Infranodal block: diagnosis, clinical significance, and management

[Historical development of diagnosis of bradyarrhythmias : The early years of clinical electrophysiology in Germany]

The introduction of His bundle electrography by Benjamin Scherlag (New York) in 1969, together with programmed stimulation of the heart by Philip Coumel (Paris) in 1967, and Hein Wellens (Amsterdam) in 1972, were decisive turning points on the way to invasive electrophysiology and the development of an independent, now distinctly interventional subspecialty of cardiology. The main topic of the 1970s was bradycardic arrhythmias, promoted by pacemaker therapy, which had been introduced just over 10 years earlier. The recording of the potentials of the bundle of His and other recording locations in the atria and ventricles allowed a differentiated assessment of the excitation process and the refractory periods. High-rate atrial stimulation to determine sinus node recovery time and premature stimulation to determine sinoatrial conduction time were developed to analyze sinoatrial node function. This article describes the introduction of His bundle electrography in a gradually increasing number of centers in Germany and their scientific contribution.

Congenital polycystic tumor of the atrioventricular node: possible familial occurrence and critical review of reported cases with special emphasis on histogenesis

Congenital polycystic tumor of the atrioventricular node is a rare tumor of disputed histogenesis. It constant location in the atrioventricular node separates it from other cardiac cysts and tumors of indisputable endodermal origin. New studies of the embryogenesis of conduction tissues provide a reasonable explanation for the site of the lesion. Morphologic and histochemical features of the tumor fail to conclusively favor either a mesothelial or an endodermal genesis. A recently studied case provides some new morphologic observations (complex desmosomes, granule-containing epithelial cells) and suggests the possibility of of familial occurrence.