Methods have and are being developed, evaluated and applied to more objectively determine and quantify abnormalities of extent and timing of left and right ventricular wall motion and extent of coronary artery stenoses from cineventriculograms and cinearteriograms. The centerline method, developed in this laboratory to quantify regional ventricular wall motion abnormalities, is being applied to determine the extent to which the human left ventricle can compensate by regional hypercontraction for regional hypofunction and maintain global function as determined by the ejection fraction. These methods are also being applied to determine: (1) the effect of thrombolytic therapy in improving regional and global left and right ventricular performance in myocardial infarction, (2) the effect of residual coronary stenosis on regional ventricular performance after thrombolytic therapy in myocardial infarction, (3) regional abnormalities of timing of motion during systole and diastole, the relationship of these abnormalities to global ventricular performance and to conduction defects in the electrocardiogram. Studies are also in progress to determine the prognostic significance for survival of regional contraction abnormalities. The quantitative coronary arteriographic method is being further developed and applied to determine vasomobility responses of coronary arteries and coronary artery stenoses to various drugs and also to reflexes, such as handgrip, which cause coronary artery constriction. The drug studies are providing new knowledge on the mechanism of action of drugs used to treat patients with angina pectoris. These methods are also being used to determine the natural history of coronary atherosclerotic lesions and the effect of serum lipid lowering with colestepol plus niacin or mevinolin and also cholestyramine on the rate of lesion progression. These quantitative techniques are also being used to determine the dynamics of clot lysis in the coronary arteries of patients with acute myocardial infarction who receive thrombolytic therapy. Factors influencing the rate of lysis and rethrombosis following thrombolytic therapy are being identified.
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