Summary of Aortic Stenosis Aortic Stenosis is narrowing of the aortic valve resulting in increased work of heart. Mid-systolic ejection murmur is heard on auscultation. Exertional dizziness/syncope, dyspnea and angina are classic features. Electrocardiography is gold standard for diagnosis and treatment involves surgical valve repair, placement and medication.
Video: Aortic Stenosis |
The heart has 4 valves:
The Mitral and tricuspid valves are atrioventricular valves meaning they allow blood to move from the atrium to the ventricles of the heart. This occurs with ventricular diastole.
The aortic and pulmonary valve are tricuspid valves which when open allow blood to move to the aorta and pulmonary system respectively. This occurs during ventricular systole when the heart contracts.
All of the heart valves except the mitral valve are usually tricuspid. However, there can be congenital bicuspid valves which can predispose one to valvular disease later on. The heart valves can be heard most prominent in the following regions of the chest
Aortic Stenosis classic triad of signs and symptoms are dizziness/syncope, dyspnoea, angina on exertion.
Cardiovascular Examination
Cardiac Examination findings include parvus and tardus of the carotid artery and mid-systolic ejection murmur heard over the left second intercostal space parasternal. Murmur can radiate to the carotids.
Signs of severity
Think Squatting increases venous return and accentuate the murmur |
Side note - Clinical Auscultation | ||
Murmur | Heart Sound | |
Mitral Stenosis | High pitched early-diastolic murmur | Loud S1 |
Mitral Regurgitation | Pansystolic murmur radiates to the axilla | Soft S1 loud S2 |
Aortic stenosis | Ejection systolic "crescendo decresendo" murmur radiating to the carotids | Soft S2 |
Aortic regurgitation | early diastolic murmur | Soft S2 |
Differential Diagnosis include other causes of mid-systolic murmurs
Cardiac catheterization involves feeding a catheter through the femoral or radial artery towards the ascending aorta. This allows for visualization of the aortic valve. Tranthoracic echocardiogram allows non-invasive visualisation of the heart valve and is gold standard for diagnosis.
ECG changes in Aortic stenosis can include signs of left ventricular hypertyophy, absent Q wave and left ventricular strain (t-wave inversion)
Side Note:![]() |
Diagnosis
The natural history of AS begins with a prolonged asymptomatic period.
Indications for surgery |
Symptomatic |
Critical obstruction based on catheterisatin |
Management of Aortic Stenosis depends on operable and inoperable patients. For symptomatic operable patients, valve replacement/repair is advised. For young patients, mechanical valve is suggested because of durability.
Emergency (unstable)
Complication
Prognosis Mortality in patients with AS dramatically increases after the development of cardiac symptoms. The rate of death is 50% at 2 years for patients with symptomatic disease unless aortic valve replacement is performed promptly.