Iatrogenic Right Bundle Branch Block Correction by Left Bundle Branch Area Pacing

Figures

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  Figure 1. Preprocedural Electrocardiogram and Imaging Preprocedural (A) electrocardiogram, (B) transthoracic echocardiography, and (C) cardiac computed tomography.

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  Figure 2. Electrocardiographic Changes During RV Septal Pacing (A) Fluoroscopic image in the RAO 30° view showing the delivery catheter positioned at the right ventricular septum where complete RBBB developed intraoperatively. (B) Electrocardiogram recorded intraoperatively at the time when advancement of the delivery catheter toward the right ventricular septum induced complete RBBB (dashed red line). The QRS duration was prolonged to 162 ms. CRBBB = complete right bundle branch block; PVC = premature ventricular contraction; RAO = right anterior oblique; RBBB = right bundle branch block.

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  Figure 3. Correction of CRBBB by Left Bundle Branch Area Pacing (A) Fluoroscopic image in the LAO 45° view showing the delivery catheter positioned at the right ventricular septum where complete RBBB developed intraoperatively. (B) Electrocardiogram during pacing from the right ventricular septum at the site where complete RBBB had been induced. Pacing from this location corrected the RBBB with narrowing of QRS duration to 135 ms and resolution of the left anterior fascicular block. CRBBB = complete right bundle branch block; LAO = left anterior oblique; RBBB = right bundle branch block; RWPT = R-wave peak time.

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  Figure 4. Transition of QRS Morphology With Lead Advancement (A) Fluoroscopic image in the LAO 45° view showing the pacing lead advanced more than 2 cm deep into the interventricular septum toward the left ventricular endocardium. At this location, successful LBBAP was achieved. (B) Electrocardiogram during successful LBBAP. Unipolar pacing demonstrated a short V6 R-wave peak time (82 ms) and a V6–V1 interpeak interval of 38 ms, with the QRS complex beginning immediately after the pacing spike, consistent with nonselective left bundle branch pacing. LAO = left anterior oblique; LBBAP = left bundle branch area pacing; RWPT = R-wave peak time.

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  Figure 5. Follow-Up Findings After LBBAP (A) Postoperative electrocardiogram showing atrial fibrillation with a ventricular rate of 115 beats/min. The tracing demonstrates complete RBBB with a QRS duration of 161 ms and concomitant LAFB. (B) Electrocardiogram during ventricular pacing at 1.0 V/0.4 ms with a ventricular rate of 120 beats/min. The paced QRS duration was shortened to 125 ms, with resolution of complete RBBB and LAFB. (C) Postoperative transthoracic echocardiography demonstrating the pacing lead tip (arrowhead) located beneath the left ventricular endocardium. LAFB = left anterior fascicular block; RBBB = right bundle branch block.

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  Visual Summary. Right Bundle Branch Block Correction With Unipolar Left Bundle Branch Area Pacing