Mechanical Circulatory Support

Abstract

The heart is situated in the middle mediastinum where it is partially overlapped by the neighboring lungs. The weight and size of the heart vary depending on age, sex, body length, epicardial fat, and general nutrition. The coronary arteries are more variable in pattern than any other part of the cardiac anatomy. Applied physiology of cardiac performance was discussed in details.

Cardiomyopathies constitute a group of diseases often of unknown etiology, in which the dominant feature is involvement of the heart muscle itself. A variety of schemes have been proposed for classifying the cardiomyopathies. Cardiomyopathies are classified into three pathophysiologic categories: dilated or congestive, hypertrophic, and restrictive. In an individual patient, features of more than one type of cardiomyopathy can be present.

Intra-aortic balloon is the most widely used form of mechanical circulatory support. A balloon catheter positioned in the descending aorta causes augmentation of diastolic pressure by balloon inflation in diastole and afterload reduction by deflation during isometric contraction phase.

Although it is very beneficial m improving perfusion and reducing myocardial oxygen consumption, yet it is of limited value in severe left ventricular failure. Patients with severe left ventricular failure need greater circulatory support to be able to survive.