Abstract 18547: Beat-to-Beat Variations in Activation Recovery Interval Derived From the Right Ventricular Electrogram Can Monitor Arrhythmic Risk Under Anesthetic and Awake Conditions in the Chronic Atrioventriclar Block Dog
Introduction: In the chronic atrioventricular block (CAVB) dog model, beat-to-beat variation in repolarization in the left ventricle (LV) quantified as short-term variability of the left monophasic action potential duration (STVLVMAPD) abruptly increases before the first short coupled ectopic beat (EB), specifically in subjects that demonstrate subsequent multiple EBs and repetitive Torsades de Pointes (TdP) arrhythmias. Applicability of STV to monitor arrhythmic risk 24/7 in clinical practice would be feasible through the use of the intracardiac electrogram (EGM) derived from a right ventricle (RV) lead from a pacemaker or implantable cardioverter defibrillator (ICD). Therefore, we performed 1) a retrospective analysis to show that STVRVMAPD is comparable to the STVLVMAPD 2) a prospective analysis to investigate the value of the STV of the activation recovery interval (ARI) derived from the RV EGM (STVRVARI) to monitor arrhythmic risk in anesthetic (2a) and awake (2b) conditions.
Methods: 1) STVLVMAPD and STVRVMAPD were measured in 30 anaesthetized CAVB dogs inducible (≥3TdP) after a challenge with dofetilide. 2a) Under anesthesia 10 inducible CAVB dogs implanted with an ICD with EGM recording capabilities, were challenged with dofetilide to compare STVRVMAP and STVRVARI. 2b) In 8 CAVB dogs oral cisapride (10-20 mg/kg) was administered to provoke arrhythmias in awake conditions.
Results: 1) Both STVLVMAPD and STVRVMAPD significantly increased before occurrence of the first EB (1.29±0.58 to 3.05±1.70ms and 1.11±0.53 to 2.18±1.43ms respectively (p=0.001). Spearmans rho 0.62 (p<0.01). 2a) STVRVARI increased from 2.82±0.33 to 3.77±0.69ms (p=0.001). Spearmans rho between STVRVMAPD and STVRVARI was 0.42 (p<0.05). 2b) Under awake conditions. 4/8 subjects were inducible with cisapride. In the inducible subjects a significant increase in STVRVARI was observed in the first hour after cisapride from 2.65±0.55 to 3.56±0.30ms (p=0.03).
Conclusion: Behavior of STV derived from the RV is comparable to the LV. STVRVARI increases significantly before the occurrence of an arrhythmia in awake and anaesthetized conditions. This can be integrated in devices to 24/7 monitor arrhythmic (in)stability and initiate and or modify antiarrhythmic therapies.
Author Disclosures: S.C. Wijers: None. A. Bossu: None. D.J. Sprenkeler: None. A. Dunnink: None. J.D. Beekman: None. R. Varkevisser: None. A. Aranda Hernández: None. M. Meine: None. M.A. Vos: Research Grant; Modest; GiLead, Medtronic.
- © 2016 by American Heart Association, Inc.