Acquired leaflet changes from rheumatic fever or degenerative changes.
Hemodynamics
The pressure gradient and velocity of blood flow across the valve are both inversely related to the valve's orifice size and directly proportional to the stroke volume.
Left ventricular work is directly related to the pressure gradient and stroke volume.
Altered arterial pulse – slow rising secondary to the reduced valve orifice and rate of ejection of blood.
An abnormal and turbulent blood flow pattern is present in the ascending aorta.
A systolic murmur beginning after S1. Duration of the murmur and the time to peak intensity are proportional to the pressure gradient.
Aortic insufficiency (regurgitation)
Etiology
Rheumatic fever, congenital abnormalities of the leaflets, inflammatory diseases affecting the valve and/or aorta, aortic root dilatation, aortic aneurysms, infective endocarditis, trauma.
Hemodynamics
The regurgitating blood leads to a volume overload of the left ventricle and an increased stroke work.
Widened arterial pulse pressure occurs because of both the increased stroke volume and the fall in arterial diastolic pressure as blood regurgitates into the left ventricle.
Compensatory changes
Left ventricular dilatation and hypertrophy.
Dilatation of ascending aorta.
Decrease in systemic vascular resistance.
Clinical features
Dyspnea, heart failure, angina.
Multiple signs of widened arterial pulse pressure.
Dilated left ventricle
Decrescendo diastolic murmur beginning with A2, systolic ejection murmur from the large stroke volume through an abnormal valve, and an "Austin-Flint" murmur which is a low frequency diastolic rumble related to turbulent flow from the regurgitation flow and mitral inflow interacting.
Mitral stenosis (obstruction of the mitral valve)
Etiology
Rheumatic fever, atrial myxoma (rare), malfunction of an artificial valve.
Hemodynamics
Increased left atrial pressure with consequent increases in pulmonary venous, pulmonary capillary, and pulmonary arterial pressures.
Decreased stroke volume.
Increased velocity of flow in diastole across the stenotic orifice.
Compensatory changes
Left atrial dilatation and hypertrophy.
Right ventricular hypertrophy secondary to pulmonary hypertension.
Enlarged and hyperdynamic left ventricle, usually a pansystolic (holosystolic) murmur, prominent S3 when there is significant regurgitation. Short, low frequency murmur after S3.