A 79 year old male with history of sick sinus syndrome associated with frequent syncopal events underwent dual lead pacemaker implantation with atrial and ventricular active fixation leads. Six months post implant he experienced acute inferolateral ST-segment elevation myocardial infarction complicated by cardiogenic shock and underwent successful primary percutaneous revascularization. During diagnostic coronary angiography the angiographic catheters were identified to engage the previously implanted pacemaker leads. Inadvertent positioning of the atrial and ventricular leads via the left subclavian artery to the right coronary cusp and left ventricular apex, respectively, was confirmed with detailed fluoroscopy and selective subclavian angiography. Pacemaker interrogation confirmed lack of atrial capture and normal ventricular sensing and capture thresholds. Following revascularization, the patient had an uneventful hospital course and was discharged on appropriate medical therapy including antithrombotic therapy with aspirin and thienopyridine. Warfarin was not instituted due to persistent anemia and requirement of dual antiplatelet therapy.\nGiven the high risk position of the atrial lead tip in close proximity to the right coronary artery ostium, the patient was electively admitted one month later for transarterial lead removal. Under general anesthesia and in a hybrid operating theater and catheterization laboratory, vascular access was obtained in the right and left femoral arteries and right femoral vein. Prior to systemic anticoagulation, the left subpectoral pocket was opened under sterile conditions, and the subcutaneous tissue was carefully dissected until the leads were visible and freed. Venipuncture was performed using the Seldinger technique, and the left axillary vein was accessed. Two active fixation pacemaker leads were implanted in the right ventricular outflow tract and the right atrial appendage, respectively. Fluoroscopy and aortography were performed demonstrating the dual pacemaker system (). Aortic arch angiography demonstrated a type 1 arch and no significant disease in the origin of the great vessels. Using 5-French diameter, 90 cm length guiding sheaths, the right and left common carotid arterieswere selectively engaged over a guidewire. Carotid angiography revealed nonobstructive disease in the intracranial and extracranial portions bilaterally. Unfractionated heparin was administered to achieve an activated clotting time of approximately 350 seconds. A distal embolic filter wire (Spider, EV3 Inc., Plymouth, MN)was then deployed in the distal segment of the both internal carotid arteries. Selective left subclavian angiography was then performed, confirming the pacemaker leads entry point in the subclavian artery, but no critical subclavian arterial stenosis. Unfractionated heparin was administered to achieve an activated clotting time of approximately 350 seconds.\nStylets were then advanced through the chronic transarterial leads, and after retracting the active fixation mechanism, gentle traction on the ventricular lead enabled withdrawal without requirement of laser extraction. Similarly, the atrial lead was manually withdrawn from the aortic root, and both leads were carefully pulled back until the tips were in close proximity to the insertion site of the subclavian artery. Over an antegradeguidewire, intravascular ultrasound was performed to ensure appropriate sizing for an 8mm x 60 mm self-expanding nitinol covered stent (Viabahn, W.L. Gore, Flagstaff, Arizona) placement. The stent was delivered and positioned between the proximal and distal insertion site margins and deployed immediately as the leads were withdrawn (). Angiography confirmed adequate stent expansion and no contrast extravasation. The distal embolic protection devices were subsequently withdrawn. Following the procedure, the patient remained hemodynamically stable, and recovery was uneventful without neurological or vascular complications.
A 59-year-old man with a history of chronic obstructive pulmonary disease presented to the emergency room with severe sinus bradycardia and hypotension. Due to his history of recurrent dizziness and presyncope, prior work up with Holter cardiac event monitor showed predominant sinus bradycardia with no evidence of chronic incompetence and no clear correlation of his symptoms to the bradycardia episodes. His most recent echocardiogram showed normal left ventricular systolic function and wall motion. Myocardial perfusion study done for recurrent chest pain showed normal myocardial perfusion and normal ejection fraction on Gated SPECT. Tilt table test was markedly abnormal consistent with severe dysautonomia. His baseline blood pressure was 113/70 mmHg, and his HR was 49 beats per minute. Only two minutes into the test, his blood pressure dropped to 60/29 mmHg while his heart rate remained at 47 bpm. The patient was offered pacemaker therapy after his abnormal tilt table test but he refused.\nA few weeks later, the patient presented to the emergency room with syncope. Initial ECG showed severe sinus bradycardia, heart rate in the low 40 s with normal PR interval, and left anterior fascicular block. He was hypotensive and diaphoretic. He denied any chest pain, pressure, or tightness. There were no significant signs of cerebral hypoperfusion. The patient was not on any bradycardia-inducing medications, and initial blood work showed no reversible cause of his severe sinus bradycardia.\nThe patient was started on intravenous fluid hydration, and a bedside echocardiogram was obtained. Echocardiogram showed normal biventricular systolic function and no significant valvular abnormalities. Atropine was given but resulted in minimal, transient improvement in his heart rate to the low 50 s. The systolic blood pressure remained below 80 mmHg. Dopamine followed by norepinephrine drips were administered, and the patient was sent to the electrophysiology laboratory for dual-chamber permanent pacemaker therapy.\nDuring implantation of a permanent pacemaker, the right atrial lead was appropriately placed via the left subclavian vein into the right atrial appendage. However, the ventricular lead was placed via the subclavian artery into the left ventricular cavity. He was admitted to the hospital overnight and a chest X-ray was obtained the next day, showing no evidence of pneumothorax (Figure ). Surprisingly, his ECG showed atrial pacing with long AV delay and intermittent ventricular pacing with the paced ventricular beats showing right bundle branch block morphology contrary to the expected left bundle branch block morphology seen when the lead is inside the right ventricular cavity (Figure ). A limited bedside Echo was obtained that showed the ventricular lead clearly crossing the aortic valve to the left ventricular cavity and fixed into the inferolateral wall of the left ventricle (Figure ). Early recognition of this serious pacemaker implantation complication led to pacemaker revision the same day with extraction of the arterial lead and reinsertion of the ventricular lead via the left subclavian vein into the right ventricular cavity (Figure ). The pacemaker revision went uncomplicated.