Case report: Challenges and implications of conduction system pacing in pediatrics: Case series

Figures

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  Figure 1. Twelve-lead ECG of case 1 taken at 10 mm/mV and 25 mm/s. (A) Sinus arrest and AV junctional rhythm at a rate of 42 beats per minute with a QRS of 140 ms and bifascicular block, with no evidence of atrial activity. (B) 2.3 s pause during sinus arrest. (C) Post-procedure chest x-ray. (D) 12-lead ECG with nonselective left bundle branch stimulation. ECG, electrocardiogram.

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  Figure 2. (A) 12-lead ECG of case 2 taken at 10 mm/mV and 25 mm/s. Complete AV block with normal axes. The mean atrial rate is 70 bpm, and the mean ventricular rate is 40 bpm. (B) 12-lead ECG taken at 10 mm/mV and 25 mm/s. Unipolar dual-chamber pacing with heart rate at 63 bpm, normal P-wave, and QRS axes. After ventricular stimulation, an immediate onset of the QRS with pseudodelta (black arrow) is observed, which was measured at 90 ms at II, III, aVF, and V6. (C) Venography shows an absent connection of the brachiocephalic vein and a direct connection of the left venous system to the coronary sinus. The final position of the leads in (D) anteroposterior view, (E) right oblique 30°, and (F) left oblique 30° are shown. ECG, electrocardiogram; AV, atrioventricular.

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  Figure 3. (A) Initial 12-lead ECG of case 3 taken at 10 mm/mV and 25 mm/s. PM rhythm with single-chamber pacing. AV dissociation (black arrows point to P waves) with a mean atrial rate of 90 bpm, QRS of 160 ms with inferior and right axis, and late transition. (B) QRS notch progression during the first three turns observed in multiple surface ECG leads (arrows point to V1) during advancement of the ventricular electrode through the interventricular septum. (C) QRS notch progression during the last two turns was observed in V2 during the advancement of the ventricular electrode through the interventricular septum. (D) Dual-chamber pacing in the final position of the ventricular electrode with right bundle branch image. (E) Selective stimulation of the left bundle branch of His. Final ECG with normal P-wave and QRS axes, 80 ms final QRS with right bundle branch image, and late transition. (F) Final position of pacemaker, atrial and ventricular endocardial leads. As it can be seen, the epicardial leads were placed in an unusual position, near the AV junction. ECG, electrocardiogram; AV, atrioventricular.