Diseases of the Heart | Humans | Medical Science

Here is a list of twelve major heart diseases found in humans.

1. Congenital Heart Disease:

Congenital heart disease is due to defective development of heart of the foetus in utero, resulting in structural or positional abnormality present at birth. Those with major defects may die soon after birth but others survive with some functional deficit. Most important developments take place during the third to eighth week of foetal life.

The primitive heart has four parts:

(1) Sinus venosus

(2) Auricle and auricular canal

(3) Ventricle

(4) Bulbus Cordis

The primitive heart resembles a tube. In the fourth week of foetal life, all these structures divide into two by a partition called septum. The inter-auricular septum divides the auricle into two chambers. A small valve-like opening (foramen ovale) closes after birth. The inter-ventricular septum divides the ventricle into two parts. The septum of truncus arteriosus divides into two major vessels, the aorta and pulmonary artery.

During this time, the cardiac tube begins to get folded in such a way (S-shaped manner), that the left and right ventricles are juxtaposed with the division of truncus arteriosus viz. aorta and pulmonary artery respectively.

Sinus venosus joins right auricle at sino-auricular node (S.A. Node). The primitive auricular canal forms the A.V. node, bundle of His and its branches. The bulbus cordis gets incorporated in the right ventricle also to some extent in left ventricle. The spiral septum of truncus arteriosus divides it into aorta and pulmonary artery.

Various processes during development occur simultaneously. So it is quite obvious that if some process or processes remain incomplete, single or multiple defects can result in heart of a newly born baby. It is easy to imagine, that many types of congenital heart disease may result, depending upon the site and stage of arrested growth. For instance if the septa dividing auricle, ventricle or truncusarteriosus remain completely developed, it will result in atrial septal defect (ASD), ventricular septal defect (VSD) and aorto-pulmonary window respec­tively.

In some congenital heart diseases (CHD) the arterial and venous blood may get mixed at the site of the defect. If venous blood is shunted to arterial side without passing through lungs, cyanosis will be evident. This happens in Fallot’s tetralogy. If arterial blood is shunted to venous side from left ventricle to right ventricle (VSD) or left auricle to right (ASD), there will be no cyanosis.

Hence congenital heart disease may be cyanotic or acyanotic. Acyanotic variety later on may become cyanotic if the reversal of blood flow occurs due to high pressure in pulmonary circuit.

Congenital defect may occur without any shunt. For instance when truncus arteriosus does not develop normally, it may result in aortic valve stenosis, subvalvular stenosis or coarctation of aorta. Obviously there will be no cyanosis.

Clinicians have to remember that congenital heart lesions need radical cure but before patients are surrendered to knife, they have to be protected against infections, because they are liable to get infective endocarditis. In some of the lesions like PDA, VSD, ASD and even Fallot’s tetralogy, surgical operation produces satisfying results.

It is difficult to pinpoint the aetiology of an established congenital heart disease. However, certain genetic factors such as chromosomal abnormalities and hereditary diseases are important in the aetiology of congenital heart disease.

The following factors are relevant:

(1) Trisomy 21 is associated with VSD, and ASD and trisomy 18 with VSD and PS.

(2) Some hereditary diseases associated with congenital diseases e.g. Ellis-Van-Crevel syndrome associated with single atrium. Holt-Oram associated with atrial septal defect, Garvell- Lange-Neilsen syndrome associated with prolonged QT interval and sudden death.

(3) Kartagener syndrome is associated with dextrocardia.

(4) Teratogens are well-known causes.

(5) Many other drugs include folic acid antagonists; anticonvulsive drugs-like dilantin, lithium chloride used in mental disorders and prolonged use of alcohol. Viruses like congenital rubella are associated with patent ductus arteriosus and stenosis of the pulmonary artery branches.

(6) Exposure to radiation and use of antimitotic drugs during pregnancy.

Congenital heart diseases can be broadly divided into three groups: cyanotic, acyanotic and miscellaneous types.

