THE EFFECTS OF SIMULATED AKINETIC AND DYSKINETIC ANEURYSMS ON LEFT-VENTRICULAR SYSTOLIC FUNCTION - CLINICAL IMPLICATIONS

Objective: Scant attention has been directed towards quantifying the d egree of mechanical disadvantage produced by akinetic and dyskinetic a neurysms. The purpose of this study was to evaluate the mechanical dis advantages of simulated akinetic and dyskinetic aneurysms on left vent ricular function. Methods: hn elaborate experimental apparatus consist ing of a computer-controlled water pressure chamber in which is suspen ded a model rubber ventricle was developed, The system has been shown to reproduce accurately the ventricular and aortic pressures found in vivo. In this study, a procedure was designed to simulate akinetic and dyskinetic aneurysms of various sizes on ventricular function, Result s: The results indicated that an akinetic aneurysm produces little or no mechanical disadvantage with respect to ventricular pressure since systolic paradox is minimal. However, a dyskinetic aneurysm, irrespect ive of size, will usually compromise ventricular function due to parad oxical systolic expansion in the bulging aneurysmic sac. In vivo, othe r factors, such as blood coagulation and rhythm disturbances, may infl uence these results. Conclusions: An akinetic aneurysm causes little o r no mechanical disadvantage while the dyskinetic aneurysm, irrespecti ve of size, will restrict ventricular function. The experimental simul ation system. notwithsanding its limitations, thus provides a unique p rocedure to quantify akinetic and dyskinetic aneurysms. (C) 1997 Elsev ier Science B.V.