LEFT-VENTRICULAR FUNCTION DURING EXERCISE TESTING AND TRAINING

Left ventricular function (LVEF) deteriorates during incremental exerc ise (GXT) in patients with ischemia (+ISCH). Left ventricular (LV) fun ctional response during steady-state exercise, typical of that used in exercise training, are unknown. We compared LVEF in patients with doc umented coronary heart disease (FHD) who either had (+) or did not hav e (-) ISCH, and in healthy Volunteers (CONTROL) during GXT and steady state. First pass RNA was performed during upright cycle GXT at rest ( R), at the ventilatory threshold (VT), and at maximal exercise (Max); and during steady state at the workload associated with VT after 10, 2 0, and 30 min of exercise. RNA allowed measurement of ejection fractio n (EF) and wall motion (WM); ISCH was mild, angina being relieved by m omentary reductions in workload during steady state. Although +ISCH de monstrated the expected deterioration in LV function during GXT (decre ased EF, abnormal WM)(EF = 58 to 56 to 54%), there was no evidence for progressive deterioration of LV function during steady state despite the presence of mild ISCH (56 to 56 to 54 to 54%). In -ISCH and CONTRO L there were normal responses of EF during GXT (43 to 51 to 51% and 59 to 65 to 61%) and steady state (43 to 51 to 53 to 51% and 59 to 65 to 68 to 69%). We conclude that mild ischemia may be tolerated during st eady-state exercise at levels consistent with exercise training withou t progressive deterioration of LV function.