(A) Congenital Cardiac Disease with Cyanosis:

(1) Tetralogy of Fallot

(2) Double outlet right ventricle with pulmonary stenosis

(3) Pulmonary atresia

(4) Tricuspid atresia

(5) Eisenmenger syndrome (ASD, VSD, PDA due to reversal of shunt)

(6) Transposition of the great vessels

(7) Ebstein’s disease

(8) Truncus arteriosus

(9) Single ventricle

(B) Without Cyanosis:

(1) Ventricular septal defect

(2) Atrial septal defect

(3) Osteum primum defect

(4) Endocardial cushion defect

(5) Patent ductus arteriosus

(6) Pulmonary stenosis in different forms

(7) Coarctation of the aorta

(8) Anomalous pulmonary venous return

(9) Congenital aortic stenosis

(10) Congenital mitral stenosis and mitral insufficiency.

(C) Miscellaneous Types:

(1) Anomalous origin of the coronary arteries.

(2) Marfan’s syndrome primary pulmonary hypertension.

(3) Some abnormal metabolic diseases which are very rare.

It is customary to describe symptoms and signs of pure congenital lesions, but it should be realised that in many cases there is more than one congenital lesion present, hence signs are modified. Though various newer diagnostic tools are now available e.g. echocardiography (M- -Mode and two-dimensional), Doppler echocardiographic studies, nuclear angiography, exercise testing, subtraction digital angiography and contrast angiocardiography, every physician should put great emphasis on clinical examination.

History taking, symptomatology, routine radiology, screening of heart and ECG along with good physical examination should be the basis of routine cardiology. Provisional diagnosis must make before looking for advanced diagnostic aids.

2. Cyanotic Heart Disease:

Tetralogy of Fallot:

Definition:

Though tetralogy of fallot has been defined to be a combination of right ventricular hypertrophy, ventricular septal defect, obstruction of the right ventricular outflow tract and dextro-position of the aorta, the main determining relation producing these symptoms and signs are from obstruction of the right ventricular outflow tract either in the form of pulmonary stenosis or infundibular stenosis.

Ventricular septal defect is usually large and it is situated just below the aortic valve.

Hemodynamics:

In this condition, venous blood is shunted from the right ventricle into the left ventricle because of the obstruction at the right ventricular outflow level resulting in cyanosis.

Clinical Features:

The physical signs are predominantly, cyanosis, which comes between the first month and the sixth month of life. Then at about two to four years of age, clubbing is noted and shortness of breath during exertion becomes the troublesome symptom. Later on characteristic squatting position occurs and finally in advanced cases, anoxic blue spells occurs. At this stage the child becomes suddenly dyspnoeic and restless. These attacks may last for a few minutes to a few hours and occasionally may be fatal.

Physical Signs:

There is central cyanosis and clubbing of fingers and B.P. is usually normal. Palpation of precordium reveals moderate right ventricular heave, as presence of VSD, ensures equalisation of pressure both ventricles; hence RVH is not too much. If VSD is unusually large, pansystolic murmur is not present.

Systolic thrill is present in 50% of the cases at the left sternal border in the third interspace. A grade II to IV ejection systolic murmur is heard. First sound is normal. There may be an ejection click heard at the second intercostal space. Second sound is usually single which is due to A₂.

Heart size is usually normal. The normal bulge due to pulmonary artery is absent. In the lateral view, right ventricular hypertrophy can be seen. Aortic arch may be right sided in 25% of cases.

Lung fields are too clear due to poor perfusion.

The electrocardiogram is very helpful. It shows right axis deviation and only moderate right ventricular hypertrophy, sometimes rsR’ pattern can be seen.

Echocardiography is very helpful and sometimes it can differentiate conditions like double outlet right ventricle from truncus arteriosus.

Cardiac catheterization shows right ventricular pressure is elevated. There is a fall of pulmonary artery pressure, may be at the valvular level or at the subvalvular level. The level of arterial oxygen is approximately 75 to 85% at rest. This is due to the mixture of venous blood into the arterial, system. The actual amount depends on the magnitude of right to left shunt. Selective right ventriculography is diagnostic.

