Isolated atrial infarction complicated by sick sinus syndrome and atrial fibrillation: a case report

Background: Atrial infarction is a complication of myocardial infarction with ventricular infarction; however, isolated atrial infarction (IAI) has rarely been reported. Herein, we report a case of IAI associated with sick sinus syndrome and atrial fibrillation (AF).

Case summary: An 83-year-old woman was brought to the emergency department with a complaint of general malaise. An electrocardiogram at the time of her arrival showed a junctional rhythm with sinus arrest (SA) at a heart rate of 30 bpm; therefore, temporary pacing was placed urgently, and coronary angiography (CAG) was performed. Coronary angiography showed a solitary occlusion of the sinus node (SN) artery originating from the proximal portion of the right coronary artery. Therefore, revascularization was performed for the occluded SN artery to recover SN function. Bradycardia persisted for several days after the procedure but returned to normal sinus rhythm on day 10. However, during hospitalization, AF attacks frequently appeared with an SA for up to 10 s at AF termination, which is known as the bradycardia-tachycardia syndrome. Catheter ablation (CA) was performed for AF, and no recurrence of AF or bradycardia occurred thereafter. She was discharged without any symptoms.

Discussion: We have experienced a patient who underwent revascularization for the occluded SN artery and CA for paroxysmal AF following IAI, which evaded permanent pacemaker implantation.