Acute Aortic Regurgitation :  The most dramatic presentation occurs in dissection of the aortic root. Endocarditis of the native or prosthetic aortic valve may also lead to acute regurgitation. The prosthetic valve which is stuck in open or semi open position could also present as acute aortic regurgitation. Iatrogenic cause of acute AR is after balloon valvotonly.

When a large regurgitant volume is suddenly imposed on a normal unprepared left ventricle, it leads to raised left ventricular end diastolic and left atrial pressures. Cardiac output falls and the only compensatory mechanism initially is tachycardia. This will be insufficient and patient presents 'with pulmonary oedema and cardiogenic shock. They require early surgery, as. &at is their only chance. Intra aortic balloon pump is contra indicate4 in the presence of aortic regurgitation.