Pacemaker Lead Perforation during Right Ventricular Outflow Tract Pacing -Importance of Heart Rotation at Pacemaker Implantation

Abstract

A 70 year-old woman underwent a dual-chamber pacemaker implantation for episodes of transient block and syncope. The transitional zone of her ECG was observed between V4 and V5, indicating clockwise rotation. An experienced physician performed the Right Ventricular Outflow Tract (RVOT) pacing using an active fixation lead without any immediate complications. For RVOT pacing, the lead was placed approximately two-thirds of the distance from the apex to the pulmonary valve in the postero-anterior view and pointing towards the septum in the left anterior oblique view. The ECG revealed a narrow QRS (120 msec) and the lead I morphology was minus-plus. Six days post-implant, a pacemaker interrogation revealed ventricular undersensing and loss of capture with high output pacing. Chest computed tomography revealed the left ventricle was displaced to the left and the left-sided angle between the interventricular septum and horizontal axis of the body was reduced to 16°. It confirmed an RV lead perforation through the RVOT, with 1 cm of the lead positioned outside the heart. We performed a surgical repair. Though ECG and x-rays showed septal pacing, we experienced an unusual case of a subacute myocardial perforation caused by an active fixation lead possibly due to heart rotation. The present case report described a patient with a subacute lead perforation and no hemodynamic instability. It is important for the general cardiologist to pay attention to heart rotation. After implantation, symptoms that can suggest a lead perforation, as major signs such as pericardial effusion are not necessarily present. A pacemaker interrogation shows lower impedance, as well as undersensing or failure to capture the involved chamber in suspicious findings.