Effect of oral L-type calcium channel blocker on repetitive paroxysmal atrial fibrillation: spectral analysis of fibrillation waves in the Holter monitoring.
OBJECTIVE
The electrical remodelling is considered to play a role in promoting arrhythmogenic substrate of atrial fibrillation (AF), and intracellular calcium overload may play a key role, especially in its early phase. The effect of oral verapamil on repetitive paroxysmal AF (PAF) was evaluated in clinical cases.


RESULTS
Thirty-five patients with repetitive PAF (total PAF duration >2/24 h) were divided into two groups with and without verapamil administration (240 mg/day) and they were followed-up for 12 months. Before and after the follow-up period, 24 h Holter ECG was recorded. In each Holter recording, total PAF duration and the longest PAF duration was evaluated and spectral analysis was performed for fibrillation waves in PAF episodes to evaluate the fibrillatory frequency. Total PAF duration was prolonged by 45 +/- 79 min in the control group (n = 18) whereas shortened by 25 +/- 55 min in the verapamil group (n = 17, P = 0.005). The fibrillatory frequency was increased from 5.66 +/- 1.05 to 6.73 +/- 1.02 Hz in the control group and was unchanged in the verapamil group. There was inverse relationship between Deltatotal PAF duration and Deltafibrillatory frequency (P = 0.0002).


CONCLUSIONS
Verapamil prevented the increase in fibrillatory frequency in PAF patients in relatively long-term observation. Verapamil might be effective for prevention of the electrophysiological change and increase in PAF episodes at least in specific type of PAF cases.
Niwano
Shinichi
S
Department of Cardio-angiology, Kitasato University School of Medicine, 1-15-1 Kitasato, Sagamihara City, Kanagawa 228-8555, Japan. shniwano@med.kitasato-u.ac.jp
Fukaya
Hidehira
H
Sasaki
Takeshi
T
Hatakeyama
Yuko
Y
Fujiki
Akira
A
Izumi
Tohru
T
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000503:physiopathology; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D018450:Disease Progression; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D055502:Secondary Prevention; D013057:Spectrum Analysis; D014700:Verapamil / Q000627:therapeutic use*
D002121:Calcium Channel Blockers; D014700:Verapamil