Heart Diseases

Dr I Brajabihari Singh *

Pain in acute myocardial infarction (front) :: Pix - JHeuser/Wikipedia

Diseases which affect the heart either directly or indirectly are called heart diseases. Heart diseases are of two kinds-
(i) Congenital heart disease
(ii) Acquired heart disease

Congenital heart diseases are found in children because the diseases are already present in children at birth. Sometimes congenital heart diseases are also seen in adults if the diseases are not treated during childhood (treatment is by means of surgical intervention).

Some of common congenital heart diseases are:
(i) Atrial septal defect- a hole in the septum which separates the two atrial chambers, i.e right and left atria (ASD)
(ii) Ventricular septal defect- a hole in the ventricular septum, i.e the septum that separates right and left ventricles (VSD)
(iii) Pulmonary stenasis
(iv) Co-aretation of aorta
(v) Fellot's Tetratogy- a disease caused by a combination of four conditions-
(a) Pulmonary stenosis
(b) Ventricular septal defect
(c) Right ventricular hypertrophy
(d) Overriding of the aorta
(vi) Cardiomyopathy

There is bluish discolouration of the lips, tongue, nail beds and conjunctiva and clubbing of nail beds in Fellot's Trtralogy. The common symtoms are tiredness, fatigue (the child cannot play like normal children), breathlessness-difficulty in breathing, and repeated cough due to chest infection.

Congenital heart diseases are diagnosed by the help of chest x-ray, ECG- electro cardiogram, Echo-cardiography and catherisation of the heart. Congenital heart diseases are treated by surgical correction of the defect in the heart. No medicine can cure congenital heart diseases except to give symptomatic relief of cough and respiratory distress for sometime.

Complications: If congenital heart diseases are treated in the right time during childhood, there will be stunted growth (retardation of growth) and mental retardation. One uncommon congenital heart disease is complete heart block which is present from birth.

Acquired heart diseases

Most of the heart diseases are acquired in nature. Common heart diseases are:
(i) coronary heart disease-myocardial infection-heart attack
(ii) Rheumatic heart disease-where heart valves are damaged by bacterial infection of the heart valves
(iii) Valerelar diseases are caused by damage of the heart valves during myocardial infection, thyrotoxicosis, hypertension, chronic bronchitis and emphysema.
(iv) Heart failure-failure of the heart to pump out blood adequately to maintain proper circulation of all vital organs. Weakness of the heart muscleeither due to hypertrophy or dilation of the ventricular muscles causes heart failure.
(v) Cor-pulmonale: heart failure resulting from right ventricular and right atrial hypertrophy from right ventricular and right atrial hypertrophy is called cor-pulmonale. This is caused by chronic bronchitis and emphysema.

Rheumatic heart diseases

This condition is caused by infection of the heart valves by a group of bacteria known as streptococcus haemolyticus. If it affects the mitral valves it is called either mitral stenosis (narrowing of the mitral valve due to scarring of valves or mitral regurgitation (mitral incompetence) due to dilation of the valve area.

When the infection affects aortic valves- it is called either aortic stenosis (due to narrowing of the valve caused by scarring of the valves and aortic regurgitation due to dilation of the valve area. Both aortic stenosis and aortic regurgitation cause left ventricular hypertrophy. This causes chest pain and breathlessness (shortness of breath).

If untreated it leads to left ventricular failure-heart failure, swelling of feet and legs (oedema). Mitral stenosis causes left atrial hypertrophy-left atrial enlargement.

This also causes left ventricular failure due to congestion of the lungs (accumulation of water in the lungs). Mitral regurgitation causes left ventricular hypertrophy (enlargement) which leads to heart failure if not treated peoperly. As mentioned earlier, all valve diseases cause heart failure-difficulty in breathing, swelling of feet and legs (oedema) and repeated chest infection (cough).

Valve diseases are diagnosed by the presence of two types of murmur, i.e diastolic murmur and systolic murmurs. Diastolic murmurs are produced by turbulent blood flow through the valves and systolic murmurs are produced by obstruction of blood flow through the valves. Mitral stenosis produces mid diastolic rumbling murmur (the sound like rumbling of clouds) and mitral regurgitation produces systolic murmur. But aortic stenosis produces systolic murmur and aotic regurgitation causes disatolic murmur.

Pulmonary stenosis is generally congenital disease But it can also be acquired disease caused by haemolytic streptococeal infection. Pulmonary stenosis produces systolic murmur. Likewise ASD and VSD produce systolic murmurs.

* Rheumatic fever is manifested by moderate rise in temperature, severe joint pain especially in knee and ankle etc.