Electrocardiographic features of ventricular pacing lead in the middle cardiac vein vs. right ventricular apex in a patient with persistent left superior vena cava.
A 53-year-old woman with sinus node dysfunction underwent dual-chamber pacemaker implantation through a persistent left superior vena cava draining into the coronary sinus, which was detected at the time of implantation. We managed to fix the ventricular lead in the right ventricular (RV) apex by forming a clockwise loop in the right atrium. Inadvertently, the lead was placed in the middle cardiac vein resembling RV apical position under fluoroscopic guidance. The paced QRS complex showed a pattern of tall R in V(1) through V(3), RS in V(4) through V(5), and QS in V(6). The pacing lead was carefully manipulated back into the RV apex, with the paced QRS complex showing a pattern of right bundle branch block, rR' in V(1) through V(2), and QS in V(3) through V(6). Careful attention to the surface electrocardiogram helps in distinguishing the pacing site even in those patients showing a pseudo-right bundle branch block pattern with RV apical pacing.
Second Section of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital Linkou Medical Center, Chang Gung University College of Medicine, Taoyuan, Taiwan.
Tien-En
TE
Chen
Chun-Chieh
CC
Wang
Oruganti Sai
OS
Satish
Delon
D
Wu
D001146:Arrhythmia, Sinus / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D003331:Coronary Vessels; D004562:Electrocardiography / Q000379:methods*; D004567:Electrodes, Implanted; D005260:Female; D006352:Heart Ventricles; D006801:Humans; D008875:Middle Aged; D019919:Prosthesis Implantation; D014680:Veins