Abnormal left ventricular filling in patients with sustained myocardial relaxation: assessment of diastolic parameters using radionuclide angiography and echocardiography.

Parameters of left ventricular filling obtained from time-activity curves of radionuclide angiograms were compared with parameters of myocardial relaxation from digitized M-mode curves of the free wall endocardium in 25 consecutive patients. Eight patients had normal left ventricular systolic and diastolic function. Five patients with low ejection fraction (EF less than 50%) also had abnormal values of peak filling rate (PFR), time to peak filling rate (Tr), and/or time constant of endocardial retraction (Te). Twelve patients with normal EF had three (40%), two (40%), or one (20%) of the diastolic parameters within the pathological range. Tr correlated significantly with Te (r = 0.88, p less than 0.001), and patients with Te prolongation always had high values of Tr. One of the diastolic parameters (PFR) correlated significantly with EF (r = 0.60, p less than 0.01). Parameters of left ventricular filling and myocardial relaxation are thus abnormal in many patients with normal systolic function, indicating that diastolic parameters may be more sensitive to myocardial deterioration.