Commonest type of congenital heart disease is –
VSD is the commonest CHD.
VSD is the commonest acyanotic CHD.
Acyanotic congenital heart diseases
- Acyanotic heart diseaes may be of two types : -
- Left to right shunts. (ASD, VSD, PDA)
- Obstructive lesions (PS, AS, Coarctation of aorta).
A) Left to right shunts
Patients with left to right shunts have following features: -
- Frequent respiratory tract infection → Because pulmonary circulation is overloaded which may result in pulmonary edema, CHF and infection.
- No cyanosis → Most of the blood is in pulmonary circulation. So there is no impairment in oxygenation of blood.
- Precardial buldge -4 Frequent chest infections with tachypnea causes the soft rib cage being drawn inward at the diaphragmetic attachments of the ribs. This combined with cardioamegaly gives them a precordial buldge.
- Hyperkinetic precordium
- Delayed diastolic murmur in tricuspid or mitral area → Due to increased flow through these areas depending on the type of CHDs.
- Cardiomegaly with plethoric pulmonary vasculature on chest X-ray → Due to increased flow through pulmonary circulation (plethoric lung) there is increased volume overload to left side of heart → Cardiomegaly.
B) Obstructive lesions
- Obstructive congenital diseases have following features.
- Absence offrequent chest infection → Pulmonary circulation is not overloaded.
- Absence of cyanosis → No defect in pulmonary oxygenation and there is no shunt where arterial and venous blood can mix.
- Absence of precordial buldge → There is no chest infection or Cardiomegaly.
- Heaving (forcible) cardiac impulse → Obstructive lesions cause concentric hypertrophy of ventricles that produce forcible contraction.
- Systolic thrill due to systolic ejection murmur → When hypertrophied ventricles forcibly pump the blood through stenotic pulmonary or aortic valve, systolic thrill and systolic ejection murmur are produced.
- Absence of delayed diastolic murmur in mitral or tricuspid area → Blood flow through these area is not increased.
- Presence of delayed corresponding second sound (A2 in AS and P2 in PS) → Because prolonged flow through these area results in delayed closure of that valve.
- Normal sized heart and pulmonary vasculature in chest x-ray → There is concentric hypertrophy, i.e., hypertrophy without dilatation. So, heart size is normal on x-ray.