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 < 50%) also had abnormal values of peak filling rate (PFR), time to peak filling rate (T_r), and/or time constant of endocardial retraction (T_e). Twelve patients with normal EF had three (40%), two (40%), or one (20%) of the diastolic parameters within the pathological range. T_r correlated significantly with T_e (r=0.88, p<0.001), and patients with T_e prolongation always had high values of T_r. One of the diastolic parameters (PFR) correlated significantly with EF (r=0.60, p<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.