Abstract 12465: Association of Markers of Electrical Heterogeneity With Premature Ventricular Contractions on 12-Lead Electrocardiogram

Abstract

Introduction: It was recently shown that independent electrophysiological substrate, quantified by global electrical heterogeneity (GEH) measures on ECG, is associated with Sudden Cardiac Death (SCD). However, mechanisms of GEH development are incompletely understood. Hypothesis: We hypothesized that the presence of premature ventricular contractions (PVCs) on 12-lead ECG is associated with GEH. Methods: We analyzed 20,288 participants from the Atherosclerosis Risk in Communities (ARIC) and Cardiovascular Health Studies (CHS). Linear regression models were adjusted for demographics, structural heart disease and its risk factors to assess the association between PVCs and GEH. In a subsequent analysis, we included only those participants (n =478) who had both (a): monomorphic (if multiple) or single PVCs and (b): normal median sinus beat . The distance between PVC’s QRS vector and sinus T vector was calculated assuming the heart as a global structure. Prematurity index (PI) was defined as coupling interval (CI) divided by mean sinus-beat RR interval. SAI QRST (sum absolute interval of QRST interval) was measured as the arithmetic sum of areas under the QRST curve. Results: After adjusting for structural heart disease and its risk factors, the presence of PVCs was associated with a QRS-T angle widening by 6.9 (95% CI: 4.41-9.41) degrees (p < 0.0001), and SAI QRST increase by 7.03 mV*ms (95% CI: 2.58-11.48, p = 0.002). On comprehensive adjustment using our linear regression model, among those with PVCs, 1 standard deviation of decrease in the distance between PVC’s QRS-vector and sinus beat’s T-vector was associated with spatial QRS-T angle increase by 3.6 (95% CI: 0.3-7.2) degrees (p =0.048). In the same model increase in PI by 10% was associated with spatial QRS-T angle increase by 3.0 (95%CI 0.7-4.9) degrees (P=0.010). Conclusions: The presence of PVCs is independently associated with an increase in the GEH. Better alignment between PVC’s QRS-vector and sinus beat’s T-vector (presumed cardiac memory) and less premature PVC was independently associated with wider spatial QRS-T angle.