Περίληψη:
Background: Exercise capacity, assessed by cardiopulmonary exercise
treadmill testing (CPET), does not return to normal following heart
transplantation. This study evaluated the ventilatory response to
exercise and the kinetics of oxygen (O-2) recovery in heart transplant
recipients (HTR) compared to healthy volunteers (HV) and heart failure
patients.
Methods: Eighteen patients with end-stage heart failure (ESHF), 12 with
mild heart failure (MHF) matched for peak oxygen consumption (Vo(2))
with the HTR, 12 HTR and 12 HV underwent CPET for measurements of peak
Vo(2), Vo(2) at anaerobic threshold (AT), first-degree slope of Vo(2)
decline during early recovery (Vo(2)/t-slope), time required for a 50%
fall from peak Vo(2) (T-1/2 of Vo(2)) and the slopes of VE/Vco(2) and
VE/Vo(2).
Results: The MHF and HTR groups had similar ventilatory responses to
exercise and O-2 recovery kinetics. Peak Vo(2) (18.5 +/- 5.7 vs 9.4 +/-
0.9 ml/kg/min, p < 0.001), AT (3.8 +/- 4.8 vs 6.7 +/- 1.8 ml/kg/min, p <
0.001) and Vo(2)/t-slope (0.6 +/- 0.2 vs 0.3 +/- 0.2 liter/min/min, p =
0.055) were higher in the HTR than in the ESHF group. In contrast, HTR
had lower VE/Vco(2)-slope (31.4 +/- 3.8 vs 9.2 +/- 9.9, p = 0.015) and
T-1/2 Vo(2) (1.5 +/- 0.3 vs 2.4 +/- 1.1 minute, p = 0.014) than the ESHF
group. Compared to HV, HTR had lower Vo(2) peak (18.5 +/- 5.7 vs 28.4
+/- 6.9 ml/kg/min, p < 0.001), AT (3.8 +/- 4.8 vs 19.8 +/- 4.5
ml/kg/min, p = 0.04), Vo(2)/t-Slope (0.6 +/- 0.2 vs 1.0 +/- 0.4
liter/min/min, p = 0.005) and steeper VE/Vco(2) slope (31.4 +/- 3.8 vs
23.6 +/- 2.7, p = 0.062). Heart rate deceleration during recovery was
significantly slower in HTR than in all other groups.
Conclusions: Exercise intolerance and delayed O-2 recovery kinetics were
only partially reversed after heart transplantation. This finding
suggests that some of the pathophysiologic mechanisms of heart failure
persist after heart transplantation.
Συγγραφείς:
Nanas, SN
Terrovitis, JV
Charitos, C
Papazachou, O and
Margari, Z
Tsagalou, EP
Kassiotis, C
Tsolakis, E and
Toumanidis, S
Nanas, JN
