Article

PURPOSE: To assess whether the same exercise-based inpatient program applied to
patients with normal and reduced left ventricular function (LVF) evokes a similar
cardiac autonomic response after coronary artery bypass graft (CABG). METHOD:
Forty-four patients post-CABG, subgrouped according to normal LVF [LVFN: n = 23;
left ventricular ejection fraction (LVEF) >/= 55%] and reduced LVF (LVFR: n = 21;
LVEF 35-54%), were included. All initiated the exercise protocol on
post-operative day 1 (PO1), following a whole progressive program until
discharge. Cardiac autonomic response was assessed by the indices of heart rate
variability (HRV) at rest and during exercise (extremity range of motion and
ambulation). RESULTS: During ambulation, lower values of HRV indices were found
in the LVFR group compared with the LVFN group [standard deviation of all RR
(STDRR; 6.1 +/- 2.7 versus 8.9 +/- 4.7 ms), baseline width of the RR histogram
(TINN; 30.6 +/- 14.8 versus 45.8 +/- 24.9 ms), SD2 (14.8 +/- 8.0 versus 21.3 +/-
9.0 ms), Shannon entropy (3.6 +/- 0.5 versus 3.9 +/- 0.4) and correlation
dimension (0.08 +/- 0.2 versus 0.2 +/- 0.2)]. Also, when comparing the ambulation
to rest change, lower values were observed in the LVFR group for linear (STDRR,
TINN, RR TRI, rMSSD) and non-linear (SD2 and correlation dimension) HRV indices
(p < 0.05). On PO1, we observed only intra-group differences between rest and
exercise (extremity range of motion), for mean intervals between heart beats and
heart rate. CONCLUSION: For patients with LVFN, the same inpatient exercise
protocol triggered a more attenuated autonomic response compared with patients
with LVFR. These findings have implications as to how exercise should be
prescribed according to LVF in the early stages following recovery from CABG.
Implications for Rehabilitation Exercise-based inpatient program, performed by
post-CABG patients who have normal left ventricular function, triggered a more
attenuated cardiac autonomic response compared with patients with reduced left
ventricular function. Volume of the inpatient exercises should be prescribed
according to the left ventricular function in the early stages following recovery
from CABG.

Langue : ANGLAIS