Permanent His Bundle Pacing: A programming and troubleshooting guide

Figures

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  Fig. 1. Nonselective His bundle pacing (NS-HBP) is capture of ventricular myocardium and capture of the HB. NS-HBP is identified by presence of a pseudo delta wave, or “slur,” leading into a narrow QRS complex.

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  Fig. 2. Selective His bundle pacing (S-HBP) is capture of the HB only. S-HBP is identified by an isoelectric, or “flat straight line,” preceding the QRS complex.

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  Fig. 3. Identifying BBB recruitment. A transition from NS-HBP to S-HBP is noted on the programmer strip. However, the programmer strip does not show BBB recruitment and loss of BBB recruitment. A 12-lead rhythm strip is necessary to identify the loss of BBB recruitment. In this example BBB recruitment is lost when the output is decremented down and the morphology transitions to S-HBP.

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  Fig. 4A. Bipolar vs unipolar sensing. Starting at the “last session” the R waves doubled on a stable chronic lead in the HB location. The R waves doubled due to a change from bipolar sensing to unipolar sensing.

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  Fig. 4B. Although the R waves are often larger in the unipolar sensing configuration, programming unipolar sensing is not advised due to myopotentials and/or noise that can be assessed. Here we have a VT-NS episode that demonstrates constant noise on the unipolar EGM and the noise is not seen on the bipolar EGM.

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  Fig. 5. Demonstration of inappropriately programmed AV delays on POD #1. By simply changing the mode from DDD to VVI, pseudofusion is avoided and the paced beats result in a more narrow QRS complex and partial recruitment of the BBB.

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  Fig. 6. HBP morphology transitions while decrementing the pacing output on a 12-lead rhythm strip and the device electrograms (EGMs). The first highlighted area on the 12-lead rhythm strip is NS-HBP; evident by the pseudo delta wave, or “slur,” leading into a narrow QRS complex. The second highlighted area on the 12-lead rhythm strip is S-HBP; evident by the isoelectric, or “flat straight line,” preceding the QRS complex. On the device electrogram, NS-HBP is noted in the first highlighted area— a negative evoked response, a short stim-peak, and a wider far-field QRSd. The morphology transitions to S-HBP— a positive evoked response, the stim-peak is longer, and the far-field QRSd is narrower.

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  Fig. 7. There is no change in morphology on the device EGMs. However, the 12-lead rhythm strip demonstrates a transition from NS-HBP to loss of HB capture, evident by the widening of the QRS. In order to identify the transition from NS-HBP to RV septal capture, a 12-lead rhythm strip is essential.

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  Fig. 8A. Importance of 12-lead rhythm strips during follow-up. The device EGM appears to be appropriately capturing the HB during a VVI threshold test.

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  Fig. 8B. However, the 12-lead rhythm strip during the same threshold test displays capture of the atrium with the His lead, resulting in 2:1 AV conduction.