International journal of cardiology
-
Randomized Controlled Trial Comparative Study Clinical Trial
Sympathetic inhibition with clonidine improves autonomic balance in congestive heart failure.
In this double-blind, placebo-controlled crossover study, we examined the effect of transdermal clonidine (given for 5 days) on autonomic control in 14 patients with mild to moderate congestive heart failure by heart rate variability analysis. Compared with placebo, clonidine increased the 24-h mean R-R interval from 718+/-110 to 811+/-117 ms (P<0.01), increased the S. D. of all normal RR intervals (SDNN) from 60.8+/-18.5 to 80.9+/-21.4 ms (P<0.01), the S. ⋯ Changes in heart rate variability measures after clonidine administration were positively related to changes in plasma norepinephrine level. These results indicate that suppressing the sympathetic nervous system by clonidine improves autonomic balance in patients with congestive heart failure. But whether such restoration of the autonomic control has a beneficial effect on the long-term management of these patients still needs further investigation.