- A dictionary of medical eponyms

Mobitz' block type I and II

Related people

Atrioventricular block of second degree. Mobitz distinguished two types of second degree AV-block. Type I is characterized by a progressive lengthening of the P-R intervals – identical to Wenckebach period/phenomenon. The very rare Mobitz type II is characterized by intermittent failure to conduct a P wave through the atrioventricular node to the ventricle, with constant PR interval.

The form of second degree atrioventricular block now known as Mobitz type II AV block was first discovered by the English physician John Hay (born 1873) in 1905 and by Karel Frederik Wenckebach (1864-1940) in 1906, independently.

See also Wenckebach's bundle and Wenckebach's phenomenon under Karel Frederik Wenckebach, Dutch-born Austrian internist, 1864-1940.


  • K. F. Wenckebach:
    De Analyse van den onregelmatigen Pols. III. Over eenige Vormen van Allorythmie en Bradykardie.
    Nederlandsch Tijdschrift voor Geneeskunde, Amsterdam, 1898, 2: 1132.
    Wenckebach's phenomenon Zur Analyse des unregelmässigen Pulses.
    Zeitschrift für klinische Medizin, 1899, 36: 181-199.
    Wenckebach's phenomenon Beiträge zur Kenntnis der menschlichen Herztätigkeit. Archiv für Anatomie und Physiologie. Physiologische Abteilung, Leipzig, 1906, 297-354.
    Wenckebach's bundle.
  • J. Hay:
    Bradycardia and cardiac arrhythmia produced by depression of certain of the functions of the heart. The Lancet 1906, 1: 139–143.
  • W. Mobitz:
    Über die unvollständige Störung der Erregungsüberleitung zwischen Vorhof und Kammer des menschlichen Herzens.
    Zeitschrift für die Gesamte Experimentelle Medizin, Berlin 1924, 41: 180–237.

What is an eponym?

An eponym is a word derived from the name of a person, whether real or fictional. A medical eponym is thus any word related to medicine, whose name is derived from a person.

What is Whonamedit?

Whonamedit.com is a biographical dictionary of medical eponyms. It is our ambition to present a complete survey of all medical phenomena named for a person, with a biography of that person.


Whonamedit? does not give medical advice.
This survey of medical eponyms and the persons behind them is meant as a general interest site only. No information found here must under any circumstances be used for medical purposes, diagnostically, therapeutically or otherwise. If you, or anybody close to you, is affected, or believe to be affected, by any condition mentioned here: see a doctor.