Abstract 13592: QRS 3D Voltage Time Integral (3D QRS Area) is a Predictor for Pacing Induced Cardiomyopathy

Introduction: The instantaneous absolute 3D ECG voltage integrated over the duration of QRS (VTI QRS-3D ), also measured as 3D QRS area, is a marker for left ventricular electrical dyssynchrony in patients with left bundle branch block. Hypothesis: We sought to investigate if VTI QRS-3D predicts pacing induced cardiomyopathy in patients with chronic (>3 months) right ventricular pacing (RVp). Methods: We retrospectively evaluated RVp ECGs from consecutive patients with pacing induced cardiomyopathy (left ventricular ejection fraction ≤50%) and compared to patients with normal ejection fraction (>50%). Patients were excluded if they did not have ECG and/or echocardiogram. 12-lead ECGs were converted to orthogonal X, Y, Z leads using Kors matrix. VTI QRS-3D was obtained by voltage-time-integral from root-mean-squared 3D ECG. Results: We analyzed 320 RVp patients (age 73 ± 14 years, 40% female), 206 with preserved ejection fraction (LVEF 60.4 ± 4.1%) and 114 with pacing induced cardiomyopathy (LVEF 29.2 ± 8.1%). Pacing induced cardiomyopathy was associated with a longer QRS duration, larger QRS voltage and larger VTI QRS-3D (Table). VTI QRS-3D ≥90 μVs had 81% sensitivity to identify pacing induced cardiomyopathy (specificity 47%). Conclusions: In the setting of chronic right ventricle pacing, QRS 3D voltage time integral ≥90 μVs on ECG can be used as a screening tool to identify patients needing further evaluation for cardiomyopathy.