Static Cardiomyoplasty with Synthetic Elastic Net Suppresses Ventricular Dilatation and Dysfunction After Myocardial Infarction in the Rat: An Acute Study

Abstract

Wrapping around the heart (static cardiomyoplasty) may help prevent a failing left ventricle (LV) from dilatation but may also interfere with diastolic relaxation, resulting in restrictive hemodynamics and diastolic heart failure. We developed a synthetic net with a dual elasticity and tested its effect early after induced myocardial infarction (MI) in the rat. In rats undergoing occlusion of the left anterior descending artery (LAD) with and without cardiac wrapping, pressure-volume (PV) relationships were successively analyzed before, after intravenous volume load (saline 1% of body weight over 30 sec), and 10 to 40 minutes after LAD occlusion. In each situation, end-diastolic and end-systolic PV relationships were defined and LV size and function compared under standardized loading conditions. Ischemic increase in LV end-diastolic and end-systolic volumes was suppressed in a similar magnitude in NET with rats, resulting in preserved stroke volume and ejection fraction early after MI. While the presence of the net yielded a significant hemodynamic difference in response to acute volume load before ischemia, the difference was no longer apparent in the ischemic heart after LAD ligation. Static cardiomyoplasty using a synthetic elastic net significantly suppresses ischemic LV dilatation and dysfunction without restriction immediately after MI in the rat. The long-term result is pending. Net material and elasticity needs to be adjusted for optimal girdling effect, or greatest benefits with least functional compromise.