Echocardiography of the mitral valve in aortic valve disease.

Ultrasonic echocardiograms from the anterior cusp of the mitral valve have been obtained in 75 patients with aortic regurgitation in whom there was haemodynamic or surgical confirmation, or both, of the state of the mitral valve. Coincident mitral stenosis could be recognized from the echocardiogram in all cases by a slow diastolic closure rate and widening of the echo from the anterior mitral cusp. In many of these patients delayed systolic closure of the mitral valve was also seen. All patients with an Austin Flint murmur had either premature systolic closure of the valve and an accelerated diastolic closure rate or diastolic oscillations of the valve. The amplitude of excursion of the anterior mitral cusp was normal in patients with an Austin Flint murmur and reduced in patients with organic mitral stenosis. It is suggested that the Austin Flint murmur may have two origins. It may be associated with premature mitral valve closure when a short diastolic filling time and a high left atrial pressure are accompanied by turbulent blood flow through the mitral valve, a situation similar to that in mitral stenosis. In patients without heart failure the Austin Flint murmur seems to be associated with rapid diastolic oscillations of the anterior cusp which when present are a diagnostic feature on the echocardiogram of patients with lone aortic regurgitation and which are not seen when there is associated mitral stenosis. Echocardiograms of the mitral valve can therefore be used to differentiate organic from functional mitral diastolic murmurs in patients with aortic regurgitation. The method is very reliable. When heart failure complicates aortic regurgitation echocardiography displays its mechanism. Apart from associated mitral stenosis, aortic regurgitation of recent onset (or exacerbation) can readily be distinguishedfrom chronic aortic regurgitation with heartfailure. The latter is associated with delayed mitral valve opening and with premature closure which is slight and does not precede the P wave of the electrocardiogram. In acute aortic regurgitation the echocardiogram shows the singular combination of delayed diastolic opening together with gross prematurity of closure which often precedes the P wave. The resulting spectacular curtailment of the period when the mitral valve is open has precise diagnostic value. These features also are very reliable.