Right Ventricular Pacing ... Or is it?

The authors describe a case in which a permanent pacing lead was actively fixated into the middle cardiac vein of the coronary sinus — an infrequent but potentially serious complication of permanent pacemaker lead implantation. Case Report An 84-year-old male presented with a history of ischemic cardiomyopathy (EF 35%), congestive heart failure (CHF), coronary bypass grafting, and non-sustained VT suppressed by TIKOSYN (Pfizer, New York, NY). The patient had a transvenous internal cardiac defibrillator (ICD) system (EnTrust D154ATG, atrial lead CapSureFix model 5076, right ventricular defibrillation lead Sprint Fidelis 6949; Medtronic, Minneapolis, MN) inserted for primary prevention in March 2006 at another institution, which monitored the patient and device post discharge. Out of concern for diminishing R-waves, a 1388T pace/sense lead (St. Jude Medical, St. Paul, MN) was implanted in the right ventricular apex (RVA). The patient returned to the hospital several months post discharge with complaints of chest pain on inspiration and increasing shortness of breath. An echo was done, which showed global systolic dysfunction, an ejection fraction of 45% and a moderate pericardial effusion. Subsequently, a pericardiocentesis was performed, 225 ml of bloody fluid was removed, and a Hemovac drain was placed. The patient was discharged a week later. The patient returned to his local cardiologist and device clinic for ongoing care. In March 2010, the patient presented to the device clinic with complaints of “chest thumping.” The patient was noted to have diaphragmatic stimulation. The right ventricular lead output had adapted to 5.OV at 1.5 ms PW. The lead was reprogrammed to a lesser output with an acceptable safety margin and absence of diaphragmatic stimulation. During the next several months, the patient complained of increasing fatigue and shortness of breath. He presented to our institution in January 2010 for consideration for cardiac resynchronization therapy. The patient stated he was still actively farming, but an increase in symptoms made it difficult to maintain his workload. Upon evaluation, the patient had an EF of 35%, CHF Class III, native QRS of 178 ms, and was on optimal medication regime for congestive heart failure. The patient paced in the ventricle less than 5%. The patient was explained the benefits and risks of an upgrade to a biventricular ICD, and consented to proceed. In the EP lab, the patient was prepped and sedated according to routine procedure. The initial anterioposterior (AP) fluoroscopy view showed presence of a defibrillator in the left prepectoral region, an active fixation pace/sense lead in the right atrial appendage, and a dual coil active fixation defibrillator in the RVA. Initial images were not saved; therefore, all images are during or immediate post procedure. A lead fracture was noted in the pace/sense portion (proximal) of the defibrillator lead (Figure 1), with an active fixation pace/sense lead in the “presumed” RVA (Figure 2). Left anterior oblique (LAO) projection revealed the probability of the St. Jude Medical 1388T lead to be actively fixated in the middle cardiac vein (MCV) of the coronary sinus (Figure 3). Visual inspection of lead placement in the device header revealed the defibrillator coils in the appropriate ports, the Medtronic 5076 lead in the atrial port, and the St. Jude Medical 1388T in the defibrillator lead pace/sense port. The pace/sense portion of the defibrillator lead had been capped. Each lead was tested independently through the analyzer. Pacing the St. Jude Medical 1388T lead resulted in a right bundle branch block (RBBB) morphology (Figure 4) consistent with left ventricular pacing. A venogram was obtained after coronary sinus cannulation, which confirmed the presence of the St. Jude Medical 1388T lead in the MCV of the coronary sinus. A Medtronic Attain Ability® model 4196 lead was positioned in the posterolateral branch of the coronary sinus (Figure 3). This lead was inserted into the left ventricular (LV) port, the St. Jude Medical 1388T lead into the RV port, and the Sprint Fidelis 6949 coils into the appropriate ports of a Medtronic Consulta™ biventricular ICD. The patient was discharged the following day and returned to the office for follow up eight weeks later. He stated that he was feeling less fatigued and short of breath. The device’s heart failure management report showed the patient’s hours of activity per day were increasing and stable fluid status as indicated by thoracic impedance monitoring. Discussion There have been multiple case studies reported in the literature describing the inadvertent cannulation of the coronary sinus during implantation of a temporary transvenous pacing catheter. Fluoroscopic guidance was not utilized due to the patient’s hemodynamically compromised conditions. These cases were associated with clinical sequelae such as diaphragmatic pacing and RBBB configuration pacing.1,2 This report describes a case in which, unintentionally, under fluoroscopic evaluation, a permanent pacing lead was actively fixated into the MCV of the coronary sinus. During the post operative phase, the patient experienced symptoms attributed to pericardial tamponade and diaphragmatic pacing. These presentations were thought to be and treated as isolated events, but in retrospect, were due to active fixation of a permanent pacing lead in the MCV of the coronary sinus. Conclusion This case illustrates an infrequent but potentially serious complication of permanent pacemaker lead implantation. Evaluation of final lead placement in multiple views as well as a high index of suspicion in the presence of RBBB configuration during right ventricular pacing associated with or without diaphragmatic pacing may avert the occurrence of this negative outcome. Editor’s Note: This article underwent peer review by one or more members of EP Lab Digest’s editorial board.