Figure legends
Figure 1 . Electroanatomical map of patient #4 with congenitally corrected transposition of great vessels and dextrocardia performed with a multipolar catheter (HD Grid, Abbott). Green tags correspond to His bundle recording with adequate pacing thresholds. The lower panel shows the His bundle electrograms recorded with the HD Grid catheter. SVC: superior vena cava; IVC: inferior vena cava; CS: coronary sinus; SPV: subpulmonic ventricle.
Figure 2 . Figure 2. Baseline (left) and final paced 12 lead ECG (right) in the 5 patients with left ventricular septal pacing (LVSP). Sweep speed 25 mm/s.
Figure 3 . Patient #7 (D-TGA status post Senning atrial switch operation). Panel A and B show the right (RAO) and left anterior oblique (LAO) fluoroscopic views of the final lead position. The left bundle branch pacing (LBBP) lead is indicated with an asterisk. The other endocardial ventricular lead was implanted as a back-up pacing lead. Panel C shows the electrogram recorded from the pacing lead tip corresponding to a large anterior fascicle potential and a non-selective LBBP beat. Panels D and E show the baseline epicardial paced ECG and the final LBBP 12-lead ECG, respectively.
Figure 4 . A) mean systemic left ventricular (LV) ejection fraction at baseline and at last follow-up measured by biplane Simpson’s method in patients with a systemic LV. B) mean systemic right ventricle (RV) fractional area change in patients with a systemic RV. C) evolution of NYHA class from baseline to last follow-up.
Figure 5 . Patient #9 (D-TGA status post Senning atrial switch operation). Panels A and B show the electroanatomical maps of the PVA (purple) and SVA (cyan) performed with the CARTO system with yellow tags representing His bundle electrograms recorded in the PVA. Panels C and D show the AP and LAO views of the patient with the 3830 lead implanted in the left anterior fascicle area in the subpulmonic ventricle (red asterisc). Yellow tags represent His-bundle area extrapolated from the electroanatomic maps. Panel D shows a spontaneous beat with the anterior fascicle potential (red arrow) registered at the tip of the 3830 lead followed by a paced beat showing selective capture of the left bundle. PVA: pulmonary venous atrium; SVA: systemic venous atrium; Ap: anteroposterior view; LAO: left anterior oblique view; SVC: superior vena cava; IVC: inferior vena cava.
Figure 6 . Patient #4 with congenitally corrected transposition of great vessels and dextrocardia. Panels A and B showing left (LAO) and right anterior oblique (RAO) fluoroscopic views of the implanted leads. Note that a radioopaque line (red asterisk) can be seen at the tip of the ventricular lead in panel B corresponding to the VSD calcified patch that served as an anatomical reference for lead implantation. Panel C shows the His electrogram (red arrow) recorded from the lead tip (unipolar) and non-selective His bundle-pacing. Panels D and E show the native QRS and final paced QRS with non-selective HBP.
Figure 1.