AF and His-bundle ablation

Tracing
N° 26
Manufacturer Medtronic Device CRT Field Management of atrial arrhythmias
Patient

69-year-old man implanted with a triple-chamber defibrillator Viva XT CRT-D for valvular cardiomyopathy with permanent AF (no atrial lead implanted) and a narrow QRS; device interrogation performed a few hours after the implant.

Graph and trace
  1. after the implant, rapidly conducted AF, percentage of biventricular pacing at 0% and fast ventricular response (peak HR around 150, 160 bpm);
    The patient underwent bundle of His ablation; device interrogation the day after the ablation procedure;
  2. permanent biventricular pacing (rate responsive function ON); the patient was still lying down in his bed, which explains the absence of heart rate acceleration. 
Comments

Two different types of AF patients benefit from a resynchronization therapy:

  1. patients with slow AF and a bundle branch block;
  2. AF patients with a rapid ventricular response and a narrow or wide QRS. In these latter patients, rate control is essential once the patient is resynchronized. This rate control can be achieved by using rate control medications. However the results are often imperfect. Ablation of the His-bundle is often necessary to enable the high percentages of biventricular pacing essential to the success of this therapy. His ablation is now part of the recommendations of the international guidelines for the treatment of patients with chronic AF and poorly controlled heart rate. After the ablation of the His-bundle, a rate responsive function must be programmed.