Better Lesion Creation And Assessment During Catheter Ablation.

Permanent destruction of abnormal cardiac tissue responsible for cardiac arrhythmogenesis whilst avoiding collateral tissue injury forms the cornerstone of catheter ablation therapy. As the acceptance and performance of catheter ablation increases worldwide, limitations in current technology are becoming increasingly apparent in the treatment of complex arrhythmias such as atrial fibrillation. This review will discuss the role of new technologies aimed to improve lesion formation with the ultimate goal of improving arrhythmia-free survival of patients undergoing catheter ablation of atrial arrhythmias.

Design and rationale of the assessment of proper physiologic response with rate adaptive pacing driven by minute ventilation or accelerometer (APPROPRIATE) trial.

Rate-adaptive sensors are designed to restore a physiologic heart rate response to activity, in particular for patients that have chronotropic incompetence (CI). Limited data exist comparing two primary types of sensors; an accelerometer (XL) sensor which detects activity or motion and a minute ventilation (MV) sensor, which detects the product of respiration rate and tidal volume. The APPROPRIATE study will evaluate the MV sensor compared with the XL sensor for superiority in improving functional capacity (peak VO(2)) in pacemaker patients that have CI. This study is a double-blind, randomized, two-arm trial that will enroll approximately 1,000 pacemaker patients. Patients will complete a 6-min walk test at the 2-week visit to screen for potential CI. Those projected to have CI will advance to a 1-month visit. At the 1-month visit, final determination of CI will be done by completing a peak exercise treadmill test while the pacemaker is programmed to DDDR with the device sensors set to passive. Patients failing to meet the study criteria for CI will not continue further in the trial. Patients that demonstrate CI will be randomized to program their rate-adaptive sensors to either MV or XL in a 1:1 ratio. The rate-adaptive sensor will be optimized for each patient using a short walk to determine the appropriate response factor. At a 2-month visit, patients will complete a CPX test with the rate-adaptive sensors in their randomized setting.