Introduction

Abstract

The study of cardiac function in a heart totally isolated from the body is required when one tries to relate properties of isolated cardiac muscle to heart function in the intact animal. Due to the fibre arrangement within the ventricular wall, the complexity of the spread of excitation, the presence of valves and the different problems related to relaxation and filling of the heart it is impossible to derive relations between pressure and flow throughout the cardiac cycle directly from length tension relationships which are obtained from studies on trabecula or papillary muscles. An isolated heart preparation is indispensable for the study of drug action on the heart. Only few drugs act solely on the heart, more often the vascular bed is influenced simultaneously and drug action cannot be ascertained due to the complex interaction of heart and vascular system.