A very rare abnormal course of the thoracic venous system: Long journey to the right ventricle

Case report The patient had a history of coronary artery disease postcoronary artery bypass graft and was hospitalized for syncope due to atrial fibrillation with slow ventricular response, and underwent ventricular pacemaker implantation (VVIR mode). Under fluoroscopic guidance, a right ventricular screw-in lead was inserted via the cephalic vein. The course of the pacemaker leads deviated from the normal brachiocephalic pathway and ran dorsally along the left lateral aspect of the thoracic vertebra and across the thoracic vertebra to the right side at T6 level, and then ran to the right atrium via the superior vena cava (SVC), as shown in Figure 1 (A,B). Anomalous communication with the coronary sinus was excluded by placing a lead into the coronary sinus, which was not communicating with the pacemaker lead. Owing to the long course, the standard ventricular leads could not access the right ventricle. So a ventricular lead (TENDRIL ST 1888TC/65cm; St Jude Medical) was fixed with screws at the mid septum. The whole course was confirmed by electrocardiographic-gated 64-slice computed tomographic (CT) angiography with a 3-dimensional reconstruction, which revealed very short left brachiocephalic veins draining downward into the accessory hemiazygos vein (AHAZV) that communicated to the azygos vein (AZV)