Safety of electrical cardioversion in patients with atrial fibrillation.

OBJECTIVES: To determine the incidence of thromboembolic complications after electively performed electrical cardioversion in patients with atrial fibrillation and to assess the clinical variables associated with an increased risk of thromboembolism after cardioversion.

PATIENTS AND METHODS: This is a retrospective analysis of 834 successful electrical cardioversions performed in 717 patients from 1990 through 1994. Outcome measures included embolic complications at 1-month follow-up after cardioversion and logistic regression models to measure the associations among clinical, anticoagulation, and thromboembolic events and to identify independent predictors of these events.

RESULTS: The rate of embolic events after cardioversion was low (0.9%; 95% confidence interval, 0.4%-1.8%). Patients with a therapeutic international normalized ratio had no embolic events. Adequate anticoagulation was independently associated with reduced risk of thromboembolism. Hypertension and diabetes mellitus were independently associated with increased risk of embolization.

CONCLUSION: Adequate anticoagulation reduced the risk of embolization after cardioversion. Diabetes mellitus and hypertension are independently associated with increased risk of embolization early after cardioversion.