Abstract
With the aims to create a reference population for radionuclide left (ECG-gated) and right (first-pass) ventriculography and to identify independent determinants of normal left and right ventricular (LV; RV) function indices, 50 healthy volunteers aged 21–69 years underwent gamma camera recordings after 30 min of rest (‘R’) and during submaximal semi-supine bicycle exercise (‘E’). From ‘R’ to ‘E’ LV ejection fraction (EF) rose from 0.68 ± 0.04 to 0.78 ± 0.04 (p < 0.0001; Δ LVEF ≥ 0.05 in all). General descriptive data and measures of exercise capacity and of preload and afterload were entered as independent co-variates in a multiple linear regression model. LV peak filling rate (PFR) ‘R’, LV fast filling fraction (FFF) ‘R’, and Δ RVEF decreased significantly with age while time-to-PFR (T-PFR) ‘R’, systole-to-heart cycle duration ratio (SC-ratio) ‘R’, and mean pulmonary transit time (PTT) ‘R’ + ‘E’ increased. Women had shorter time-to-peak ejection rate (T-PER) ‘R’ and higher SC-ratio ‘R’ than men, while obesity was related to higher Δ RVEF and regular weekly exercise to higher FFF ‘E’. Tobacco smoking was of no influence. T-PFR ‘R’ + ‘E’ and SC-ratio ‘E’ decreased with maximal aerobic power while LVEF ‘E’, peak ejection rate ‘E’, and Δ RVEF increased. FFF ‘R’ and RVEF ‘R’ + ‘E’ increased with normalized peak work load, while Δ LVEF increased with watt-exercise time product. Measures of preload and afterload had modulating influences on the LV and RV function indices (‘R’ + ‘E’).
Age exerted a negative influence on LV diastolic function at rest with an accompanying prolongation of pulmonary transit time. Maximal aerobic power and other measures of exercise capacity were directly related to increased left ventricular diastolic function and right ventricular systolic function at rest as well as during exercise, and to left ventricular systolic function during exercise.
