Clinical case:
A 65 year-old male patient with a prior history of ischemic cardiomyopathy, EF 30%, NYHA class III, long-standing persistent atrial fibrillation, and LBBB (QRS duration 176ms). He underwent initial standard bi-ventricular ICD implantation in 2014. He was found to have only one suitable target coronary sinus branch in the posterior to posterolateral position for left ventricular pacing. However, despite programming changes to allow fusion of intrinsic conduction with the CS lead and implantation of the right ventricular (RV) defibrillation lead into a septal position, the post-op QRS duration continues to be relatively wide (168ms). No significant improvement was observed in the LV systolic function or patient’s clinical heart failure status post implant. Therefore, the patient was brought back to the Ascension Borgess Hospital EP lab for implantation of a LBA pacing lead.
The patient’s left precordium was prepared and draped in usual fashion. The axillary vein was re-accessed through which a deflectable EP catheter was inserted and used to map the distal his bundle position. After successful registration of the distal his bundle location, a Medtronic his-bundle delivery sheath was advanced and placed in the vicinity of the left bundle area defined as an area about 1-1.5 cm distal from the recorded distal his bundle signal, towards the left ventricular apex (figure 2). A Medtronic 3830 his bundle pacing lead was advanced and used to engage the LBA. After multiple attempts to screw the lead deep into the septum, we were unable to correct the underlying LBBB (figure 2). However, simultaneous pacing using the CS (pole 3 to pole 4) and the new lead in the LBA resulted in a narrower paced QRS morphology (figure 2). The new pacing configuration resulted in marked narrowing of the paced QRS to 130ms as well as significantly decreased QRS amplitude on the ECG (figure 3). The newly implanted LBA pacing lead was connected to the atrial port with pacing mode programmed to DDDR using a minimal AV delay at 25ms through the programmer because it is not compatible with the DF-4 right ventricular pacing port (figure 3).
After the successful CRT system revision, the patient’s repeat ECHO two months post procedure showed an increase in EF from 30% to 45%. Patient’s heart failure symptoms improved by one functional class.