Congenital Heart Disease

Wikis > General Medicine > Cardiology > Congenital Heart Disease

Congenital Heart Disease

Most present during first year of life, but can be asymptomatic until adult life. More than 50 different defects have been identified.

Heart is formed by 10th foetal week  congenital heart defect developed by then. Most commonly due to maternal rubella infection, alcohol or drug abuse, or exposure to toxins or radiation. Some genetic defects (eg Down syndrome) may cause septal defects.

General clinical features:
• breathlessness, delayed normal growth, cyanosis, digital clubbing, pulmonary hypertension, syncope, may have murmurs
• may be evident at birth – some later

Patent/Persistent ductus arteriosus:
• 10% of all cases of congenital heart disease
• in foetus, before lungs form, blood passes through ductus arteriosus to aorta – should close after birth  some of left ventricular output is recirculated through lungs (amount depends on size of defect)
• if duct is small  no symptoms until older
• if large  growth and development retarded, cardiac failure, dyspnoea, murmur
• surgical closure

Coarctation of the aorta:
• narrowing of lumen in aorta, usually in area where ductus arteriosus joins aorta. M>F. 1/4000 children; 6% of all cases of congenital heart disease; left ventricular pressure and workload are increased; usually asymptomatic in childhood
• clinically – congestive heart failure; may have headache (due to hypertension proximal to coarctation); diminished lower limb circulation  weakness, fatigue, claudication, cramps, weak pulses
• management - surgical

Atrial Septal Defect (ASD):
• 10% of all cases of congenital heart disease. F>M
• characterised by hole between left and right atria  shunting of blood
• result from incomplete formation of septum or incomplete closure of foramen ovale
• clinically – may not have symptoms; dyspnoea, chest infections, cardiac failure, arrhythmias – often not detected until >40 years of age
• management – surgical closure

Ventricular Septal Defect (VSD):
• 30% of all cases of congenital heart disease. 1/500 live births.
• symptoms due to mixing of blood from left and right ventricles due to hole/defect
• clinically – murmur, cardiac failure
• if small  no specific treatment; endocarditis prophylaxis
• if cardiac failure  digoxin and frusemide
• if large  surgical repair

Tetralogy of Fallot:
• 1/2000 live births; 10% of all congenital heart defects
• 4 components – pulmonary stenosis/narrowing, ventricular septal defect, overriding of ventricular defect by the aorta, right ventricular hypertrophy
• due to abnormal embryological development
• most common cause of cyanosis in infancy/newborns  “blue babies”
• bizarre congenital forefoot anomalies can be associated with it (eg fused metatarsals)
• management - surgical

Others:
Aortic valvular stenosis – narrowing of aortic valve; 6% of congenital heart defects; causes ventricular hypertrophy, left heart failure and pulmonary oedema. Symptoms – chest pain, dyspnoea, fatigue, shortness of breath, fainting spells, exercise intolerance.
Pulmonic stenosis – narrowing of pulmonary outflow tract
Atrioventricular canal defect – common in Down syndrome; failure of growth  defects in valves
Tricuspid atresia – opening between right atrium and right ventricle is not patent

Comments are closed.