Transvenous endocardial conduction system pacing in patients with a Fontan operation

Figures

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  Figure 1. Case 1 electroanatomic map (EAM) with notable locations tagged. (A) The EAM was referenced to the cardiac computed tomography data. At (B), the mapping catheter recorded sharp prepotentials along the remnant intraventricular septum, which were targeted for implantation. The lead was able to be implanted nearby at (C) with unipolar guidance, where an early ventricular electrogram was recorded, though no clear conduction system potential was present. When the lead was connected in a bipolar configuration, the position shifted slightly to (D), where the paced QRS duration remained narrow.

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  Figure 2. Paced (A) and intrinsic (B) 12-lead electrocardiograms (ECGs) for case 1. The paced QRS duration of 123 ms is 116% of the intrinsic QRS duration, with a z score of +3.5.14 Paced (C) and intrinsic (D) 12-lead ECGs for case 2 (leads half-standard). The paced QRS axis and duration are nearly identical to intrinsic values, with a z score of +2.5.

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  Figure 3. Case 2 electroanatomic map (EAM) with notable locations tagged. (A) The EAM was referenced to the cardiac computed tomography data. At (B), electrograms recorded by the HD Grid catheter anterior to the ventricular septal defect (VSD) demonstrated conduction system potentials. The lead was implanted at (C), just apical to the VSD, and recorded a sharp pre-QRS fascicular potential. LPA = left pulmonary artery; RV = right ventricle.