Pacing of the specialized His Purkinje conduction system: ‘HOW and FOR WHOM’

Figures

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  Figure 1. An example of current of injury. This image records the 12-lead and the unfiltered unipolar electrogram of the tip of the left bundle branch area pacing lead (sweep speed 200 mm/s). Current of injury is evident as an ST-segment elevation due to electrode fixation trauma and focally damaged endocardial cell membranes.

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  Figure 2. An example of fascicular potential. An interval <25 ms between the recorded potential and QRS suggests that recorded potential is a left bundle fascicular potential and not a left bundle trunk potential (generally 25–35 ms).

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  Figure 3. An example transition of QRS morphology from non-selective-left bundle branch abnormality to selective-left bundle branch abnormality during threshold test. This image captures the 12-lead and the unipolar electrogram (filtered and unfiltered electrograms) of the tip of the lead (sweep speed 100 mm/s). Transition from non-selective-left bundle branch abnormality to selective-left bundle branch abnormality is evident as a change in QRS morphology with a prolonged V6–V1 interpeak interval but without a significant increase of left ventricular activation time (<10 ms).

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  Figure 4. An example transition of QRS morphology from non-selective-left bundle branch abnormality to deep left septal myocardial capture during threshold test. Transition from non-selective-left bundle branch abnormality to myocardial capture is evident as a wider QRS with a prolonged left ventricular activation time.