Background: Atresia of the coronary sinus (CS) ostium with retrograde drainage of the cardiac veins via the persistent left superior vena cava (PLSVC) is a rare abnormality and only a few case reports in association with electrophysiological studies have been reported.
Methods: During standard electrophysiological study in three patients with a focal left atrial tachycardia, atrial fibrillation and common type right atrial flutter, the CS could not be cannulated despite several attempts. Assuming an occluded CS ostium we advanced a multipurpose catheter via the right atrium and the right superior vena cava in a PLSVC and performed CS angiography.
Results: CS angiography showed that the CS was occluded in all 3 patients and the PLSVC was used as a drainage route to the superior vena cava. After retrograde placement of a 2.5 Fr nonsteerable diagnostic catheter via the PLSVC in the CS, the intracardiac CS electrogram was recorded. Successful ablation could be performed in all three cases.
Conclusions: The cases highlight the possibility that failure to access the CS during electrophysiological studies may be related to this anomaly and that retrograde cannulation via PLSVC enables the CS access and acquisition of its electrograms.