Prolonged sinus arrest due to the obstruction of a sinus node branch after percutaneous coronary intervention of the right coronary artery.

Myocardial ischemia due to narrowing of the right coronary artery (RCA) may result in sinus arrhythmias, which usually present as transient sinus bradycardia with no hemodynamic instability. We report a rare case of sinus arrest with hemodynamic instability, which lasted for several months, and was caused by the occlusion of the sinus node (SN) artery following the RCA stenting. A 78-year-old woman with diabetes mellitus, hypertension, and dyslipidemia was referred to our hospital because of chest pain during activity. In her coronary angiogram, severe diffuse stenosis of the RCA was observed and intracoronary imaging using intravascular ultrasound revealed diffuse atherosclerotic plaque lesions with partial calcification and vulnerability. RCA was treated by inserting three zotarolimus-eluting stents. Immediately after these interventions, the SN artery originating from the RCA proximal to the lesion was occluded, which resulted in SN dysfunction. Significant bradycardia was observed on electrocardiogram along with low blood pressure, suggesting sinus arrest. Along with hemodynamic instability, sinus arrest lasted for several months, and permanent pacemaker implantation was needed. The plaque burden should be taken into consideration when choosing the appropriate percutaneous coronary intervention strategy because of the potential complication of sinus arrest after RCA stenting. <