The prognosis is usually not too good without surgery as most children die young due to cyanotic attack or brain abscess. Other complications include cerebral thrombosis due to polycythaemia, paradoxical emboli (from deep vein thrombus and bacterial endocarditis).

The treatment is surgical, which could be a total correction or initial palliative treatment, followed by total correction at a later date. Palliative treatment includes anastomatic procedures, anastomosis of subclavian to right pulmonary or pulmonary artery and descending aorta (Blalock’s operation). Operation is usually rewarding, though there are some post-operative complications.

3. Double Outlet Right Ventricle:

In this condition, the aorta and pulmonary artery arise from the right ventricle. There is a ventricular septal defect through which the blood from the right ventricle goes into the left ventricle. Double outlet right ventricle (DORV) can be complicated by pulmonary stenosis. Subpulmonic ventricular septal defect with pulmonary stenosis. In addition, there may be transposition of the great arteries as well.

The history and the physical signs are more or less similar to those of tetralogy of Fallot. The echocardiography can differentiate these two conditions while angiocardiographic examination finally determines the nature of the congenital defects.

The prognosis, unless operated upon, is unfavourable.

The treatment is surgical correction, creating an intraventricular channel so that the left ventricle ejects blood through ventricular septal defect into the aorta. The pulmonary obstruction is relieved by either creating a valve conduit or just pulmonary valvotomy.

4. Pulmonary Atresia:

This condition is an extreme form of tetralogy of fallot. In this condition the cyanosis appears earlier than tetralogy of fallot. Symptoms are severe in early infancy. Cardiac failure occurs early. Cardiac enlargement is usual. Second sound is single. Right ventricular hypertrophy is noted.

Treatment is pulmonary valve operation, relief of the outflow tract obstruction by patch graft of various types are indicated.

5. Eisenmenger Syndrome:

In this condition, the blood flow in patients suffering from atrial septal defect, ventricular septal defect, and patent ductus arteriosus is reversed. Instead of the flow from left to right, it becomes from right to left. In patients with atrial septal defect, ventricular septal defect, or patent ductus arteriosus, there is increased blood flow into the pulmonary arterioles which causes pulmonary hypertension due to increased vascular resistance; therefore right ventricular pressure becomes higher than the left causing reversal of the shunt.

Symptoms are dyspnoea, fatigue and failure to thrive and recurrent pneumonia, cyanosis becomes obvious and is quite increasing in severity. Associated features are clubbing and polycythemia. In addition, the physical signs of the underlying disease, atrial septal defect, ventricular septal defect and patent ductus arteriosus are present.

Jugular venous pressure is increased when there is added congestive heart failure or tricuspid insufficiency. Heart size is variable. It could be normal in some cases in ventricular septal defect, but usually enlarged in atrial septal defect and patent ductus arteriosus.

The X-ray confirms previous findings in addition; the pulmonary arteries are seen to be significantly enlarged at the hilar areas and they become diminished in their diameter in their peripheral branches.

The electrocardiogram shows definite right ventricular hypertrophy and strain pattern. The echocardiography shows right ventricular hypertrophy in addition to chamber dilatation and the presence of underlying lesion.

Cardiac catheterization shows redirectional shunt at the site of the defect.

Treatment in this condition is usually medical, once pulmonary hypertension and pulmonary vascular resistance has developed. Surgery is contraindicated.

6. Tricuspid Atresia:

In this condition, the tricuspid valve is not developed. There may be a small dimple at the site of the anatomical tricuspid orifice. Sometimes only a small membrane is present, but there is no communication between the atrium and the right ventricle.

This condition could be associated with transposition or without transposition. Each again could be further sub-classified with having decreased pulmonary flow — (1) Pulmonary atresia and (2) Pulmonary stenosis, or with increased pulmonary flow.

The anatomical configuration of the right atrium is larger and sometimes hypertrophied and the right ventricle may be sometimes rudimentary. There is an atrial septal defect, as well as a small ventricular septal defect in most of the cases, the pulmonary valve may be stenosed or may be atresic.

