Abstract 9856: Intrinsic Cardiac Nerve Activities and Atrial Arrhythmias in Patients Recovering From Open Heart Surgery

Abstract

Introduction- Intrinsic cardiac nerve activities (ICNA) are invariable triggers of paroxysmal atrial tachyarrhythmias in ambulatory dogs. We sought to record ICNA in human patients to determine if ICNA are associated with atrial arrhythmias. Hypothesis- ICNA are associated with the development of post-operative atrial arrhythmias. Methods- The study protocol was approved by the IRB. Five patients (56±10 years old; 4 male and 1 female) undergoing open heart surgery consented for this study. Two temporary pacing electrodes were placed on the epicardial fat pad at the left superior pulmonary vein-left atrium (LSPV-LA) junction during surgery. ICNA were continuously recorded for up to 3 days after surgery. Nerve activities were considered present if there was a 3-fold increase in the amplitude over baseline noise. Results- We processed 5440 minutes of recordings (1088±1065 minutes per patient). ICNA were recorded in 10.2% of the time. We identified a total 3914 episodes of high amplitude spike discharge activity (HASDA, Figure A) and 51 episodes of low-amplitude burst discharge activity (LABDA, Figure B). A total of 872 episodes of premature atrial contractions (PACs) were noted. Of those, 308 episodes (35.8%) were preceded by ICNA (Figures A and B). In comparison, among 872 control time segments (3 min prior to the PACs), only 28 episodes (3.2%) were preceded by ICNA ( P <0.001). The absence of ICNA had high specificity (96.8%) for predicting subsequent occurrence of PACs. Conclusions- ICNA can be recorded from human patients in the post-operative period. Both HASDA and LABDA are observed. There is a significant association between ICNA and subsequent PACs.