The Batista procedure - Theoretical analysis and clinical implications

Background The Batista procedure leads to dramatic early improvement in lef t ventricular function in some patients and a worsening in function in othe rs. The theoretical and actual clinical effects of the procedure on early p ostoperative left ventricular function remain controversial. The purpose of this study is to utilize an appropriate mathematical model to determine th e effects of the Batista procedure on stroke volume and myocardial wall str ess, Our hypothesis is that the preoperative end-systolic stress (sigma (es )) is an important predictor of early postoperative myocardial function aft er this procedure. A corollary is that an index related to sigma (es) may b e useful in selecting patients for this procedure. Methods. An analysis of the Batista procedure is developed, based upon a sp herical membrane model of the ventricle. This model shows how ventricular d ilatation distorts the systolic and diastolic pressure-volume relations. Results, Dilatation initially improves ventricular performance; but further dilatation, beyond a critical value, produces an unstable state with sharp ly falling performance. For a ventricle operating significantly beyond the point of critical dilatation, our theoretical results suggest that the Bati sta procedure not only reduces myocardial stress but may improve stroke vol ume. The end-systolic stress, (sigma (es)) is an indicator of how close a v entricle is to the critical dilatation point. Conclusions. There is a theoretical basis for the Batista procedure. Resect ion of myocardium not only decreases wall stress but may Improve stroke vol ume for sufficiently dilated and depressed ventricles. Patients with marked ly elevated end-systolic stress may benefit most from the Batista procedure .