Effects of verapamil and metoprolol on recovery from atrial electrical remodeling after cardioversion of long-lasting atrial fibrillation.
The aim of this prospective, randomized study was to investigate the effect of pretreatment with two different intracellular calcium-lowering drugs (verapamil and metoprolol) on recovery from atrial effective refractory period (AERP) shortening after internal electrical cardioversion (EC) of persistent atrial fibrillation (AF) in patients on amiodarone. Twenty-one patients on amiodarone for at least 30 days were referred to our hospital for internal EC of a persistent AF refractory to external EC. They were randomized to receive only amiodarone (group AMI, n=7), or amiodarone and verapamil 240 mg/day (group VER, n=7), or amiodarone and metoprolol 100 mg/day (group MET, n=7). Left AERP was measured 10 min and 24 h after EC. AERP was also determined in 13 controls. The AERP after 10 min was significantly shorter in group AMI (201 (31) ms, P<0.02) and group MET (203 (34) ms, P<0.03) than in controls (249 (45) ms), but not in group VER (237 (51) ms, P=NS). The AERP after 24 h was still significantly shorter in group AMI (204 (38) ms, P<0.04) than in controls, but not in group MET (225 (52) ms, P=NS) or in group VER (290 (36) ms, P=NS). Pretreatment with amiodarone and verapamil prevents AERP shortening, while pretreatment with amiodarone and metoprolol only accelerated AERP recovery.
Bertaglia
Emanuele
E
Dipartimento di Cardiologia, Ospedale Civile, Mirano, Venice, Italy. ulss13mir.card@tin.it
D'Este
Daniele
D
Zerbo
Francesca
F
Michieletto
Marco
M
Pascotto
Pietro
P
D000368:Aged; D000704:Analysis of Variance; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000188:drug therapy* / Q000628:therapy; D016275:Atrial Function / Q000187:drug effects* / Q000502:physiology; D002121:Calcium Channel Blockers / Q000008:administration & dosage*; D015150:Echocardiography, Doppler; D004554:Electric Countershock / Q000379:methods*; D004594:Electrophysiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000008:administration & dosage*; D008875:Middle Aged; D011336:Probability; D011446:Prospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D016896:Treatment Outcome; D020257:Ventricular Remodeling / Q000187:drug effects; D014700:Verapamil / Q000008:administration & dosage*
D002121:Calcium Channel Blockers; D014700:Verapamil; D008790:Metoprolol