Coronary Sinus Morphology in Patients With Atrioventricular Junctional Reentry Tachycardia and Other Supraventricular Tachyarrhythmias

BACKGROUND: Coronary sinus access by electrode catheters is easier in patients with atrioventricular junctional reentry tachycardia (AVJRT) than in patients with other supraventricular tachyarrhythmias. The reason for this has not been addressed. METHODS AND RESULTS: The size and shape of the proximal coronary sinus were measured in 15 patients with AVJRT and 14 control subjects after angiographic visualization. Coronary sinus dimensions, morphology, and angle of origin from the right atrium were measured. The proximal coronary sinus in patients with AVJRT was larger than in the control population. The mean ostium diameter was 12.2 +/- 2 mm compared with control dimensions of 8.5 +/- 1.5 mm, P = .00001. At a distance of 5 mm from the ostium, the coronary sinus measured 10.2 +/- 1.8 mm compared with 8.1 +/- 1.9 mm, P = .007. The dilatation persisted 10 mm into the coronary sinus, with a measurement of 9 +/- 1.4 mm compared with 7.6 +/- 2 mm, P = .04. In 73% of AVJRT patients, the proximal coronary sinus had the appearance of a wind sock. This morphology was seen only in 7% of control patients, in whom the coronary sinus was tubular (in 93%). There was considerable interindividual variability in the angle of origin. CONCLUSIONS: The proximal coronary sinus in patients with AVJRT was significantly different from a control population. The ostium was 44% larger and remained more dilated to at least 10 mm from the ostium. The appearance was like a wind sock in AVJRT patients and tubular in the control patients. These findings may have important implications for arrhythmia pathogenesis in such patients.