title: Clinical characteristics of left ventricular pressure decline during isovolumic relaxation in normal and diseased hearts.
abstract: To compare two expressions of the time constant for ventricular relaxation, 39 patients with various heart diseases (six normal, six angina pectoris [AP], 13 myocardial infarction [MI], eight hypertrophic cardiomyopathy [HCM], and six congestive cardiomyopathy [CCM]) were studied. One time constant was obtained by the method of Weiss et al. (T1) and the other was the ratio of left ventricular pressure at peak (-) dP/dt (Pm) to peak (-) dP/dt (T2). The deviation of T2 from T1 was expressed as 100 X (T2 - T1)/T1 (delta %). In normal subjects, T1 was nearly equal to T2 (32 +/- 3 and 32 +/- 6 msec, respectively), resulting in a low value of delta (-1 +/- 9). However, delta values in AP (20 +/- 23, p less than 0.05), MI (24 +/- 26, p less than 0.05), HCM (37 +/- 21, p less than 0.001), and CCM (46 +/- 24, p less than 0.001) were significantly higher than in normal subjects. Thus T1, T2, or delta separated the patient groups from the control subjects, and there were significant differences between T1 and T2 among the types of heart disease.
mesh_terms: D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000503:physiopathology; D001794:Blood Pressure; D006328:Cardiac Catheterization; D009202:Cardiomyopathies / Q000503:physiopathology; D002312:Cardiomyopathy, Hypertrophic / Q000503:physiopathology; D003329:Coronary Vasospasm / Q000503:physiopathology; D006331:Heart Diseases / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D008875:Middle Aged; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000503:physiopathology; D013997:Time Factors; D016276:Ventricular Function