POSTER - #KU0032

 Right-to-Left Ventricular Pacing Offset In Cardiac Resynchronization Therapy -

Comparison of Electrocardiographic Imaging (ECGI) with QRS Duration & QRS Area

Amit Noheria, MBBS, SM, Christopher M. Andrews, PhD, Phillip S. Cuculich, MD, John Gorcsan III, MD, Douglas L. Mann, MD, Yoram Rudy, PhD
The University of Kansas, Kansas City, Kansas, Washington University, St. Louis, Missouri

INTRODUCTION
• Biventricular pacing for cardiac resynchronization therapy (CRT) to alleviate heart failure can be delivered with different RV-LV pacing offsets. ¹
• There is heterogeneity in cardiomyopathy, scar distribution, lead locations and pacing latencies.
• Individually optimizing RV-LV offset may improve electrical resynchrony and clinical response to CRT.

OBJECTIVES
• To study impact of RV-LV pacing offsets on global ventricular activation with electrocardiographic imaging (ECGI).²
• To evaluate regular ECG as a surrogate for ECGI to identify optimal RV-LV pacing offset.

METHODS
• We studied RV-LV offsets in 20 ms decrements from +40 to -80 ms with ECGI & 12-lead ECG in 5 CRT recipients.
• We obtained ventricular electrical uncoupling (VEU) as the difference in mean activation times over RV and LV epicardium with ECGI.³
• We got paced QRS duration (QRSd) from ECG.
• We reconstructed vectorcardiogram in orthogonal x, y, z coordinates from ECG using Kors conversion matrix and obtained 3D QRS_AREA (root-mean-square of QRS area in x, y, z axes).^4,5
• In individual patients, we obtained correlation coefficients (r) of VEU and total activation time with QRSd and 3D QRS_AREA, and compared them using Mann-Whitney U test.

RESULTS
• Progressive RV-LV offset resulted in progressive changes in VEU in all patients. (Figure 1)
• RV-LV offset with least absolute VEU was different in different pts. (See solid red curves in right panel)
(View poster)

Absolute VEU correlated with 3D QRS_AREA [mean r 0.65 (range 0.29, 0.86)] but not QRSd [mean r 0.12 (range -0.33, 0.61)], p=0.03.

Epicardial total activation time correlated with QRSd [mean r 0.95 (range 0.93, 0.98)] but not 3D QRS_AREA [mean r -0.11 (range -0.48, 0.45)], p=0.008.
(View poster)

CONCLUSIONS
• It is feasible to use ECGI for selecting RV-LV pacing offset to minimize ventricular electrical uncoupling (VEU) for maximizing electrical resynchrony.
• Paced 3D QRS_AREA (rather than paced QRSd) from ECG correlates with VEU and can be used as a surrogate for ECGI.

REFERENCES
1. Noheria A, Sodhi S, Orme GJ. The Evolving Role of Electrocardiography in Cardiac Resynchronization Therapy. Curr Treat Options Cardiovasc Med. 2019;21(12):91.
2. Ghosh S, Silva JNA, Canham RM, et al. Electrophysiologic substrate and intraventricular left ventricular dyssynchrony in nonischemic heart failure patients undergoing cardiac resynchronization therapy. Heart Rhythm. 2011;8(5):692-699.
3. Ploux S, Lumens J, Whinnett Z, et al. Noninvasive electrocardiographic mapping to improve patient selection for cardiac resynchronization therapy: beyond QRS duration and left bundle branch block morphology. J Am Coll Cardiol. 2013;61(24):2435-2443.
4. Kors JA, van Herpen G, Sittig AC, van Bemmel JH. Reconstruction of the Frank vectorcardiogram from standard electrocardiographic leads: diagnostic comparison of different methods. Eur Heart J. 1990;11(12):1083-1092.
5. van Stipdonk AMW, Horst ter I, Kloosterman M, et al. QRS Area Is a Strong Determinant of Outcome in Cardiac Resynchronization Therapy. Circ Arrhythm Electrophysiol. 2018;11(12):e006497.