Ischemia in aortic stenosis: Due to hypertrophy, the heart requires more blood for oxygenation that may not be possible in severe aortic stenosis resulting in myocardial ischemia even in the absence of coronary artery disease. High left ventricular pressure may compress the coronary arteries in systole and shorten the diastole phase may lead to reduced coronary blood flow manifesting as myocardial ischemia, angina, arrhythmias and left ventricular failure. This ischemia becomes more severe in exercise.
Etiology
- Rheumatic heart disease
- Congenital bicuspid aortic valves
- Calcification of valves in old age
Clinical Features
Aortic Stenosis Symptoms
- Long asymptomatic phase
- Symptomatic aortic stenosis manifests as angina, exercise-induced syncope, exertional dyspnea and ultimately heart failure and sudden death. These symptoms appear when the aortic orifice is reduced to one-third of its normal size.
- On auscultation, there is an ejection systolic murmur at the aortic area.
Investigations
Xray Chest- Chest X-ray may be normal in critical aortic stenosis
- The heart is usually normal in size or slightly enlarged
- Post-stenotic dilatation of ascending aorta on PA view is commonly seen.
ECG
- Left ventricular hypertrophy.
- Left ventricular strain due to pressure overload. Left atrial enlargement.
Echocardiography
- This shows thickened calcified and immobile aortic valve cusp.
- Detects left ventricular hypertrophy, its systolic and diastolic function.
- Droppler echocardiography demonstrates the pressure gradient across the valve and the valve area.
Treatment for Aortic Stenosis
Medical treatment is not effective for aortic stenosis, any patient who develops any of the three symptoms (angina, syncope or heart failure) is the candidate for valve replacement. Surgery is not indicated for asymptomatic patients except those with declining left ventricular function, very severe left ventricular hypertrophy and very high gradient (>80 mmHg) or severely reduced valve area (<0.7 cm2).