Left ventricular performance following correction of free aortic regurgitation

Left ventricular (LV) myocardial contractility, or inotropic state, was characterized in terms of the instantaneous relations between velocity of circumferential fiber short-ening (V0F), determined cineangiographically, and LV wall tension (hoop stress), calculated from LV dimensions and pressure, in five patients before and 7 to 10 mo after aortic valve replacement for free aortic regurgitation. Preoperatively the cardiac index was reduced or the LV end-diastolic pressure was markedly increased (or both occurred) in four patients, in each of whom depression of inotropic state was docu-mented by a reduced VCF at maximum wall tension, ranging from 0.13 to 1.07 cir-cumferences (circ) /sec (normal,> 1.40 circ/sec) at wall tensions of 318 to 464 g/cM2 (normal, 178 to 417 g/cm2). In one patient in whom LV end-diastolic pressure and cardiac index were normal preoperatively, VCF was 1.66 circ/sec at a maximum ten-sion of 440 g/cm2. Following operation, LV end-diastolic pressure fell in the four patients with depressed inotropic state (average decrease, 23 mm Hg) and cardiac in-dex increased (average increase, 0.93 L/min/m2). However, no change in the tension-velocity relation was observed postoperatively, VCF ranging from 0.27 to 1.14 circ/se