Effects of amiodarone and diltiazem on persistent atrial fibrillation conversion and recurrence rates: a randomized controlled study.
OBJECTIVE
To assess the effects of amiodarone and diltiazem on atrial fibrillation (AF) induced atrial electrical remodeling and their clinical implications.


METHODS
Persistent AF patients were randomly assigned to three treatment groups over a period from 6 weeks before to 6 weeks after internal cardioversion: group A (35 patients, oral diltiazem), group B (34 patients, oral amiodarone) and group C (37 patients, no antiarrhythmic drugs). Several electrophysiological parameters were assessed 5 min and 24 h after cardioversion.


RESULTS
Compared with controls, group B patients had significantly higher conversion rates (83% vs. 100%, p = 0.041) and a higher probability to maintain sinus rhythm (p = 0.037). Patients of group B had longer fibrillatory cycle length intervals than patients of group A and C (180 +/- 18 ms vs. 161 +/- 17 ms vs. 164 +/- 19 ms, p = 0.001) and longer atrial effective refractory periods (211 +/- 22 ms vs. 198 +/- 16 ms vs. 194 +/- 17 ms, p = 0.003) as assessed 5 min after conversion. Post-conversion density of supraventricular ectopics was significantly lower in group B compared to groups A and C (p = 0.001).


CONCLUSIONS
Oral amiodarone increases conversion rates, prolongs fibrillatory cycle length and atrial effective refractory period and preserves sinus rhythm after cardioversion in persistent AF patients by suppressing the atrial ectopics that trigger AF.
Manios
Emmanuel G
EG
Department of Cardiology, University Hospital of Heraklion, Crete, Greece.
Mavrakis
Hercules E
HE
Kanoupakis
Emmanuel M
EM
Kallergis
Eleftherios M
EM
Dermitzaki
Despina N
DN
Kambouraki
Despina C
DC
Vardas
Panos E
PE
D000368:Aged; D000638:Amiodarone / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000517:prevention & control* / Q000628:therapy*; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D020746:Calcium Channels, L-Type / Q000187:drug effects; D002908:Chronic Disease; D004110:Diltiazem / Q000627:therapeutic use*; D004554:Electric Countershock; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D055502:Secondary Prevention
D000889:Anti-Arrhythmia Agents; D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D004110:Diltiazem; D000638:Amiodarone