There may be other associated cardiac abnormalities with tricuspid atresia usually, left superior vena cava entering the coronary sinus, abnormal bands in the left atrium, partial anomalous pulmonary venous drainage, subaortic stenosis or coarctation, etc.

Clinical Manifestations:

Shortness of breath develops early. After infancy, clubbing is a common finding in addition to fatiguability.

The heart may or may not be enlarged. Left ventricle is usually hypertrophied with apical heaving impulse present. There is a systolic ejection murmur audible best at the left sternal border. Second sound being single due to the absence of the pulmonary component.

X-ray chest shows heart is usually normal sized. Cardiac contour is variable, sometimes formed by the right ventricle, sometimes by the left ventricle. The right border of the heart is straight or rounded by the enlarged right atrium. Anterior border of the heart may be normal. The X-ray pictures are very much like that of Tetralogy of Fallot.

Electrocardiogram is highly diagnostic. There is left axis deviation, left ventricular hypertrophy and with an abnormal, tall, spiked P waves.

Echocardiogram is interesting; it shows increased echo refractability in and area which is usually occupied by the tricuspid valve. Certainly, there is no valve demonstrated. The right ventricle is small. Pulmonary artery may be atrophic or may have pulmonary stenosis. It may or may not have any transposition.

Cardiac catheterization may also document immediate visualization of the left atrium from the right atrium and followed by left ventricular filling into the aorta. There is complete absence of the dye into the right ventricle.

The prognosis is usually poor. Many infants die within the first few months of life.

Surgical Treatment:

Fontan operation is advised at the age between eighteen months to five years of age.

7. Transposition of the Two Great Arteries:

This condition accounts for the majority of deaths of infants under the age of one year with cyanotic congenital heart disease. Occurs predominantly in males and a significant number of patients have a family history of diabetes mellitus.

In this condition, the aorta arises from the right ventricle and pulmonary artery arises from the left ventricle. Hence the aorta carries the venous blood to the systemic circulation and the pulmonary artery carries blood back to the lungs; hence the life is impossible if there is no communication through atrial septal defect or ventricular septal defect or patent ductus arteriosus. In the majority, ventricular septal defect is the path of communications between the two chambers.

Transposition of great arteries may have the following associations:

(1) With A.S.D.

(2) With V.S.D.

(3) With large PDA

(4) With Pulmonary stenosis

(5) With tricuspid atresia

Clinical manifestations are predominantly cyanosis, congestive heart failure, and retardation of the growth. Cyanosis seems to appear within ten days of life and become progressively worse. Congestive heart failure is inevitable before six months.

In the way of physical signs, significant cardiomegaly with hyperactive precordium, right ventricular thrust is usual, and first heart sound is sharp. Second heart sound is single, or could be narrowly split. Radiology is very characteristic in transposition of the great arteries. Cardiomegaly, increased pulmonary vasculature and a narrow cardiac base due to super imposition of the two arteries in postero-anterior view may be noted.

The electrocardiogram particularly shows right axis deviation, right ventricular hypertrophy, and frequently P pulmonale. There may also be biventricular hypertrophy or dominance of the left ventricle.

The echocardiographic pictures are also very characteristic. In the short axis view of two dimensional echocardiography, the normal anatomic configuration of the pulmonary artery and the aorta is changed, hence the typical circle and “sausage” is changed into double circles. The aorta may be situated on the right or posterior pulmonary artery vessels may not be side by side, the aorta may even be anterior to the left of the pulmonary artery. This depends upon whether it is levotransposition or dextrotransposition.

Through two dimensional views, the exit of the great vessels can be imaged through the long axis parasternal and apical four chamber views. Bifurcation of the pulmonary artery should be always be determined in order to identify properly the pulmonary artery distinct from the aorta. In the early neonates, when the great suspicion for transposition of the great arteries is there, an echocardiography is a must. It will also show the presence of VSD or ASD or PDA.

Prognosis of this condition is fatal unless treated by surgery. Urgent balloon atrial septostomy should be done in order to establish a mixture of venous and arterial blood.

