'Sinus node' dysfunction associated with left atrial isomerism.

Introduction: The eterotaxic syndromes encompass two main anatomic pictures: left and right atrial isomerism. They cause a distortion of the atria anatomy that may involve the conduction tissue. The prognosis is related to the severity of the intracardiac-associated defects.

Case Report: We describe the case of a patient suffering from asymptomatic 'sinus' bradycardia since childhood, who was referred for pacemaker implantation, in which the diagnosis of left atrial isomerism was made.

Conclusion: The present paper may provide new insights on the clinical course of arrhythmic disorders, in particular among patients with congenital heart disease.