Assessment of Left Ventricular Function Using an Angiographic Method : PANEL DISCUSSION ON TESTING METHODS FOR CARDIOVASCULAR DIAGNOSIS : Critiques on the Analytical Methods for Cardiac Events

Abstract

Angiographic methods are by far the most frequently used for calculation of left ventricular volume, mass, forces acting within the ventricular wall or for analysis of contractile performance and diastolic property of the overall ventricle, as well as regional myocardial function in the presence of ischemia. A critical review of the theoretical basis and practical methods of calculation of these variables is presented. The left ventricular pressure-volume diagram is constructed which allows for an assessment of the inotropic state of the ventricle from the similar tension-length framework as obtained in the isolated papillary muscle. Computer technology of digital filtering and subtraction provides for an enhancement of the contrast of the ventricular image obtained with minimal doses of contrast medium. On-line methods for edge tracing and subsequent data processing are alleviating much of the tedious and laborious work of manual analysis of angiograms and accuracy of the calculation has been enhanced. Left ventriculography is most useful in diagnosing the presence of abnormal wall motion. Methods of assessing the magnitude and extent of the relative area of localized myocardial dysfunction are discussed. Quantitative information is crucial for evaluating prognosis and determining the application of therapeutic interventions.