8. Ebstein’s Disease:

In this condition, there is a downward displacement of the tricuspid valve into the right ventricle. The tricuspid valve, consists of three leaflets, has abnormal anterior leaflet which retains its attachment with the annulus, whereas the septal leaflet and the posterior leaflet were inserted into the wall of the right ventricle. The anterior leaflet is very large and may be incompetent. The right atrium is huge, while the right ventricle is relatively small and hence inadequate in expelling the blood into the lungs.

Symptomatology:

The majority of the patients are asymptomatic or the symptoms are very mild complaining of fatigue or some form of cardiac arrhythmias are the first presenting complaint. This may take paroxysmal tachycardia, usually supraventricular type.

Rarely, depending upon the presence of foramen ovale, there may be right to left shunt with consequent cyanosis.

On examination, usually the venous pressure is normal. Carotid pulsations are normally felt. Heart is quiet. Apex beat can be located outside the midclavicular line. There is systolic murmur present over the anterior chest. Diastolic murmur may also be heard. Sometimes there is a tricuspid opening snap or even a series of systolic ejection clicks are heard. Pansystolic murmur of tricuspid incompetence can also be recorded. Sometimes, in the presence of right bundle branch block, one may hear three distinct components of the first sound.

Second sound is usually single composed of A₂. Sometimes splitting of the second sound can be also present depending upon the conduction defect, such as right bundle branch block, which may cause wide splitting.

Third heart sound, right ventricular type is usually present following the P₂. It may be rather high in pitch resembling an opening snap. Fourth sound is occasionally present. Sometimes diastolic tricuspid murmur following the third heart sound may be heard indicating that it has tight ventricular filling.

Electrocardiogram:

Electrocardiogram shows right bundle branch block, tall P waves, and prolonged PR interval, sometimes the pattern of Wolff Parkinson White Syndrome is present.

X-Ray Chest:

X-ray chest shows cardiomegaly, may be from mild to massive and the pulmonary circulation is usually decreased or it could be normal. Aorta is small.

Echocardiography:

Echocardiography is very characteristic and almost diagnostic and particularly two dimensional echo shows the atrial portion of the right ventricle and unusual position of the tricuspid valve.

Cardiac Catheterization:

Cardiac catheterization is hardly necessary and treatment is usually symptomatic: Occasionally, surgical interference may be indicated, which means some form of tricuspid annularplasty and closure of the atrial septal defect.

9. Truncus Arteriosus:

Definition:

In this condition, there is only one large anterior trunk, which leaves ventricular portion of the heart and then divides to supply the systemic circulation, pulmonary circulation and the coronary circulation. The large majority of the cases, there is ventricular septal defect. As expected, it is a large artery which has four semilunar valves.

Though the semilunar valves may vary from two to six. Truncus arteriosus should be differentiated from pseudo-truncus and from truncus solitarious pulmonaries. In both these conditions, both the aortic and pulmonary trunk emerges from the heart, however, in the former there is pulmonary atresia while in the latter there is aortic atresia.

Associated Cardiac Abnormalities:

Truncus arteriosus communis could be associated with a fair number of other cardiac anomalies. They are persistant left superior vena cava, anomalous origin of left vertebral from aortic arch, origin of right subclavian from descending aorta, total anomalous pulmonary venous return, common atrio-ventricular orifice, dextrocardia, mesocardia tricuspid atresia, etc.

Clinical Manifestation:

Dyspnoea and fatigue are the most common symptoms. Cyanosis is however minimal. The patient may present with heart failure. On examination, the heart usually appears to be enlarged. Precordium is hyperdynamic and there is a systolic ejection murmur present at the left sternal border. The murmur is preceded with a loud ejection click. Second sound is loud and is always single and appears very superficial. A mild diastolic apical rumbling murmur may also be heard.

Electrocardiogram:

Electrocardiogram shows there may be right, left or combined hypertrophy.

X-Ray Chest:

X-ray chest shows cardiac enlargement, prominence of both ventricles and the truncus sometimes produce shadow, which follows the normal course of the ascending aorta and the aortic knob. Associated right aortic arch in 50% of the patients. Pulmonary vascularity is increased in Type I and Type II cases and decreased in the remaining two types.

