Long-term Follow-up of Patients after Ambulatory Electrocardioversion in the Persisting Form of Atrial Fibrillation

Overview

Atrial fibrillation (AF) is one of the most frequent arrhythmias in the population (with a prevalence of 0.4 to 2.0% and incidence as high as 7.2%; with advancing age the incidence rises). It is associated with thromboembolic complications the risk of which increases in conjunction with implementation of cardioversions persisting for more than 48 hours.The objective of our work was to assess whether cardioversion performed in an ambulatory department is sufficiently sage and effective also in patients where AF persists for longer than 48 hours, provided the patients are subjected to examination by oesophageal echocardiography (TEE). From a total number of 195 patients with persisting AF the authors made 174 electrocardioversions in three basic groups. The first group was formed by 57 patients with AF > 48 hours. There electrocardioversion was performed after a four-week preparation with coumadine. The second group was formed by 49 patients with persistence of AF > 48 hours where electrocardioversion was performed immediately after ruling out thrombi by TEE. The third and last group comprised patients with AF < 48 hours where electrocardioversion was performed without delay It proved possible to restore the sinus rhythm in 143 patients (82%) of the whole group whereby it was mot effective in patients with AF < 48 hours where it proved possible to restore the sinus rhythm in 90% patients, followed by the second group with a period of AF > 48 hours, i.e. without anticoagulation preparation (82%). Electroconversion was leas effective in patients with long-term anticoagulation preparation (group 1 where it was restored only in 73% patients).TEE examination revealed an intracavitary thrombus in 19.6% patients with AF > 48 hours and a spontaneous echocontrast was detected in the left atrium in 27.9% patients. During the time of investigation only two thromboembolic complications were recorded (1.1%) always in patients with AF > 48 hours (once without and once with long-term anticoagulation).A relapse of AF was recorded during the average 10-month period of follow-up in 56 patients, i.e. 39%. The only significant factor influencing the effectiveness of performed electroconversion and incidence of relapses of AF was the duration of arrhythmia before cardioversion.It may be concluded that the results obtained in a relatively large group of patients should support early cardioversion also in patients where AF persists for more than 48 hours even without the usual 4-week anticoagulation which protracts the duration of arrhythmia and reduces thus the effectiveness of the cardioversion. The prerequisite is, however, high standard TEE examination and ruling out the presence of thrombi.

Key words:
atrial fibrillation - ambulatory cardioversion - long-term follow-up.