Successful Cardiac Resynchronization Therapy Implantation: When to Consider the Middle Cardiac Vein

History

A 58-year-old male office worker with a long-standing history of cardiomyopathy, likely after an episode of viral myocarditis 20 years previously, sought treatment for worsening shortness of breath and functional deterioration. The patient was mildly obese and not in acute respiratory distress. He had a dual-chamber pacing system because of intermittent heart block and symptomatic sinus bradycardia while on medical therapy.

Because of ventricular dysfunction with a left ventricular ejection fraction (LVEF) of 28%, an implantable cardioverter-defibrillator (ICD) was recommended. The patient also had symptomatic heart failure (New York Heart Association [class III]) despite optimal medical therapy and a left bundle branch block with QRS duration of 148 ms. Cardiac resynchronization therapy (CRT) also was recommended.

He was taken to the procedure room at his local facility for upgrade to a CRT defibrillator (CRT-D) system. However, because of inability to place the left ventricular lead, the procedure was abandoned and the patient was referred for consideration of an epicardial system or to reattempt endocardial left ventricular lead and CRT-D placement. The operative note from the outside facility mentioned difficult subclavian venous access and inability to pass a wire beyond approximately 2 cm into the coronary sinus.

Past medical history is significant for intermittent atrial fibrillation, associated with mild symptoms and managed with rate control and anticoagulation.

Current Medications

The patient was taking lisinopril 10 mg twice daily, carvedilol 25 mg three times daily, and digoxin 0.125 mg once daily.

Physical Examination

• BP/HR: 142/78 mm Hg/60 bpm, regular

• Jugular venous pressure: 10 cm H ₂ O

• Heart: Cardiac auscultatory findings significant for murmurs consistent with mild tricuspid and mitral regurgitation and wide splitting of the second heart sound (S ₂ ) with accentuated pulmonary component; no third heart sound (S ₃ ); pacemaker site appeared to be healing normally from the recent procedure; trace pedal edema was noted

Hospital and Procedural Course

After discussing the options of reattempting left ventricular lead placement, surgical epicardial lead placement, and assessment for appropriateness of left ventricular assist device or cardiac transplantation, it was decided to make another attempt at placing the coronary sinus lead before considering the other options. Another attempt at a transvenous approach was favored because of the benefits it offered over epicardial pacing, including lower surgical trauma, potentially more stable pacing electrical thresholds, and greater lead stability.

The patient was brought in the fasting state to the procedure room. An axillary vein puncture was done with contrast venography, and a temporary pacing lead was placed because the patient was pacemaker dependent. The coronary sinus was cannulated without difficulty and balloon venography performed.

Venography findings are shown in Figure 11-1 . As noted in the operative report from the referring institution, a wire would not pass beyond approximately 2 cm into the coronary sinus.

Focused Clinical Questions and Discussion Points