Echocardiography:

Echocardiography shows the presence of ventricular septal defect, right ventricle independantly overriding of the large trunk, multiple cusps of the truncus could be seen in the short axis view. Mitral aortic continuity is maintained. No pulmonary valve could be seen; sometimes it is difficult to differentiate from pulmonary atresia with ventricular septal defect and severe tetralogy of fallot.

The prognosis is usually bad. The majority of the patients die during the first two years of life.

The treatment is surgical. Initially some surgeons prefer banding of the pulmonary arteries in order to reduce the pulmonary inflow in Type I and Type II cases and later on, radical corrective surgery could be done, which consists of the closure of the ventricular septal defect and the pulmonary arteries are amputated from the truncus and continuities are established between the right ventricle and pulmonary arteries with a valve conduit.

Single Ventricle:

In this condition, the right and left atrium, by means of separate inter-ventricular valves or with common atrio-ventricular valves empty into a single chamber from which the two main arteries, aorta and pulmonary artery arise. This condition could be associated with transposition of great arteries, dextrocardia and pulmonary stenosis.

Presenting feature is usually shortness of breath and fatigue. Clinical examination shows polycythemia and cyanosis. There may be a left ventricular heave, may have a systolic thrill. A systolic ejection murmur is usually loud and the ejection click is heard. Second sound is single and loud.

Echocardiography:

Echocardiography is very characteristic. It shows the two separate atrio-ventricular valves, but there is no inter-ventricular septum. This can be seen very clearly in the four chamber apical view, or in the subcostal four chamber view.

Treatment is essentially surgical and carries a high mortality.

10. Congenital Mitral Stenosis:

This is relatively a rare condition. It may be an isolated condition or it may be associated with lesions such as PDA, aortic stenosis, and coarctation, of the aorta.

Anatomical defect here is the presence of a funnel-shaped mitral valve.

Symptoms usually appear earlier and is characterised by shortness of breath during exertion. There may be some lack of growth and frequent attacks of cough and cold and some children may have obvious episodes of pulmonary edema and congestive heart failure.

The heart is usually enlarged and there may be a diastolic thrill, loud first sound, rumbling diastolic murmur and an opening snap along with typical. Second sound is usually split with normal physiological variations.

Electrocardiogram:

Electrocardiogram shows right ventricle hypertrophy with bifid P wave’s characteristic of left atrial enlargement.

X-Ray:

X-ray shows characteristic left atrial enlargement. Right ventricular enlargement and pulmonary congestion.

Echocardiography:

Echocardiography is very characteristic. It signifies reduction of the mitral valve surface area in the two dimensional echo and associated left atrial enlargement and small left ventricle, right ventricular enlargement.

Prognosis is usually poor. The majority of the children die in the first two years of life. Surgical treatment is only advisable, but the mortality rate is higher than average.

Congenital Mitral Insufficiency:

This condition could be isolated phenomenon or associated with PDA, coarctation of the aorta, ventricular septal defect, or corrected transposition of the great vessels, endocardial fibroelastosis. Mitral incompetence is the integral part of the endocardial cushion defects.

The essential feature is deformed mitral valve. The leaflets are thickened. The attached cords are also deformed, they may be short and may insert in improper places in the cordi. There may be endocardial fibrosis of varying degree present.

The left atrium enlarges significantly. Left ventricle is also hypertrophied and dilated. The pulmonary venous pressure is increased. Finally in late cases, right ventricle and right atrium are enlarged.

Electrocardiogram:

Electrocardiogram shows left axis deviation. Counterclock wise inscription of the QRS complex, biventricular hypertrophy and normal or spiky P waves.

11. Pulmonary Stenosis:

Pulmonary stenosis may present as an isolated anomaly or it may be associated with other congenital diseases. Hence the classification of the pulmonary stenosis is simple unless complicated with other diseases. Pulmonary stenosis can be valvular type when the .stenosis of the valvular level or the infundibular type when the stenosis is at the infundibular level. But sometimes it can be valvular and infundibular.

