Hemodynamic Changes Following Correction of Severe Aortic Stenosis Using the Cutter-Smeloff Prosthesis

Abstract

Twelve patients with pure or dominant stenosis were studied before and after aortic valve replacement (Cutter-Smeloff). The changes in cardiac output and A-V O2 difference were small and insignificant, but exercise stroke volume increased from 72 to 96 ml after the surgery. The aortic peak systolic gradient was 92 +/- 29 mm Hg before and 4 +/- 9.8 mm Hg after surgery. The PA wedge pressure, taken as a measure of the LV diastolic pressure, decreased from 18 mm Hg to 12 mm Hg at rest and 30 mm Hg to 16 mm Hg on exercise. The PA pressures also decreased from 37/18 (mean, 26) to 28/11 (17) mm Hg at rest, and 61/31 (43) to 41/17 (27) mm Hg on exercise, but the PA and PA wedge pressures maintained their tendency to increase in a linear manner with oxygen consumption (Vo2) on exercise after surgery. As a result of decreased wedge pressure, the pulmonary vascular resistance also decreased significantly afterward. The adequacy of cardiac output at rest and on exercise expressed by cardiac output as the linear function of Vo2 improved toward the normal (values before operation, CO = 2.78 + 0.0069 Vo2, r = 0.84; after operation, CO = 3.80 + 0.0062 Vo2, r = 0.91). The exercise factor (delta CO/delta Vo2) or the regression coefficient, however, was similar before and after surgery. The hemodynamic result was satisfactory although some abnormalities of the left ventricular function persisted after operation.

Observed change in peak oxygen consumption after aortic valve replacement and its predictors

“…Exclusion of patients with such conditions (or pausing β-blockers) might lead to clearer results with regard to the outcome of AVR, but this may lead to a biased result with regard to the outcome of AVR in patients in the daily practice. The higher age compared with other studies 2 3 18 27 28 in our study group may also affect outcome, but it is a negative indicator of selection, as also expressed by the comparable age distribution in our study and reference groups.…”

“…The literature on pVO 2 including the change in pVO 2 and predictors of pVO 2 after AVR is sparse. Lee et al 18 found a non-statistically significant mean 12% relative increase in pVO 2 after AVR in 11 severely symptomatic younger patients. 18 Munt et al 2 found no improvement in mean exercise capacity by conventional exercise by testing 34 patients who were initially followed for asymptomatic aortic stenosis and later had AVRs, even though these patients on average improved in resting left ventricular systolic and diastolic function.…”

Standard versus Hemodynamic Plus 19-mm St Jude Medical aortic valves

“…9,20 In the early decades of cardiac operations, hemodynamic evaluation of mechanical aortic prostheses was almost impossible. [21][22][23] Surgeons used to evaluate transprosthetic gradients intraoperatively.…”

Improved Exercise Tolerance, Oxygen Delivery, and Oxygen Utilization After Transcatheter Aortic Valve Implantation for Severe Aortic Stenosis

“…In the early seventies, Lee et al reported similar systemic hemodynamic improvements with reduced ventricular preload that closely matched the exercise-induced increase in oxygen consumption in 12 patients, 3 to 6 months following surgical aortic valve replacement. 11 As a maximal cardiopulmonary exercise test was deemed inappropriate and potentially dangerous in elderly patients with severe symptomatic AS, 12 we performed a submaximal bicycle exercise test that was safely conducted in all patients. As it integrates cardiopulmonary and musculoskeletal systems functioning, this test appears suitable for baseline screening, follow-up assessment, and research purposes, particularly among frail subjects.…”