Author + information
- Chance M. Witt,
- Richard Sanders,
- Charles Ritrivi,
- Steve Berhow,
- Doug Beinborn,
- Gregory J. Seifert,
- Chad Zack,
- Dorothy Ladewig,
- Joanne M. Powers,
- Scott Suddendorf,
- Samuel Asirvatham and
- Paul Friedman
Background: Prompt termination of atrial fibrillation (AF) by implantable devices could improve symptoms and outcomes. However, electrical cardioversion is painful, making it impractical. Cooling of the myocardium may slow conduction and terminate AF without producing pain.
Methods: Cooling was performed on an in vivo canine heart after thoracotomy. First, two needle electrodes were placed in the myocardium with a Peltier cooling element in between. Pacing was delivered from one electrode. Conduction time to the second electrode was measured at baseline and with increasing levels of cooling. Next, atrial fibrillation was repeatedly induced. Cooling was performed at several atrial locations while measuring time to termination (with no termination defined as 60 seconds).
Results: There were 20 attempts at cooling of the myocardium with measurement of conduction time. A decrease in myocardial temperature was strongly correlated with an increase in conduction time (r = 0.78, p < 0.001) (figure). Eleven attempts at termination of AF by cooling on the left atrium (LA) were compared to nine control attempts, which included cooling on the right atrium, contact on the LA with no cooling, and no myocardial contact. The LA group had a significantly shorter time to termination of AF compared to the control group (22.1 vs. 53.1 seconds, p = 0.001).
Conclusions: Myocardial cooling slows electrical conduction with a dose-response relationship. Cooling on the LA repeatedly terminates AF in a canine model.
Poster Hall, Hall C
Saturday, March 18, 2017, 3:45 p.m.-4:30 p.m.
Session Title: Arrhythmias and Clinical EP: Basic 4
Abstract Category: 4. Arrhythmias and Clinical EP: Basic
Presentation Number: 1238-115
- 2017 American College of Cardiology Foundation