Introduction Narrowing of the QRS and overcoming left bundle branch block (LBBB) with His bundle pacing (HBP) has been previously described. We present the first 2 reported cases of left bundle branch (LBB) delay with evidence of a split His electrogram during unipolar mapping from the tip of the His bundle (HB) lead during pacemaker implantation. These findings suggest that the site of LBB del...

Automatic junctional tachycardias are rare supraventricular tachyarrhythmias observed mainly in infants and children. This arrhythmia has a high mortality rate. We report the case of a 22-month-old infant in which the electrophysiological study disclosed an incessant junctional tachycardia originating from an automatic focus located in the His bundle region. Radiofrequency pulse delivery to the...

BACKGROUND The ATP7A gene encodes the ATP7A protein, which is a trans-Golgi network copper transporter expressed in the brain and other organs. Mutations in this gene cause disorders of copper metabolism, such as Menkes disease. Here we describe the novel and unusual mutation (p.T1048I) in the ATP7A gene of a child with Menkes disease. The mutation affects a conserved DKTGT1048 phosphorylation ...

Multiple points of instruction discussed practically in the context of a challenging case make for a memorable learning experience. In this installment of Teaching Rounds in Cardiac Electrophysiology, Nayyar et al elucidate the unique findings and analysis in such a manner and take us through to diagnosis and a treatment plan that eliminated arrhythmia without having to ablate all of the abnorm...

SUMMARY Traditionally the site of impulse formation in so-called A-V nodal rhythms has been considered to be within the upper, middle, and lower portions of the A-V node. In this study, evidence obtained supports the concept that the His bundle and not the A-V node is the pacemaker site in nodal rhythms. His bundle activity was recorded in clinical cases of nodal rhythms and A-V dissociation by...

SUMMARY Because a great majority of patients with chronic complete heart block have bilateral bundle-branch lesions, it becomes important to recognize earlier degrees of bilateral bundle-branch block. The H-V interval in the His bundle electrogram during unilateral bundle-branch block reflects the conduction primarily through the contralateral bundle branch, and thus the His bundle electrogram ...