The right atrial/transoesophagael approach for conversion of atrial fibrillation: a hybrid method for compromise?

Conversion of atrial fibrillation to normal sinus rhythm should be a highly successful procedure. The method should be safe, take only a few minutes, without the need for general anaesthesia or deep sedation, and on an outpatient basis. Methods of conversion in clinical cardiology do not fulfil these criteria at the present time, as demonstrated by the guidelines of working groups and consensus conferences recommending inhospital use of drugs and/or electrical conversion only and post-cardioversion intensive care observation of patients. Increasing limitations of the resources of health care systems mean that alternative methods for conversion of atrial fibrillation to sinus rhythm are needed. External cardioversion of atrial fibrillation using direct current shock results in a higher conversion rate of sinus rhythm and needs less time in comparison to antiarrhythmic drug conversion. It is today the preferred procedure and is well established in shortterm persistent lone atrial fibrillation or longer-term atrial fibrillation, after a transoesophageal echocardiogram, with warfarin before and after the treatment shock. Recommendations range between low and titrated energy and high power up to 6·0– 6·60 J . kg . Newer guidelines, however, prefer high power initially with an upper limit of 360 J under general anaesthesia to prevent severe discomfort and pain. High power often results in a local cutaneous flush, burning and inflammation but rarely in skeletal and cardiac myocyte enzyme depletion. It is often followed by atrial stunning with the risk of thrombus formation and embolism, but rarely by ventricular stunning with intermittent left heart failure and pulmonary oedema in cases of severe ‘electric intoxication’. Titration of direct current cardioversion power may result in several shocks in cases with a high defibrillation threshold. Therefore a general decrease in power seems mandatory, possibly with sedation instead of general anaesthesia during the procedure. However, atrial stunning and thromboem-