Ambulatory monitoring of left ventricular function during cardiopulmonary exercise tests in normal sedentary subjects.
Ambulatory monitoring (VEST) of left ventricular (LV) function is a useful and accurate method to measure cardiac function during exercise and rest. The aim of this study was to evaluate LV response to exercise in normal sedentary subjects.


METHODS
Ten normal sedentary subjects underwent continuous ambulatory monitoring of LV function by VEST during upright bicycle exercise associated with combined analysis of pulmonary gas exchange. All parameters of LV function were measured in control conditions at rest, at the anaerobic threshold (point of nonlinear increase in ventilation relative to oxygen uptake) and at peak oxygen uptake (peak VO2).


RESULTS
Heart rate and cardiac output significantly increased from control conditions to anaerobic threshold (p < 0.001) and from anaerobic threshold to peak VO2 (p < 0.001). Ejection fraction, end diastolic volume and stroke volume significantly increased from control conditions to anaerobic threshold (p < 0.001), showing no significant change from anaerobic threshold to peak VO2. Finally, end-systolic volume significantly decreased from control conditions to anaerobic threshold (p < 0.001), showing no significant change from anaerobic threshold to peak VO2.


CONCLUSIONS
VEST is particularly useful in the evaluation of cardiac response to exercise in normal sedentary subjects, providing a better understanding of the spectrum of the normal LVEF response to exercise. Our data demonstrate that ejection fraction response to exercise is variable after anaerobic threshold, and a uniform increase is not necessarily expected in normal sedentary subjects.
Imbriaco
M
M
Department of Nuclear Medicine, University Federico II, Napoli, Italy.
Cuocolo
A
A
Pace
L
L
Nappi
A
A
Nicolai
E
E
Cardei
S
S
Morisco
C
C
Romano
M
M
Salvatore
M
M
D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology; D004912:Erythrocytes; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D015637:Gated Blood-Pool Imaging; D006321:Heart / Q000000981:diagnostic imaging*; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D010101:Oxygen Consumption / Q000502:physiology; D011659:Pulmonary Gas Exchange / Q000502:physiology; D015635:Radionuclide Ventriculography / Q000295:instrumentation*; D013670:Sodium Pertechnetate Tc 99m; D013318:Stroke Volume / Q000502:physiology; D013599:Systole / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology*
D013670:Sodium Pertechnetate Tc 99m