Predictors of abnormal response of the HRR in the study population.

Data are expressed as mean value ± SD or number (percentage) of patients.
LVEF  =  left ventricular ejection fraction; RBBB  =  right bundle branch block; E =  early diastolic transmitral flow velocity; A =  late transmitral flow velocity; DT  =  deceleration time; ms  =  milliseconds; E/e'  =  ratio of the early diastolic transmitral flow velocity to early diastolic mitral annular velocity; HR  =  heart rate; VO2  =  oxygen uptake; VPB  =  ventricular premature beats.
*defined as more than 7 ventricular premature beats per minute [30].