Long-term carvedilol therapy increases parasympathetic nervous system activity in chronic congestive heart failure.
To determine the effect of beta blockade on parasympathetic nervous system activity, we assessed RR variability during 24-hour Holter monitoring in 10 patients with congestive heart failure before and after 3 to 4 months of treatment with the beta blocker carvedilol. High-frequency power increased from 26 to 64 ms2, root-mean-square of successive differences in RR interval increased from 14.3 to 23.7 ms2, and percentage of absolute differences >50 ms between successive normal RR intervals increased from 0.8% to 4.7%, all p <0.01, indicating a substantial increase in parasympathetic modulation of RR intervals.
Goldsmith
R L
RL
Division of Circulatory Physiology, Columbia University, College of Physicians and Surgeons, New York, New York, USA.
Bigger
J T
JT
Bloomfield
D M
DM
Krum
H
H
Steinman
R C
RC
Sackner-Bernstein
J
J
Packer
M
M
D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D002227:Carbazoles / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D000077261:Carvedilol; D002908:Chronic Disease; D004077:Digoxin / Q000627:therapeutic use; D004562:Electrocardiography / Q000187:drug effects*; D005260:Female; D006333:Heart Failure / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010275:Parasympathetic Nervous System / Q000187:drug effects*; D011412:Propanolamines / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use
D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D002227:Carbazoles; D011412:Propanolamines; D000077261:Carvedilol; D004077:Digoxin