Abstract MP083: Autonomic Imbalance at the Level of Atrioventricular Node, but Not at the Level of Sinus Node, is Associated With Sudden Cardiac Death: The Atherosclerosis Risk in Community Study
Introduction: Autonomic imbalance, quantified by decreased heart rate variability (HRV), is associated with increased cardiovascular mortality. It is unknown if autonomic influences on sinus and atrioventricular (AV) nodes are equally important for the risk of sudden cardiac death (SCD).
Hypothesis: Autonomic influences on sinus and AV node are equally strongly associated with increased SCD, non-sudden cardiac death (non-SCD), and non-cardiac death.
Methods: Baseline visit 10-second ECGs (n=14,250) of the Atherosclerosis Risk in Communities (ARIC) cohort were analyzed. Normalized variance of P-onset to P-onset intervals (PPVN) and QRS-onset to QRS-onset intervals (QQVN) was calculated to assess autonomic influence on sinus and AV node respectively. Normalized variance of Rpeak - Rpeak intervals was determined as HRV measure. Values were log-transformed to normalize distribution. SCD served as primary outcome. Secondary outcomes were non-SCD and non-cardiac death. Three Cox regression models were constructed for dichotomized at 20th percentile predictor variables.
Results: Over median follow-up of 24.4 years, there were 497 SCDs (incidence 1.66 [95%CI 1.52-1.82], 742 non-SCDs (incidence 2.48 [95%CI 2.31-2.67], and 3,753 non-cardiac deaths (incidence 12.6 [95%CI 12.1-13.0]) per 1,000 person-years. In paired analysis, LogPPVN was significantly larger than LogQQVN (-7.28±1.06 vs. -7.72±1.24; P<0.0001). There was no difference between LogQQVN and Log RRVN (-7.72±1.24 vs -7.72±1.23; P=0.364). After full adjustment, LogRRVN and LogQQVN were significantly associated with non-SCD and SCD. Association with non-SCD was stronger. LogPPVN was independently associated with non-SCD but not SCD. No value was associated with non-cardiac death.
Conclusion: Autonomic imbalance at the AV node, with likely summary effect at the bundle of His, is associated with SCD and non-SCD. Autonomic imbalance at the SA node is associated with non-SCD only. Autonomic input to SA and AV node should be further studied.
Author Disclosures: S.V. Mukundan: None. M.M. Kabir: None. J. Thomas: None. G. Sedaghat: None. J.W. Waks: None. N. Sotoodehnia: None. W.S. Post: None. C. Henrikson: None. T. Biering-Sørensen: None. S.S. Solomon: None. E.Z. Soliman: None. D.S. Siscovick: None. A. Buxton: None. M.E. Josephson: None. L. Tereshchenko: B. Research Grant; Significant; Gilead. G. Consultant/Advisory Board; Significant; Medtronic and Gilead.
- © 2017 by American Heart Association, Inc.