Much less commonly there is an elongated, narrowed segment of the proximal descending thoracic aorta that can also involve the arch. Aortic coarctation is often associated with a bicuspid aortic valve and usually it is diagnosed in childhood because of hypertension or a heart murmur.]
congenital subvalvular aortic stenosis [This is a stenosis of the left ventricular outflow tract caused by a discrete fibrous or fibromuscular membrane, or a diffuse, fibromuscular, narrowing of the left ventricular outflow tract (like a narrow tunnel), or rarely accessory tissue on the basal anterior mitral leaflet, or an anomalous chordal attachment of the mitral valve]
 or supravalvular aortic stenosis  [A localized or diffuse narrowing of the ascending aorta distally to the superior margin of the sinuses of Valsalva, which may occur sporadically, as a manifestation of elastin arteriopathy, or as a manifestation of Williams syndrome]
pulmonary stenosis [This term is used for an obstruction (narrowing) to the right ventricular outflow, that may be located at the valvular, subvalvular, or supravalvular level. The most common form is valvular pulmonary stenosis]
congenital mitral stenosis [due to a parachute mitral valve where all chordae tendinae are connected to a single papillary muscle, congenitally dysplastic mitral valve with fused commissures, hypoplastic (small) mitral annulus or a double orifice mitral valve, or mitral stenosis due to the presence of a supravalvular ring].
 Other lesions such as 
Congenital abnormalities of the coronary arteries.
Congenitally corrected transposition of the great arteries [A rare congenital disorder, where the ventricles are in a reversed position, i.e. the right ventricle is in the position of the left ventricle, receiving blood from the left atrium and ejecting blood into the aorta, whereas the left ventricle is receiving blood from the right atrium and ejecting it into the pulmonary artery. This condition is usually diagnosed late in childhood or in early adult life, with the patient presenting with complete heart block or heart failure due to the decompensation of the right ventricle which is the systemic ventricle in this condition, supporting the systemic circulation]

Cyanotic congenital heart defects include :

The two most common in order of frequency are 
Tetralogy of Fallot (TOF) [ It is the constellation of four findings: right ventricular outflow obstruction, a large subaortic ventricular septal defect, an overriding aorta, and right ventricular hypertrophy. Frequently an atrial septum defect may coexist and then the condition is called pentalogy." Common manifestations of TOF include cyanosis, clubbing, dyspnea on exertion, hypoxic spells and squatting ]
Complete transposition of the great arteries (TGA) [ The reversal of the relation of the aorta and pulmonary artery to the ventricles, i.e the aorta arises from the right ventricle and the pulmonary artery from the left ventricle. The common classic type of complete TGA is called d -transposition, with the aorta located anteriorly and to the right of the pulmonary artery. In cases of TGA where the aorta lies to the left of the pulmonary artery, the condition is called l -transposition.) Because in complete TGA the systemic and the pulmonary circulation are two separate circuits, defects that permit a communication of the two circulations always coexist, such as an atrial septum defect, a patent foramen ovale, a ventricular septum defect or a patent ductus arteriosus). The presence of such a communication is necessary for survival. ]
Less common malformations such as: 
Pulmonary atresia, 
Hypoplastic left heart, 
Ebstein anomaly with an ASD  [In Ebstein anomaly there is an inferior apical displacement of the septal and posterior leaflets of the tricuspid valve into the right ventricle. This results in an "atrialized" part of the right ventricle, i.e. a part of the ventricle which has become a portion of the right atrium because of the apical displacement of the tricuspid valve. The remaining right ventricle below that part is small and often dysplastic. The anterior leaflet of the tricuspid valve is large and has a sail-like appearance. Among the patients with Ebstein anomaly, 50% have a communication between the atria, i.e. a patent foramen ovale or a secundum atrial septal defect. Another abnormality that can coexist in patients with Ebstein's anomaly is Wolff-Parkinson-White syndrome since 25% of these patients have one or more accessory pathways of atrioventricular conduction].

Patients with congenital heart defects are divided into three categories according to the surgical status:
unoperated, surgically palliated (patients that have undergone operations that partially improve their condition without complete correction of their defect) or physiologically repaired (complete or near-complete surgical repair of the defect). 

