Effects of diltiazem and esmolol on cycle length and spontaneous conversion of atrial fibrillation.
BACKGROUND
Calcium channel blocking agents have been shown to prolong the duration of atrial fibrillation. This study compared the effects of intravenous diltiazem and esmolol on the cycle length and conversion rate of pacing-induced atrial fibrillation.


RESULTS
In 41 adults without structural heart disease, atrial fibrillation was induced by rapid atrial pacing. After 3 minutes, either diltiazem (n = 13), esmolol (n = 15), or saline (n = 13) was infused. In the diltiazem group, the atrial fibrillation cycle length shortened by a mean of 43 milliseconds and became significantly shorter than in the control group, while the atrial fibrillation cycle length in the esmolol group did not change. Spontaneous termination of atrial fibrillation occurred significantly less often in the diltiazem group (23%) than in the esmolol (67%, P < 0.05) or placebo groups (77%, P = 0.01).


CONCLUSIONS
Intravenous diltiazem shortens the atrial fibrillation cycle length and lowers the probability of spontaneous conversion of recent-onset atrial fibrillation to sinus rhythm. These results suggest that the use of diltiazem for acute rate control may unwittingly prolong the duration of recent-onset atrial fibrillation.
Sticherling
Christian
C
Division of Cardiology, Department of Internal Medicine, University Hospital Benjamin Franklin, Free University of Berlin, Germany.
Tada
Hiroshi
H
Hsu
William
W
Bares
Anton C
AC
Oral
Hakan
H
Pelosi
Frank
F
Knight
Bradley P
BP
Strickberger
S Adam
SA
Morady
Fred
F
D000328:Adult; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000503:physiopathology*; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology* / Q000627:therapeutic use; D004110:Diltiazem / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011412:Propanolamines / Q000494:pharmacology* / Q000627:therapeutic use; D013997:Time Factors
D002121:Calcium Channel Blockers; D011412:Propanolamines; D004110:Diltiazem; C036604:esmolol