PNNL

Abstract

Background: Endoventricular patch plasty (Dor) is used to reduce left ventricular (LV) volume after myocardial infarction (MI) and subsequent LV remodeling. Methods and Results: End-diastolic and end-systolic pressure volume and Starling relationships and 3D myocardial strain was measured 2 weeks before, and 2 and 6 weeks after the Dor procedure. These experimental results were previously reported. The imaging data from one sheep was not adequate. Imaging and strain data obtained from the remaining five animals was used to create animal specific finite element (FE) models. Imaging data from early diasolic filling was used since it was thought to be closest to the unstressed reference configuration. FE models were optimized using 3D strain and used to determine systolic material properties, Tmax,skinned-fiber, and diastolic and systolic stress in remote myocardium and borderzone (BZ). Six weeks after Dor procedure, end-diastolic and end-systolic stress in the BZ were substantially reduced. However, although there was a slight increase in Tmax,skinned-fiber in the BZ near the MI at 6 weeks, the change was not significant. Conclusions: The Dor procedure decreases end-diastolic and end-systolic stress but fails to improve contractility in the infarct BZ. Future work should focus on measures that enhance BZ function alone or in combination with surgical remodeling.