Assessment of regional myocardial performance from biplane coronary cineangiograms

Bifurcations of coronary arteries provide a myriad of natural landmarks on the epicardial surface. With biplane coronary cineangiograms, these bifurcations can be located in space and followed in time. By calculating the spatial distances between bifurcations on successive cine frames, multiple epicardial segment lengths and their dynamic changes during the cardiac cycle can be determined. In 5 animals with epicardial metal markers sutured near the coronary bifurcations, epicardial segment lengths measured from opacified bifurcations correlated closely with those obtained from metal markers (SEE = 2.2%). Epicardial segment lengths were not affected by intracoronary injection of contrast medium in the first 5 to 6 cardiac cycles. Biplane coronary Cineangiograms of 11 patients were analyzed. Measurements of individual segment lengths yielded reproducible curves reflecting various phases of ventricular contraction and filling. These curves allowed quantitation and simultaneous comparison of the onset, duration, extent and rate of segment shortening in multiple and selected areas of the heart. In 5 patients, the extent of shorteing was 1 to 19 percent along the septum, 17 to 27 percent on the free wall and 10 to 15 percent at the base of the left ventricle. Mechanical activation of the left ventricle began from the antereoseptal area at the apex and progressed toward the base and the posterior surface. In 5 of 6 patients with coronary artery disease, localized abnormalities of contraction were found in areas of previous myocardial infarction or at regions supplied by the stenotic arteries. The diseased segments showed either systolic lengthening or marked reduction in rate and extent of shortening. The onset of shortening was frequently delayed. In addition to defining the anatomic details of the coronary circulation, biplane coronary cineangiograms provide a wealth of physiologic information regarding the dynamic changes in geometry, dimensions and movements of the heart. As the first step to utilizing this physiologic information, this study has demonstrated the validity, feasibility and clinical usefulness of this technique in assessing regional myocardial performance in man.