Left bundle branch pacing vs ventricular septal pacing for cardiac resynchronization therapy

Figures

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  Figure 1. Examples of pacing electrocardiograms and sheath angiographies to delineate the depth of the lead in the septum. Examples of illustrations and fluoroscopy images with left anterior oblique projection showing the lead depth in the left bundle branch pacing (LBBP) group (A), left ventricular septal pacing (LVSP) group (B), and deep septal pacing (DSP) group (C). (D) Examples of electrocardiograms and ventricular electrograms (EGMs) by unipolar tip pacing in LBBP with left ventricular activation time (LVAT) of 75 ms and QRS duration of 125 ms, in LVSP with LVAT of 93 ms and QRS duration of 138 ms, and in DSP with LVAT of 94 ms and QRS duration of 155 ms. QRSd = QRS duration.

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  Figure 2. Pacing characteristics at implantation and follow-up in LBBP, LVSP, and DSP patients. A: Pacing threshold; B: R-wave amplitude; C: impedance. ns = not significant; other abbreviations as in Figure 1.

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  Figure 3. Comparisons of echocardiographic parameters at baseline and follow-up in patients with LBBP, LVSP, and DSP. A: Left ventricular ejection fraction (LVEF); B: LVEF change; C: cardiac resynchronization therapy (CRT) response rate; D: left ventricular end-systolic diameter (LVESD). ns = not significant; other abbreviations as in Figure 1.

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  Figure 4. Kaplan-Meier curves demonstrating a comparison of time to first heart failure (HF) hospitalization among the 3 groups. A hazard ratio >1 represents an increase in HF hospitalization compared with the LBBP group. The hazard ratio for LVSP was 0.95 (95% confidence interval 0.17–5.19, P = .953) and for DSP was 5.10 (95% confidence interval 1.14–22.78, P = .033). Abbreviations are in Table 1.

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  Figure 5. Survival curves and analysis for all-cause mortality. A hazard ratio >1 represents an increase in deaths compared with the LBBP group. The hazard ratio for LVSP is 1.07 (95% confidence interval 0.10–11.85, P = .956) and for DSP is 7.83 (95% confidence interval 1.38–44.32, P = .020). Abbreviations are in Table 1.