ATRIAL-FIBRILLATION AFTER IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR IMPLANTATION

Atrial fibrillation is a reported complication of automatic defibrilla tor implantation. Its incidence, risk factors, time-course, and compli cations have not been well-defined. Accordingly, data from 117 patient s who underwent defibrillator implantation via a thoracotomy (n = 71) or nonthoracotomy (n = 46) approach were reviewed. To identify risk fa ctors, 15 variables of potential predictive value were chosen and anal yzed. Atrial fibrillation developed in 26/117 patients (22%) during th e early postoperative period and all but one of these 26 patients had undergone thoracotomy (P < 0.001). Patients who developed atrial fibri llation tended to be older than those who did not (63 +/- 2 vs 58 +/- 2 years, P = 0.04) and more frequently had a prior history of paroxysm al atrial fibrillation (31% vs 10%, P = 0.02). The were also less like ly to be taking Class I or III antiarrhythmic drugs (1/26 vs 24/91, P = 0.01). By multivariate analysis, operative approach (P < 0.001), the absence of antiarrhythmic drug therapy (P = 0.006), and a prior histo ry of atrial fibrillation (P = 0.003) were significant independent var iables. digoxin neither prevented the occurrence of atrial fibrillatio n nor slowed the maximal ventricular response. The mortality and compl ication rates did not differ between the two groups. The major adverse effect of postimplant atrial fibrillation was automatic defibrillator discharge; six patients received between 1 and 11 discharges for atri al fibrillation with rapid ventricular rates.