Sick sinus syndrome in a patient with single coronary artery anomaly

Single coronary artery anomaly is very rare. The reported manifestations in clude angina pectoris and congestive heart failure. Here we describe a case of single coronary artery anomaly presenting as sick sinus syndrome, which has no literature precedence. A 47-year-old woman had complained of interm ittent dizziness for years. A Holter electrocardiogram showed sinus bradyca rdia and junctional or ventricular rhythm with a maximal ventricular pause of up to 3.2 seconds. Electrophysiologic study revealed prolonged corrected sinus nodal recovery time. Coronary angiography showed that the left anter ior descending artery had a long course with a side branch originating from the proximal part and coursing anteriorly to the territory of the proximal portion of the right coronary artery. The sinus node is usually supplied b y the sinoatrial branch via the right coronary artery. Aortography showed t hat the right coronary artery ostium was absent. A permanent pacemaker was implantated and the patient was discharged in good condition. The present c ase suggests that coronary artery anomaly may lead to compromised blood sup ply to the sinus node, and hence sick sinus syndrome.