A review of direct current cardioversions for atrial arrhythmia.
The risk of arterial embolism is well recognised following Direct Current Cardioversion (DCC) for atrial fibrillation although the use of prophylactic anticoagulation remains controversial.


OBJECTIVE
To determine the risk of arterial embolism post-cardioversion and which factors predict successful cardioversion and maintenance of sinus rhythm.


METHODS
A retrospective study was carried out of all cardioversions performed for atrial fibrillation and atrial flutter at the Waveney Hospital Ballymena, during 1989-1993. A review of medical records and electrocardiograms was carried out to assess demographic characteristics, co-existent diseases, anticoagulant status, echocardiographic features and characteristics of the arrhythmia. Embolic events in the six weeks post-cardioversion were noted.


RESULTS
The study included 157 cardioversions in 109 patients. The predominant arrhythmia was atrial fibrillation (n = 108, 69%). Three of 109 patients (2.7%) experienced embolic complications, none of whom had anticoagulation prior to the procedure. No risk factors for cerebro-vascular disease or significant valvular heart disease were present. Return to sinus rhythm was achieved in 143 (91%) procedures. Increasing coarseness of atrial fibrillation was associated with a non-significant trend towards successful restoration of sinus rhythm (p = 0.18). Recurrence of the original arrhythmia was predicted by an increase in coarseness of atrial fibrillation (p < 0.05).


CONCLUSIONS
These findings indicate that embolic complications can occur in patients undergoing DCC with normal echocardiographic dimensions, and that prophylactic anticoagulation should be considered in all patients. Coarseness of atrial fibrillation may be used as a guide to predict the chance of successful cardioversion and of the likelihood of maintaining sinus rhythm once this has been achieved.
Johnston
S D
SD
Department of Medicine, Institute of Clinical Science, Royal Victoria Hospital, Belfast.
Trouton
T G
TG
Wilson
C
C
D000328:Adult; D000925:Anticoagulants / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000628:therapy*; D001282:Atrial Flutter / Q000628:therapy*; D016009:Chi-Square Distribution; D004554:Electric Countershock / Q000009:adverse effects*; D004617:Embolism / Q000209:etiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D018709:Statistics, Nonparametric
D000925:Anticoagulants