Isolated perfused working heart preparation for in vitro biomechanical studies

Abstract

The isolated perfused working heart preparation has been an established method of investigation for larger animals. However, because of technical, economic and ethical issues, this methodology needs to be extended for use on mouse heart. Owing to their very small size, rapid heart rate, and different physiology, it was a challenge to modify this technique for mice. Increased evidence for the role of biomechanics in altered physiological states like cardiomyopathies have inspired the extension of using such a highly specialized technique for accessing biomechanical properties of normal (disease free) and diseased myocardium. A possible correlation can be shown using models of strain pattern in normal (disease free) as well as genetically engineered diseased states. In this study, one of the simplest biomechanical parameters, fractional shortening of left ventricular external diameter was computed. The preliminary findings of this in vitro mode of study were then compared to data from an established in vivo method of investigation, 2-D echocardiography. Using fractional shortening, a dimensionless property yielded a very close match, thereby establishing the efficacy of the system.