Figure legends
Figure 1. Precordial electrocardiogram leads.
A: Sinus rhythm with atrioventricular block and narrow QRS. B: Same patient as A with non-selective HBP. C: Sinus rhythm with narrow QRS. D: Same patient as C with LBBAP. E: Sinus rhythm with LBBB. F: Same patient as E with resynchronization by HBP. G: Sinus rhythm with LBBB. H: Same patient as G with resynchronization by LBBAP.
Figure 2. Post-procedure imaging tests.
Chest X-ray. A: HBP; B: LBBAP. Transthoracic echocardiogram, long-axis 4-chamber view. C: lead placed in His bundle (white arrow); D: LBBAP lead penetrating interventricular septum (asterisk).
Figure 3: Progress of pacing parameters.
A: Pacing threshold in volts; B: Sensed R-wave amplitude in millivolts. At implantation (blue box) and at three months (red box).
Figure 4: QRS width analysis in patients with baseline QRS < 120 ms.
Baseline QRS (blue box), paced QRS (green box) and QCI (orange box). NS-HBP: non-selective His bundle pacing; S-HBP: selective His bundle pacing.
Figure 5: QRS width analysis in patients with baseline QRS ≥ 130 ms.
Baseline QRS (blue box), paced QRS (green box) and QCI (orange box).