Normal values and reproducibility of left ventricular filling parameters by radionuclide angiography

Background. In physiologic situations age, heart rate (HR) and left ventricular ejection fraction (EF) may influence left ventricular filling rate. In this study, we determined normal values for radionuclide angiography (RNA) derived diastolic filling parameters, the correlations with age, HR and EF and their reproducibility. Methods. The study was performed in 20 patients, 40-76 years old (mean 57), with normal findings at coronary angiography and left ventriculography. The first RNA was performed at rest (RNA1). Then, five minutes bicycle ergometry was performed and the patients were allowed five minutes rest before RNA was repeated (RNA2). From the left ventricular time activity curve we determined peak filling rate (PFR), time to peak filling rate (TPFR) and atrial contribution (AC) to ventricular filling. Results. Values for PFR1 were 2.2 +/- 0.6 EDV/sec (PFR2 2.4 +/- 0.7 EDV/sec, r = 0.82), for TPFR1 198 +/- 22 msec (TPFR2 203 +/- 24 msec, r = 0.45) and for ACl 31 +/- 11% (AC2 31 +/- 10%, r = 0.72). The correlations of PFR and TPFR with age were statistically significant (respectively r = - 0.68 and r = 0.48, P <0.05). PFR was also influenced by HR and EF (resp. r = 0.51 and r = 0.50, P <0.05). TPFR however was not influenced by HR and EF, whereas AC was positively correlated with HR (r = 0.79, P <0.01). Conclusions. Radionuclide angiography is a reliable and reproducible method to assess parameters of diastolic left ventricular filling in individual patients. It may therefore be used to serially follow diastolic function. When used for interindividual comparison the dependency of RNA derived left ventricular filling parameters on age, HR and EF should however be considered.