Sudden, severe aortic insufficiency.

THE experimental production of sudden, severe aortic insufficiency causes left ven-tricular diastolic pressure to become markedly elevated so that it exceeds left atrial pressure and results in diastolic closure of the mitral valve.' Ten cases of severe aortic insuffi-ciency have been reported in which left ven-tricular pressure exceeded left atrial pressure during diastole, causing premature mitral valve closure.2 9 In all of these 10 cases the severely elevated left ventricular diastolic pressure equaled the aortic pressure by end-diastole. This latter phenomenon was not observed under experimental conditions.' The etiology of the aortic insufficiency in these 10 cases strongly suggested to Meadows et al.8 that the sudden onset of the lesion and its severity were important factors in the development of these unusual hemodynamic features. In five cases there was a history of bacterial endocarditis,3 6 8 in two the aortic insufficiency developed after surgery for aortic stenosis.3 8 Traumatic rupture of the aortic valve was found in one case,7 the aortic insufficiency developed relatively suddenly in a previously hypertensive patient in another.9 No mention of the valve pathology was available in the tenth case.2 The present report details the clinical and hemodynamic findings in 14 cases of severe aortic insufficiency in whom left ventricular pressure exceeded left atrial pressure during diastole. The severely elevated left ventric-ular diastolic pressure equaled aortic pressure by end-diastole in nine cases (cases 1 to 9) and was less than aortic diastolic pressure in the remaining five (cases 10 to 14). The etiology of the lesion was bacterial endocarditis in 10 instances, prolapse of all three aortic valve leaflets associated with lesions of the ascending aorta in two instances , and rupture of the valve following muscular strain in one instance. The valve pathology in the remaining case is unknown. This experience suggests that the unusual hemodynamic aberrations in these cases was related to the suddenness of onset as well as the severity of the aortic reflux. The poor prognosis attending such aortic valve lesions7' 10-16 renders the prompt recognition of sudden, severe aortic insufficiency of considerable importance. The presence of additional mitral insuffi-ciency in nine of these 14 cases permitted comparison of the effects of this lesion in patients with the previously observed effects of superimposing mitral insufficiency on experimental acute aortic insufficiency. Welsh et al.1 observed that when mitral insufficiency was superimposed on acute aortic insufficiency the left ventricular end-diastolic pressure decreased , whereas …