Distal His bundle pacing normalized the QRS complex and allowed measurement of left bundle branch refractory periods, which were within the normal range in two patients with LBBB.
Case Report (n=2)
Electrophysiological studies were carried out in two patients with an idiopathic left bundle branch block. Consistent distal His bundle pacing resulted in the normalization of the QRS complex in both patients. Extrastimulation during basic distal His pacing at several cycle lengths was carried out successfully. Using this technique, the refractory periods of the left bundle branches were measured and found to be within the normal range. In addition, they decreased with the shortening of the basic cycle length. These results demonstrated the possibility of determining the refractoriness of the left bundle branch by His bundle pacing in patients with left bundle branch block. Hypotheses are postulated about the presumed location of the lesion responsible for the left bundle branch block.
Belhassen et al. (Thu,) conducted a case report in idiopathic left bundle branch block (n=2). Distal His bundle pacing and extrastimulation was evaluated on Refractory periods of the left bundle branches. Distal His bundle pacing normalized the QRS complex and allowed measurement of left bundle branch refractory periods, which were within the normal range in two patients with LBBB.