AV Junctional Ablation Allowing More Effective Delivery of Cardiac Resynchronization Therapy in Patients with Intra‐ and Interatrial Conduction Delay

Abstract

We report two patients with cardiac resynchronization therapy (CRT) devices and evidence of refractory heart failure in whom impaired intraatrial conduction in one patient, and interatrial conduction in the other, prohibited optimization of the atrioventricular (AV) timing sequence. The patient with intraatrial conduction delay exhibited late right atrial sensing and latency during right atrial pacing that required programming of a short-sensed AV delay and long-paced AV delay (wide differential AV delay). In both patients AV junctional ablation and echocardiography-guided device optimization significantly improved heart failure.

Impact of baseline PR interval on cardiac resynchronization therapy outcomes in patients with narrow QRS complexes: an analysis of the ReThinQ Trial

“…Similar observations were also made in a subanalysis of the MIRACLE and MIRACLE-ICD studies, where patients with baseline PR interval >200 ms showed significantly greater improvements in 6-month VO 2 max (12.7 to 14.1 mL/kg min) and in 6-min walk distance (251 to 327 m) compared to patients with a baseline PR≤200 ms (VO 2 max 14.9 to 15.0 mL/kg min and walk distance 307 to 337 m) [16]. Finally, a small case series demonstrated that two patients with short baseline PR intervals were able to achieve a significant improvement in HF only after undergoing AV junction ablation following CRT implantation, demonstrating the important role of native AV conduction hindering effective CRT [17]. These data underscore the importance of appropriate AV timing in achieving maximal benefit from CRT; differently stated, a short PR interval at baseline may negate some of the benefits of CRT and may contribute to non-response.…”

Atrial fibrillation complicating congestive heart failure: Electrophysiological aspects and its deleterious effect on cardiac resynchronization therapy

“…A Patients in AF do not have AV synchrony, thus it is not possible to perform a synchronized pacing with adequately programmed AV intervals . [88][89][90][91] Therefore, the efficacy of CRT is compromised since adequate capture of biventricular pacing can not be guaranteed. In addition, since AF patients usually have a consistent or intermittent rapid ventricular rate, they require higher pacing rates.…”