His bundle recordings established the diagnosis of bilateral bundle-branch block with WPW syndrome, demonstrating the preexcitation pathway conducted and blocked with normal pathways.
Case Report (n=1)
An example of bilateral bundle-branch block (RBBB) in the presence of WPW syndrome in which diagnosis was established with the aid of His bundle recordings is presented. Complete RBBB and intermittent block of the superior and inferior divisions of the left bundle branch were coexistent for at least 2 years before complete heart block (trifascicular block) occurred. It was demonstrated that the preexcitation pathway conducted and blocked together with the normal pathways. It is suggested that the anomalous bundle in this case traveled with the normal pathways and that this close relationship is more common than has been suspected. Retrograde V-A conduction at 1:1 ratio was present during electrical stimulation of the right ventricle and the anomalous bundle was used for retrograde spread of activation from the ventricles to the atria. The retrograde P waves, thus produced, conducted antegrade through the His bundle (reciprocation) but reached the ventricles only when they appeared near the end of the T waves of the preceding beats. The mechanism of supramaximal conductivity or excitability, therefore, appears to be a plausible explanation.
Rashid A. Massumi (Sat,) conducted a case report in Bilateral bundle-branch block combined with Wolff-Parkinson-White syndrome (n=1). His bundle recordings was evaluated. His bundle recordings established the diagnosis of bilateral bundle-branch block with WPW syndrome, demonstrating the preexcitation pathway conducted and blocked with normal pathways.