Clinical Electrophysiology -> SCA Risk Assessment: -> Other Noninvasive Techniques D-AB11 - Emerging Innovations to Predict Sudden Death (ID 18) Abstract Plus

D-AB11-06 - Amalgamating Electrophysiological Parameters May Better Define The Multi-factorial Pro-arrhythmic Substrate In Hypertrophic Cardiomyopathy That Causes Risk Of Ventricular Fibrillation (ID 744)

Abstract

Background: Slow conduction and abnormal repolarization are pro-arrhythmic but rarely used in risk scores for sudden arrhythmic death such as those for Hypertrophic Cardiomyopathy (HCM).
Objective: To use global, high-density reconstructed epicardial electrograms with CardioINSIGHT™ to determine the arrhythmic substrate of HCM.
Methods: Normal controls and patients with varying risk for HCM were studied. Body surface potentials from a 252 electrode vest were reconstructed onto a CT heart-torso geometry. We tested markers of conduction and repolarization (QRSd, QTc, Total Activation Time, Total Repolarisation Time) at rest. Ventricular conduction stability (V-CoS) was used to test the impact of exercise on electrophysiology by comparing biventricular activation pattern from a matrix of 10 consecutive rest and peak exercise beats.
Results: HCM VF survivors (n = 15) were non-significantly different from HCM patients without VF (n = 16) and controls without HCM (n = 20) in age and gender (p = 0.08, p = 0.3). 6 measures were found to be statistically significant (p<0.05): mean, minimum and range of V-CoS, as well as total activation time, total repolarization time and QTc. QRSd was not significantly different (p = 0.82). In order to test whether these parameters were conferring risk independently, we created an ordinal logistic model; a latent variable was calculated by the total of each coefficient multiplied by the significant measures (risk-score). This latent variable significantly differentiated all three groups (HCM VF vs HCM p = 0.0017, HCM vs Control p = 0.0031).
Conclusion: Electrophysiological parameters could be used to define an abnormal threshold for risk of arrhythmic death.
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