THROW YOUR LEAD OVER THE OBSTACLE: A CHALLENGING CRT UPGRADING

Abstract

Abstract High percentage of right ventricular pacing could lead to pacing induced cardiomyopathy in a non–negligible proportion of patients. Cardiac resynchronization therapy upgrading could represent an option to improve ventricular function, reducing heart failure hospitalizations. A 82 yo male was admitted to hospital with symptomatic heart failure. He had history of complete AV block treated with dual chamber pacemaker implantation five years earlier following coronary artery bypass graft surgery, bioprosthetic aortic valve replacement and septal myectomy. He had also history of cardiac arrest occurred in the context of acute coronary syndrome treated with PCI so that ICD implant was not considered at that time, and two more HF hospitalizations in previous years. Progressive LVEF decline was documented since PM impantation until last echo showed severe left ventricular dysfunction (EF 20% from baseline EF 60%). The ECG showed sinus rhythm and wide paced QRS (206 ms) with 100% pacing percentage. A CRT device upgrading was planned. Baseline venography initially showed pervious axillary–subclavian left axis, but unfortunately the guidewire encountered a complete occlusion before entering the superior vena cava. Nevertheless, dye contrast injection documented the presence of a proximal collateral branch (fig A) having a vertical course in the thorax and reaching the lateral wall of the left ventricle with an extrapericardic course then entering the right heart through inferior vena cava. Using a IM 5Fr sheath (usually used by interventional cardiologists to cannulate internal mammary artery) we could reach this branch, inserting a guidewire and finally advancing a quadripolar lead (Fig B–C) which reached the lateral left ventricular wall. LV capture was confirmed when pacing from the three proximal poles, while the distal one caused phrenic nerve capture. The quadripolar lead was connected to the LV port of a three chamber PM along with previous implanted leads thus obtaining biventricular pacing. QRS paced was 50 ms shorter than baseline. No peri–procedural complications occurred. Lead–related venous occlusion might represent an obstacle to CRT upgrade requiring high technical expertise. The presence of a complete venous occlusion might cause procedural failure, particularly in hospitals without surgical facility. In this case, the presence of a collateral branch reaching the lateral wall of the left ventricle allowed to successfully complete the CRT upgrade.