Assessing the Hemodynamic Severity of Acute Aortic Regurgitation Due to Infective Endocarditis

Abstract

Nine patients who underwent aortic-valve replacement for acute aortic regurgitation due to infective endocarditis were studied for clinical features that may be useful in assessing the severity of this condition. The traditional physical signs of a wide pulse pressure were absent. As compared to a group of patients with chronic aortic regurgitation, the mean (plus or minus S.D.) pulse pressure (55 plus or minus 7 vs. 105 plus or minus 22 mm Hg), left ventricular end diastolic volume (146 plus or minus 28 vs. 264 plus or minus 64 ml per square meter) and stroke volume (89 plus or minus 22 vs. 163 plus or minus 57 ml per square meter) were significantly smaller in the acute group (P less than 0.01). Left ventricular pressure exceeded left atrial pressure in late diastole, causing premature closure of the mitral valve, and the degree of early closure reflected the increase in left ventricular end diastolic pressure. Premature closure of the mitral valve was demonstrated by echocardiography in all patients. Those with echocardiographic signs of very early mitral-valve closure have severely volume-overloaded ventricles and are candidates for early valve replacement.

Acute Valvular Regurgitation

“…Impaired forward stroke volume yields a decreased systolic pressure and a narrow pulse pressure. 12,13 Although there is some degree of compensation by a Frank-Starling mechanism, the ventricle is functioning on a steep pressure-volume curve because of the lack of chamber dilation. This contrasts with chronic regurgitation, in which end-diastolic pressures are relatively low, and the additional stroke volume manifests as an increased systolic pressure (Table 2).…”

Interpretation of cardiac pathophysiology from pressure waveform analysis: Aortic regurgitation

“…The immediate and rapid increase in diastolic pressure in the left ventricle with or without a wide aortic pulse pressure is one of several findings which distinguishes acute from chronic aortic regurgitation (see Table II). Early closure of the mitral valve with rapid left ventricular filling limits the increase in pulmonary capillary wedge pressure substantially below left ventricular end-diastolic pressure [8]. The hemodynamic tracings obtained during aortic balloon valvuloplasty, at times, demonstrate the immediate and dramatic results of acute aortic regurgitation [9].…”

Recognition and Treatment of Acute Aortic Regurgitation

“…Factors Acute aortic regurgitation results in a large, rapidly progressive volume overload on a relatively normal left ventricle [1,2,20,21]. The ability of the left ventricle to increase its compliance or distensibility in the acute case is limited; as a result, there is a marked elevation of left ventricular filling pressures, and pulmonary and systemic venous congestion develops rapidly ( [2].…”

“…Used with permission.) increased [21]. Most of the total stroke volume is regurgitated back into the left ventricle during diastole ; therefore, the forward (effective) stroke volume to the body is markedly reduced, and the cardiac output may be severely compromised.…”