General problems and complications in patients with congenital heart disease

Patients with congenital heart disease can develop various symptoms and complications. In adults with congenital heart disease, there are certain symptoms, particularly progressive dyspnea on exertion and syncope, that should prompt a thorough evaluation.
Arrhythmias present a common problem in adults with congenital heart disease. Arrhythmias in these patients often originate near the myocardial scars of previous surgical operations. The most common arrhythmias that occur, are supraventricular arrhythmias, such as atrial flutter or atrial fibrillation. 
Ventricular tachycardia (VT) may occur in adults with congenital heart disease as a late complication of prior ventriculotomy or patching of a ventricular septal defect. VT is an important arrhythmia because it can cause sudden death. In adults with corrected tetralogy of Fallot (TOF) the incidence of ventricular arrhythmias is  0.5% -5 %. Risk factors for the occurrence of ventricular arrhythmias in such patients include an older age at the time of surgical repair,  a significantly prolonged QRS interval (>180 ms) and significant dilation of the right ventricle.
Pulmonary hypertension is a common complication of certain congenital heart defects. There are two possible causes of pulmonary hypertension, depending on the type of congenital heart disease:
1. Pulmonary hypertension as a result of  pulmonary venous
hypertension due to elevated left-sided filling pressures, 
2. Pulmonary hypertension as the result of a left to right shunt, i.e an abnormal communication between the left and right heart chambers with blood flow from a left heart chamber towards a right heart chamber. This increases flow in the pulmonary arterial circulation and can result over the years in pulmonary arterial hypertension (PAH).
Shunts proximal to the tricuspid valve such as atrial septal defects or partial anomalous pulmonary venous return uncommonly result in pulmonary hypertension ( about 15 % of cases), whereas shunts distal to the tricus­pid valve, for example a large ventricular septal defect, more commonly cause pulmonary hypertension

Left to right (L-R) shunt lesions are common types of congenital heart disease. As a general rule, a significant L-R shunt is  characterized by a ratio of pulmonary flow to systemic flow 
1.5 : 1, but this rule may not apply to adults if pulmonary hypertension has developed. In such a case, the elevated pressures on the right side and the reduced right ventricular compliance gradually cause the reduction of the L-R shunt flow. When pulmonary arterial hypertension becomes severe, the L-R shunt may reverse, resulting in the development of a right to left (R-L) shunt, i.e. an abnormal flow of desaturated blood from a right heart chamber to a left heart chamber. This causes a reduction in the hemoglobin-oxygen saturation of the arterial blood (arterial desatura­tion) with the development of cyanosis, a condition called Eisenmenger syndrome.
Cyanosis in congenital heart disease occurs when persistent mixing of desaturated blood to arterial blood, due to a R-L shunt, results in hypoxemia (reduced oxygen content of the arterial blood and a fall in hemoglobin saturation with oxygen). In such cases, the body has some adaptive mechanisms to increase oxygen delivery to the tissues, such as a rightward shift in the oxyhemoglobin dissociation curve, a rise of the hematocrit (secondary erythrocytosis), and a rise in cardiac output. Chronic hypoxemia and erythrocytosis in patients with cyanotic congenital heart disease can cause the development of various complications, such as: 
 hematologic (hyperviscosity, iron deficiency, and bleeding diathesis)
 neurologic (possible complications include cerebral hemorrhage or paradoxical cerebral embolization from a venous thrombus entering the systemic circulation through a congenital heart defect)
renal (proteinuria, hyperuricemia, or renal failure)
pulmonary (pulmonary in situ arterial thrombosis, or pulmonary hemorrhage)
and rheumatologic complications (gout and hypertrophic osteoarthropathy causing arthralgias. Another musculoskeletal manifestation of cyanotic congenital heart disease is digital clubbing, which is an enlargement of the distal segments of the fingers. Clubbing is usually an indication of an underlying disease such as a cyanotic congenital heart disease, a chronic pulmonary disease or lung cancer, infective endocarditis, inflammatory bowel disease, cirrhosis of the liver. But there are also cases where clubbing is idiopathic or hereditary without any underlying disease.)
Symptoms of hyperviscosity include headaches, dizziness, visual disturbances, altered mentation, fatigue and paresthesias.
Another important issue related to congenital heart disease, is pregnancy in a woman with congenital heart disease. The presence of congenital heart disease is associated with an increased risk for peripartum complications. However, maternal congenital heart disease is not a contraindication to pregnancy unless certain high-risk features are present, such as pulmonary hypertension, cyanosis, decompensated heart failure, aortic aneurysm, severe valve disease.


LINK: Cardiology book- Table of contents

Bibliography and links 

Triedman JK, Newburger JW. Trends in Congenital Heart Disease.The Next Decade. Circulation. 2016;133:2716-2733

 ESC Guidelines for the management of grown-up congenital heart disease (new version 2010)  European Heart Journal (2010) 31, 2915–2957

Congenital Heart Disease in Children

Guidelines for Evaluation and Management of Common Congenital Cardiac Problems in Infants, Children, and Adolescents
A Statement for Healthcare Professionals From the Committee on Congenital Cardiac Defects of the Council on Cardiovascular Disease in the Young, American Heart Association

Canadian cardiovascular society guidelines on the management of adult congenital heart disease 2009