Upgrade of cardiac resynchronization therapy by utilizing additional His-bundle pacing in patients with inotrope-dependent end-stage heart failure: a case series

Figures

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  Figure 1. (Patient 1) Twelve-lead electrocardiograms during intrinsic conduction and each of the pacing configurations. See text for details. (A) Junctional escape rhythm at presentation (atrial fibrillation with complete atrioventricular block). (B) Escape rhythm 12 months after BiVRVA+LV implantation. Although this escape rhythm was assumed to be a junctional rhythm, the definite origin was unclear due to the co-presence of complete atrioventricular block, permanent atrial fibrillation, and advanced impairment of the His–Purkinje system. (C) Pacing rhythm at BiVRVA+LV implantation. (D) Pacing rhythm 12 months after BiVRVA+LV implantation. (E) His-bundle pacing alone. (F) BiVHB+LV pacing. AF, atrial fibrillation; BiV, biventricular; CAVB, complete atrioventricular block; HBP, His-bundle pacing; LV, left ventricular; mo., month; QRSd, QRS duration; RVA, right ventricular apical.

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  Figure 2. (Patient 1) Fluoroscopic imaging showing BiVHB+LV pacing. Def., defibrillator; HBP, His-bundle pacing; LV, left ventricle; RA, right atrium.

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  Figure 3. (Patient 1) Speckle-tracking echocardiography. (A) Semi-automatic delineation of endocardial borders and definition of the region of interest of six segments of the RV on the apical four-chamber image. (B) Region of interest of the LV on the short-axis images at the papillary muscle level. (C) Time to peak strain curve of six right ventricle segments throughout the cardiac cycle. Please note the difference in the distribution of the peak time (dots) during BiVRVA+LV vs. BiVHB+LV pacing. (D) Analysis of the six segments of the LV. BiV, biventricular; HB, His bundle; LV, left ventricle; RV, right ventricle.

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  Figure 4. (Patient 1) Alterations in the QRSd, standard deviation of the time to peak strain of six segments of the right ventricle, and standard deviation of the time to peak strain of six segments of the left ventricle during intrinsic conduction, BiVRVA+LV pacing, His-bundle pacing alone, and BiVHB+LV pacing. BiV, biventricular; HB, His-bundle; LV, left ventricular; LV-SD, standard deviation of the time to peak strain of six segments of the left ventricle; QRSd, QRS duration; RV, right ventricular; RV-SD, standard deviation of the time to peak strain of six segments of the right ventricle.

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  Figure 5. (Patient 2) Electroanatomical map (CARTO) of the left ventricle during the ablation procedure. The low-voltage area (depicted in red) is defined as sites having local bipolar voltage of <0.6 mV. Red tags indicate ablation sites, and green tags indicate sites where delayed potentials were observed during mapping. Intracardiac electrograms recorded at the septal scar (fractionated delayed potentials) are shown. All abnormal electrograms within the low-voltage area were ablated. ABL, ablation; d, distal; p, proximal.

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  Figure 6. (Patient 2) (A) Twelve-lead electrocardiograms during ventricular activation through the intrinsic conduction before and after ablation. Left panel: Atrial fibrillation with QRS morphologies of right bundle branch block and left anterior hemiblock. Right panel: Possible junctional beats with QRS morphologies of right bundle branch block and left posterior hemiblock pattern. Although this escape rhythm was assumed to be a junctional rhythm, the definite origin was unclear due to the co-presence of complete atrioventricular block and advanced impairment of the His–Purkinje system. (B) Twelve-lead electrocardiograms during pacing. Left panel: BiVRVA+LV pacing before ablation. Mid-panel: His-bundle pacing alone. Right panel: BiVHB+LV pacing. ABL, ablation; BiV, biventricular; HB, His bundle; LV, left ventricular; QRSd, QRS duration; RVA, right ventricular apical.

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  Figure 7. (Patient 2) Fluoroscopic imaging showing BiVHB+LV pacing (A) and intracardiac electrograms recorded at the implantation site (B). The red arrow indicates a possible right bundle branch potential although the co-presence of complete atrioventricular block and the injured His–Purkinje system made its recording and identification difficult. Def., defibrillator; HB, His bundle; LV, left ventricle; PA, posteroanterior; RA, right atrium.

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  Figure 8. (Patient 2) Alterations in the QRS duration, standard deviation of the time to peak strain of six segments of the right ventricle, and standard deviation of the time to peak strain of six segments of the left ventricle during intrinsic conduction, BiVRVA+LV pacing, His-bundle pacing alone, and BiVHB+LV pacing. ABL, ablation; BiV, biventricular; HB, His bundle; LV-SD, standard deviation of the time to peak strain of six segments of the left ventricle; QRSd, QRS duration; RV-SD, standard deviation of the time to peak strain of six segments of the right ventricle.

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