89-06: Assessment of vectorcardiographic parameters of the paced QRS complex as prediction of acute hemodynamic response in CRT patients

Abstract

Purpose of the study: Vectorcardiography (VCG) has been recently reported as a promising tool to predict acute hemodynamic response in CRT patients. We evaluated the ability of 9 VCG parameters in addition to QRS duration of the biventricular (BV) paced QRS complex to predict acute hemodynamic CRT response. Methods: VCG parameters from 753 BV paced electrocardiograms (25 patients, in each patient 5 BV, 1 multispot, 1 multivein setting and each setting at 5 different atrioventricular delays) were calculated according to Frank orthogonal lead system using custom made software. Maximum vector amplitude (VA) and maximum QRS area (AREA) in the frontal (X), horizontal (Y) and left sagittal plane (Z) and in 3D projection (3D) were measured. Additionally global QRS duration (QRSD) and time from maximum peak amplitude to the end of the QRS complex were assessed (TMax). For every VCG parameter the difference (Δ) between the BV paced and atrial paced QRS-complex was calculated. VCG-parameters were compared to changes in left ventricular pressure, expressed as dP/dt max. An increase of 10% in dP/dt max was considered as acute hemodynamic response (AHR). Results: All patients had an indication for CRT according to current ESC/AHA guidelines (84% male, 100% LBBB, mean QRSD 180 ± 25ms, 40%/60% NYHA II/III). Hemodynamic response was observed in 655 (84%) of the BV paced electrocardiograms. From all vectorcardiographic parameters VA3D, ΔVA3D, AREAZ, ΔAREAZ, ΔAREA3D, TMax and ΔQRSD differentiated AHR response from non-response (Table 1). The diagnostic accuracy to predict response was the highest for ΔAREAZ (AUC = 0.799), and ΔAREA3D (AUC = 0.723) (Table 1). Conclusion: Reduction in QRS area, measured in the left sagittal plane or in 3D projection, during BV pacing seems a useful VCG parameter to predict acute hemodynamic response in CRT patients. This method may be an easy, non-invasive tool for CRT optimization.