Novel approach to diagnosis of His bundle capture using individualized
left ventricular lateral wall activation time as reference
Abstract
Background: During non-selective His bundle (HB) pacing, it is
clinically important to confirm His bundle capture vs. right ventricular
septal (RVS) capture. The present study aimed to validate the hypothesis
that during HB capture left ventricular lateral wall activation time,
approximated by the V6 R-wave peak time (V6RWPT), will not be longer
than the corresponding activation time during native conduction.
Methods: Consecutive patients with permanent HB pacing were recruited;
cases with abnormal His-ventricle interval or left bundle branch block
were excluded. Two corresponding intervals were compared:
stimulus-V6RWPT and native HBpotential-V6RWPT. Difference between these
two intervals (delta V6RWPT), diagnostic of lack of HB capture, was
identified using receiver operating characteristic (ROC) curve analysis.
Results: A total of 723 ECGs (219 with native rhythm, 172 with selective
HB, 215 with non-selective HB, and 117 with RVS capture) were obtained
from 219 patients. The native HB-V6RWPT, non-selective-, and
selective-HB paced V6RWPT were nearly equal, while RVS V6RWPT was 32.0
(±9.5) ms longer. The ROC curve analysis indicated delta V6RWPT
> 12 ms as diagnostic of lack of HB capture (specificity of
99.1% and sensitivity of 100%). A blinded observer correctly diagnosed
96.7% (321/332) of ECGs using this criterion. Conclusions: We validated
a novel criterion for HB capture that is based on the physiological left
ventricular activation time as an individualized reference. HB capture
can be diagnosed when paced V6RWPT does not exceed the value obtained
during native conduction by more than 12 ms, while longer paced V6RWPT
indicates RVS capture.