Introduction: Recently, several studies showed that focal atrial fibrillation (AF) can be initiated by ectopic beats from the vein of Marshall (VOM). However, the incidence and best fluoroscopic views of VOM have never been reported.
Methods and results: 106 patients (Non-AF = 52, AF = 54) underwent balloon-occluded coronary sinus angiography using seven fluoroscopic views (PA, Lateral, RAO 30 degrees, RA 30 degrees + Caudal 20 degrees, LAO 30 degrees, LAO 60 degrees, LAO 60 degrees + Cranial 20 degrees ). The total incidence of VOM was 74.5% (79/106), without significant difference in age (81.1 vs. 71.0%, >65 vs. <or=65 yrs, p = 0.257) and sex (male vs. female = 72.7 vs. 77.5%, p = 0.585). Furthermore, similar incidence of VOM was noted in patients with Non-AF (71.2%) and AF group (77.8%, p = 0.434). The RAO 30 degrees fluoroscopic view can demonstrate all the left atrial veins and VOM. However, only the LAO 30 degrees fluoroscopic view could confirm VOM and differentiate it from left atrial veins (after vs. before junction of coronary sinus and great cardiac vein, respectively).
Conclusion: VOM was equally distributed in patients with different arrhythmias, and the appropriate fluoroscopic view was important for the differential diagnosis of VOM and left atrial veins.