Little doubt remains that precordial electroshock1,2 has been the most significant and decisive addition to the armamentarium of antiarrhythmic therapy since the introduction of quinidine more than two centuries ago. Most authors agree that synchronized direct-current precordial electroshock is successful in converting approximately 90% of patients with atrial fibrillation to sinus rhythm, regardless of the origin of the heart disease or the duration of atrial fibrillation. In several large series, persistence of sinus rhythm for more than two months has been noted in 33% to 75% of patients.
Most investigators reporting early results have stated that synchronized precordial direct-current shock is safe, simple, and effective therapy for ectopic arrhythmias. However, it was expected that serious complications would occur with its widespread adoption in a variety of clinical situations. For example, electrical conversion has not removed the danger of embolic issues long familiar with quinidine therapy (see p 93 in
COMPLICATIONS OF DIRECT-CURRENT COUNTERSHOCK. JAMA. 1964;190(5):465. doi:10.1001/jama.1964.03070180063013