Pulmonary stenosis could be associated with patent ductus arteriosus, ventricular septal defect, or atrial septal defect. Pulmonary stenosis could also be associated with other rare diseases like tricuspid atresia, transposition of the great arteries, etc.

Hemodynamics:

Because the pulmonary valves are stenosed, either at the valvular level or at the infundibular level, the pressure in the right ventricle is increased. Subsequently, the right ventricle undergoes hypertrophy as a consequence of the increased pressure. Pulmonary artery pressure however is low. Arterial oxygen saturation remains normal.

Clinical Features:

Usually with a mild form of the disease, there are no symptoms. According to the pressure in the right ventricle, the pulmonary stenosis is classified into three types; when the pressure is less than 50 mm, it is called mild, between 50 to 100 mm, it is called moderate; and above 100 mm, it is called severe.

The symptoms depend upon the severity of the lesion and usually manifestation is shortness of breath during exertion. Occasionally there is chest pain, which is sub-sternal and sometimes the patient may have syncopal attacks.

General development is normal. With a mild degree of pulmonary stenosis, the blood pressure and pulse is normal and the only abnormal finding is a loud pulmonary systolic ejection murmur at the left second intercostal space. The heart size is normal.

Electrocardiogram:

Electrocardiogram may be normal or show very early right ventricular strain pattern. In moderate group the symptoms are slightly increased and there are definite electrocardiographic abnormalities present in the form of right ventricle hypertrophy. Here there is not only rough ejection systolic murmur heard at the pulmonary area, but it may be accompanied with a thrill arid the second sound is split with reduced intensity of the pulmonary component. Radiology of chest shows some abnormality, right ventricular hypertrophy and post-stenotic dilatation of the pulmonary artery, if the lesion is of the valvular type.

Echocardiography will show characteristically the dome pulmonary valve which moves during systole and diastole. Similarly echocardiography can demonstrate the infundibular lesion as well. With the recent Doppler technique the severity of stenosis .can be determined by analysing the doppler flow, and gradients can be measured.

In a severe grade of pulmonary stenosis the patient may have cyanosis due to the reduced cardiac output, the venous pressure may be elevated with increased A wave. The right ventricular lift may be palpable. Systolic murmur and thrill is well evident in the pulmonary area. The second sound is split with delay and diminished pulmonary component.

The electrocardiogram definitely reveals significant right ventricular hypertrophy associated with tall P waves.

Radiology shows decreased pulmonary vascularity, in addition to right ventricular hypertrophy. Cardiac size is moderately enlarged. Cardiac catheterization may be indicated and selective right ventriculography also clearly documents the nature of the obstruction and contrast may also be necessary in order exclude the possibility of any shunt.

Course and Prognosis:

The natural course of the disease is usually very slow and the majority of the patients with a mild or moderate disease can lead a normal life and the prognosis in these cases is usually good. In severe cases, symptoms come early. Progressive shortness of breath and fatiguability are the main symptoms. Treatment is surgical depending upon the nature of the lesion; either pulmonary valvotomy or pulmonary valvular plasty is indicated.

12. Pulmonary Valvular Insufficiency:

The patients are usually asymptomatic and the physical findings are similar to aortic insufficiency, only the carotid pulse and the aortic pulse do not show the characteristic water-hammer type of the aortic incompetence. The first sound and seconds are normal followed by low pitched early diastolic murmur, which increases intensity during inspiration.

Radiology:

Radiology of chest shows prominent main pulmonary artery. Electrocardiogram is normal. In severe cases E.C.G. may show right ventricular hypertrophy.

Echocardiography:

Echocardiography does shows abnormality of the pulmonary valve, but with the Doppler studies, pulmonary incompetence can be well demonstrated.

Absence of the pulmonary valve is usually associated with other defects like tetralogy of Fallot and ventricular septal defect.

The pulmonary arteries are widely dilated here. The condition is usually fatal in infancy.

Recently valve conduit is given in this type of patients and after correcting the ventricular septal defect and ventricular stenosis.