Assessment of left ventricular function
Obstructive coronary artery disease may produce abnormalities of left ventricular function which may affect its diastolic properties and/or its systolic function. Left ventricular function is an important determinant of survival and of functional capacity of patients with coronary artery disease and of those undergoing coronary bypass surgery. Thus, a proper assessment of left ventricular function is vital. It is important to evaluate left ventricular properties individually and not to interchange or confuse them. For example, left ventricular ejection fraction is a parameter of systolic function, left ventricular end-diastolic pressure is an indicator of the diastolic properties of the left ventricle, and the two will not necessarily correlate in an individual patient. Thus, the variables that are measured should relate directly to one’s goals.
Precise evaluation of diastolic properties of the left ventricle is difficult in clinical practice because precise assessment of left ventricular compliance necessitates measurements of left ventricular volume frequently during diastole, simultaneous determination of high fidelity left ventricular diastolic pressures, and also of left ventricular wall mass. The clinical value of such detailed determinations is not known and the most helpful information can be obtained by an accurate assessment of left ventricular end-diastolic pressure and volume.
Left ventricular systolic function may be considered in terms of muscle function, regional wall motion function, and pump function. In intact man, assessment of left ventricular muscle function or contractile state is not easy. Velocity of circumferential fiber shortening at peak stress is perhaps the best currently available method for assessing the . . .