Sudden, Severe Aortic Regurgitation: Reversal of the Abnormal Hemodynamics by Amyl Nitrite Inhalation

¹ Cardiovascular Unit, Toronto General Hospital; Department of Medicine, University of Toronto, and Department of Medicine, Oshawa General Hospital

The effect of amyl nitrite inhalation on the hemodynamics of sudden severe aortic regurgitation was studied during heart catheterization. At rest the left ventricular diastolic pressure equaled aortic pressure and exceeded left atrial pressure closing the mitral valve prematurely. Amyl nitrite inhalation transiently decreased the left ventricular diastolic pressure to the level of the left atrial pressure by reducing the degree of aortic regurgitation. This demonstrates that the severity of the aortic regurgitation is the major factor responsible for the abnormal hemodynamics observed in this condition.