[Anomalous origin of the sinus node artery from the left main trunk: a potential cause of iatrogenic hypokinetic arrhythmia]

The sinus node artery (SNA) arises from the right coronary artery in near 60% of the cases and from the left circumflex artery in the remaining ones. We described the case of a patient in whom the SNA took off from the proximal part of the left main trunk. A 59 year-old male underwent coronary arteriography because of unstable angina. Soon after the incannulation of the left coronary ostium with a 7F catheter critical bradycardia ensued without ECG changes of ischemia. The arrhythmia spontaneously reverted by removing the catheter. Further contrast injections were carried out with a smaller diagnostic catheter (5F); the left main trunk was normal with the SNA arising from the very proximal part of it. It is likely that the heart rate slowing was elicited by a temporary occlusion (and related ischemia) of the anomalous SNA by the diagnostic catheter. This anomaly may therefore provoked heart arrhythmias during diagnostic or interventional procedures.