Atrial fibrillation burden during the post-implant period after CRT using device-based diagnostics

Aims: Cardiac resynchronization therapy (CRT) is increasingly used in congestive heart failure (CHF) patients (with cardiac dyssynchrony). In addition to delivering therapy, CRT devices offer a variety of diagnostic tools for continuous long-term monitoring of clinically relevant information (i.e., occurrence and duration of arrhythmia episodes). Methods and Results: Eighty-four patients with drug-refractory CHF in NYHA-class II-IV received a CRT device. The response to CRT was assessed by determining NYHA class at baseline and at 3 months follow-up. Atrial fibrillation (AF) burden (defined as time of AF per day) was continuously measured by the device. A significant gradual reduction of AF burden (from 9.88 +/- 12.61 to 4.20 +/- 9.24 [hours/day]) and number of patients experiencing AF episodes (from 26 to 13) were observed during CRT. Conclusions: (1) Diagnostic features for long-term monitoring of physiological variables provide useful information on the state and course of AF and may improve disease management. (2) AF burden reduces over time during the first 3 months after CRT implantation.