Assessment of cardiac function by right and left ventricular peak to peak time corrected by heart rate

Peak to peak time (PPT) of right and left ventricular time-activity curves was measured by radionuclide angiocardiography to assess cardiac function. PPT was correlated well with heart rate (HR) in 45 subjects with normal cardiac function (r = -0.754). And shortening of PPT was observed in Atropin iv. injection or in increasing rate in pacemaker patients PPT corrected by HR (cPPT) was derived by rotation of the regression equation relating the variables: cPPT = PPT + 0.085 x HR - 5.8. The relationship between cPPT and the age (r = 0.195), sex and body surface area (-0.130) was not significant. CPPTs of 64 patients with various heart disease were prolonged according to the cardiac function grading by NYHA criteria. In the patients with mitral valvular disease, the prolongation was more remarkable, and there was a statistically significant difference against with old myocardial infarction or aortic valvular disease. A relatively good correlation was found between cPPT and other cardiac indices obtained by the same firstpass data of radionuclide angiocardiography: LVEF (r = -0.779), RVEF (-0.518) and cardiac index (-0.457). It is concluded that to apply as an index for assessing cardiac function, circulation time should be corrected by heart rate, and that corrected peak to peak time obtained by radionuclide angiocardiography is useful to evaluate cardiac function. (author)