Amiodarone for rapid cardioversion of chronic atrial tachyarrhythmia?

Electrical cardioversion of atrial tachyarrhythmia has disadvantages, such as the need for general anaesthesia, skin burns and thoracic pain. Pharmaco dynamic cardioversion is without these side effects, but the reports of the efficacy of the treatment vary a lot. Amiodarone has been the only drug so far reported to give a combination of high efficacy and low frequency of s erious side effects such as ventricular tachycardia and shock. The purpose of the present study was to assess the effect of amiodarone on chronic atri al tachycardia. Seventeen patients with chronic atrial fibrillation or flut ter were given an oral dose of 30 mg/kg amiodarone. Serial blood tests afte r amiodarone ingestion were taken to document absorption. Patients, who did not convert to sinus rhythm within 24 hr were treated by electrical cardio version. No patients converted pharmacodynamically to sinus rhythm. Twelve patients (71%) reached the recommended serum concentration of amiodarone (2 -2.5 mg/l, median 2.4 mg/l, range 0.96-4.7). The concentration of desethyla miodarone remained low (<0.2 mg/l), and there were no objective or subjecti ve side effects following the treatment. Sixteen patients (94%) were conver ted to sinusrhythm the day after by electrical cardioversion without compli cations. A single high dose of amiodarone is a safe but ineffective method of converting chronic atrial fibrillation and flutter, and may be used as a djuvant therapy in combination with electrical cardioversion.