This study describes the surgical technique and electrophysiologic effects of isolating the right atrium while preserving normal function and continuity of the sinoatrial node with the remainder of the heart. Thirteen adult mongrel dogs underwent normothermic cardiopulmonary bypass. A posterolateral right atriotomy was performed that encircled the upper right atrium but excluded the atrial pacemaker complex. The incision was extended anteromedially to the tricuspid valve anulus just anterior to the membranous interatrial septum and inferiorly just posterior to the os of the coronary sinus and the tricuspid valve anulus. Postoperatively, electrophysiologic data confirmed (1) that the body of the right atrium was electrically isolated from the remainder of the heart, (2) that the sinoatrial node continued to function normally, and (3) that the sinoatrial node remained in continuity with the left atrium and ventricles. Right atrial tachycardia was simulated by rapid right atrial pacing and was confined to the isolated right atrium. Moreover, the simulated tachycardia did not affect normal sinus rhythm or normal atrioventricular conduction. It is concluded that isolation of the right atrium with preservation of normal sinoatrial node function and continuity is feasible. This technique offers and alternative to the current surgical approaches for management of refractory supraventricular tachycardias that arise in the right atrium.