Asynchronous segmental early relaxation of the left ventricle.

Abstract

AbstractAsynchronous left ventricular segmental early relaxation (SER) is an angiographic finding with unclear pathophysiological mechanism. We analyzed 158 consecutive, technically adequate left ventricular cineangiograms of patients undergoing diagnostic cardiac catheterization. Patients with valvular disease, cardiomyopathy, or borderline coronary artery disease (50‐74% lumen diameter reduction) were excluded. The patients were divided according to the presence or absence of coronary artery disease, segmental early relaxation, and left ventricular asynergy. Significant coronary artery disease was detected in 127 patients (80%), segmental early relaxation in 63 (40%), and asynergy in 85 (54%).Forty‐five percent of patients with unobstructed arteries and 38% with significant coronary artery disease exhibited segmental early relaxation. Twenty‐nine percent of patients with coronary artery disease and no asynergy, had segmental early relaxation, while this phenomenon was present in patients with coronary artery disease and asynergy.Since coronary artery disease subgroups are difficult to compare in terms of left ventricular mechanics, two groups of normal patients, 15 with and 14 without segmental early relaxation, were further evaluated: Left ventricular pressure, heart rate, dPdT, left ventricular diastolic volume and wall thickness were not significantly different. Left ventricular end‐systolic volume index was 30.3 ± 4.6 ml/m2 in patients with segmental early relaxation and 22.5 ± 5.1 ml/m2 in those without segmental early relaxation (p < 0.01), while peak wall stress was 332.4 ± 66.6 dynes/cm2 × 103 and 272.2 ± 47.1 dynes/cm2 × 103, respectively (p < 0.02). A third group of patients with segmental early relaxation and coronary artery disease had a repeat left ventricular angiogram after nitroglycerin: Segmental early relaxation disappeared in 12 (group A) and persisted in 4 (group B). After nitroglycerin, end‐systolic volume index decreased by 22% ± 8% in group A and by 1% ± 8% in group B (p < 0.005), while wall stress decreased by 24% ± 12% in group A and did not change in group B (p < 0.01). We conclude that segmental early relaxation, is (1) a very common finding (40% of the entire group); (2) frequent among normals (48%); (3) not a reliable predictor of coronary artery disease; (4) appears to be directly related to end‐systolic volume index and wall stress; (5) disappears following nitroglycerin when this drug decreases end‐systolic volume index and wall stress.