Successful cardiac resynchronization therapy by left bundle branch area pacing through a chronically occluded left subclavian system with limited vascular access preventing coronary sinus lead implant.

BACKGROUND

Conventional cardiac resynchronization therapy (CRT) involves implantation of a coronary sinus pacing lead through a delivery sheath, which typically requires a large venous access through a safe sheath of 9 French or greater in size. In patients who have very limited access due to scar tissue from previous implants or critical venous stenosis/closure, such large caliber access may not be available.

METHODS AND

RESULTS

We report a case of CRT procedure in an 84-year-old male with a previous history of ischemic dilated cardiomyopathy (ejection fraction 40%) who was dependent on right ventricular pacing with worsening heart failure symptoms. The patient was incidentally discovered to have chronic total closure (CTO) of the left subclavian vein during the procedure. Although the CTO was crossed by a wire and dilated, the venous access was limited to a 7 French sheath which rendered conventional CRT through coronary sinus lead implant impossible. However, using the left bundle branch area pacing (LBBAP) technique which requires a smaller venous access, we were able to successfully achieve CRT. Postprocedure, the patient's paced QRS duration narrowed from 198 to 130 ms. His heart failure symptoms improved, and ejection fraction increased to 45% one-month after the procedure.

CONCLUSIONS

In patients with vascular access limited to a small caliber sheath not suitable for conventional CRT, LBBAP may help achieve procedural success and improve clinical outcome.