Relationship between vectorcardiographic QRSarea, myocardial scar quantification, and response to cardiac resynchronization therapy

• Published in: Journal of electrocardiology 2018-05, Vol.51 (3), p.457-463
• Main Authors: Nguyên, Uyên Châu, Claridge, Simon, Vernooy, Kevin, Engels, Elien B., Razavi, Reza, Rinaldi, Christopher A., Chen, Zhong, Prinzen, Frits W.
• Format: Article
• Language: English
• Subjects: Cardiac magnetic resonance imaging; Cardiac resynchronization therapy; Cardiomyopathy; Heart attacks; Morphology; Myocardial scar; NMR; Nuclear magnetic resonance; Standard deviation; Vectorcardiography
• ISSN: 0022-0736; 1532-8430
• DOI: 10.1016/j.jelectrocard.2018.01.009

To investigate the relationship between vectorcardiography (VCG) and myocardial scar on cardiac magnetic resonance (CMR) imaging, and whether combining these metrics may improve cardiac resynchronization therapy (CRT) response prediction. Thirty-three CRT patients were included. QRSarea, Tarea and QRSTarea were derived from the ECG-synthesized VCG. CMR parameters reflecting focal scar core (Scar2SD, Gray2SD) and diffuse fibrosis (pre-T1, extracellular volume [ECV]) were assessed. CRT response was defined as ≥15% reduction in left ventricular end-systolic volume after six months' follow-up. VCG QRSarea, Tarea and QRSTarea inversely correlated with focal scar (R = −0.44–−0.58 for Scar2SD, p ≤ 0.010), but not with diffuse fibrosis. Scar2SD, Gray2SD and QRSarea predicted CRT response with AUCs of 0.692 (p = 0.063), 0.759 (p = 0.012) and 0.737 (p = 0.022) respectively. A combined ROC-derived threshold for Scar2SD and QRSarea resulted in 92% CRT response rate for patients with large QRSarea and small Scar2SD or Gray2SD. QRSarea is inversely associated with focal scar on CMR. Incremental predictive value for CRT response is achieved by a combined CMR-QRSarea analysis. [Display omitted] •The relationship between vectorcardiography (VCG) and scar on cardiac magnetic resonance imaging (CMR) is elucidated.•VCG QRSarea significantly inversely correlates with focal scar, suggesting that myocardial scar leads to a smaller QRSarea.•Combining QRSarea and CMR focal scar improves CRT response prediction beyond that by either VCG or scar parameters alone.