Karel Frederik Wenckebach

Karel Frederik Wenckebach (1864 – 1940)

Karel Frederik Wenckebach (1864 – 1940) was a Dutch physician.

Known to his colleagues as ‘Venky’ he graduated in 1888 and worked at a zoological institute, but switched to physiology due to his colour blindness precluding a career in zoology.

Wenckebach provided the first descriptions of the beneficial effects of the quinine alkaloids on arrhythmias and an important monograph on beriberi in 1934.

Eponymously affiliated with Wenckebach block (Mobitz type I AV block). The pauses between atrial and ventricular contraction which have been called ‘Wenckebach periodicity’ or ‘Mobitz I’ were initially called ‘Luciani Periods’ by Wenckebach himself, referencing the work of Luigi Luciani on frogs in the 1870s

  • Born 24 March 1864, Den Haag
  • 1881-1888 – Studied medicine at the University of Utrecht
  • 1888-1891 – Worked with Theodur Wilhelm Engelmann, and became familiar with techniques of kymographic recording and rhythm disturbances in frog experiments
  • 1891 – Left Utrecht and entered country practice
  • 1896 – Returned to Utrecht – allowing him to continue clinical and laboratory studies
  • 1898 – Reviewed the patient whose pattern of pulse irregularity would allow him to discover that which became known as ‘Wenckebach periodicity
  • 1901 – Chair of Medicine at the University of Groningen
  • 1904 – Published his book ‘Arrythmia of the Heart
  • 1911-1914 – Chair of Medicine at the University of Strasbourg
  • 1914-1929 – Chair of Medicine at the University of Vienna
  • Died 11 November 1940

Medical Eponyms
Mobitz type I (Wenckebach block)
  • Progressive prolongation of the PR interval culminating in a non-conducted P wave
  • PR interval is longest immediately before the dropped beat
  • PR interval is shortest immediately after the dropped beat
ECG Wenckebach Phenomenon

In 1898 Karel Wenckebach consulted a 40-year-old woman with an irregular pulse which he interrogated using a sphygmogram and tuning fork. He noted there were regular pauses every 3 to 4 beats, but the small extra pulse seen during pauses were longer, and subsequent intervals were smaller. The first interval after each pause was longer, and subsequent intervals were shorter.

Wenckebach credited Luigi Luciani (1840 – 1919) as the first to describe this recurrent pattern in his 1873 frog heart experiments and defined this form of group beating as ‘Luciani’schen Perioden‘ (Luciani periods)

Man spricht in diesen Fällen von einer “periodischen Function” des Herzens; die Gruppen werden nach dem Entdecker “Luciani’sche Perioden” genannt.…es sich hier um eine regelmässige Herzthätigkeit handelt, welche von einem constantcn schädlichen Einfluss gestört wird. Dieser Einfluss ist ein negativ dromotroper Einfluss, wie aus einer sorgfältigen Vergleichung dieses Pulses mit der Ventrikelthätigkeit des in Luciani’schen Perioden klopfenden Froschherzens hervorgeht.

Wenckebach 1899; 37: 478

In these cases one speaks of a “periodic function” of the heart; the groups are called “Luciani periods” after the discoverer… it is a regular cardiac activity, which is disturbed by a constant harmful influence. This influence is a negative dromotropic influence, as can be seen from a careful comparison of this pulse with the ventricular activity of the frog heart pounding in Luciani’s periods.

Wenckebach 1899; 37: 478

Wenckebach’s figure demonstrates a constant atrial rate (top line) with diagonal lines (representing AV conduction) progressively lengthening before a beat being missed/dropped. This is followed by the recommencement of the cycle.

With the advent of electrocardiography in the early 20th century, this form of group beating became known as ‘Wenckebach periodicity‘ and later as ‘Mobitz type I atrioventricular block‘.

Wenckebach periodicity Type I AV block
Wenckebach periodicity – Type I AV block. 1898
Other eponyms
  • Wenckebach phenomenon – the eponymous block, demonstrated after the advent of Einthoven’s string galvanometer electrocardiograph
  • Wenckebach sign – paradoxical movements of the chest in chronic mediastinopericarditis
  • Wenckebach bundle – a band of muscle passing from the SVC to the right atrium
  • Wenckebach heart – small heart positioned in the midline of the thorax (mesocardia)
  • Wenckebach Pills – quinine tablets which he showed could halt paroxysm of atrial fibrillation

Key Medical Attributions
  • Published several papers on embryology whilst still a student
  • First reported ventricular extrasystoles with compensatory pauses in humans and demonstrated that atrial extrasystoles were not accompanied by a compensatory pause
  • Discovered his eponymous block prior to the benefit of clinical electrocardiography and the discovery of the sinoatrial and atrioventricular nodes
  • Successfully used quinine to treat paroxysmal atrial fibrillation

I owe my reputation to the fact that I use digitalis in doses the text books say are dangerous and in cases that the text book say are unsuitable

Quoted BMA meeting July 21st 1937

Major Publications



Eponymous term references

BA MA (Oxon) MBChB (Edin) FACEM FFSEM. Emergency physician, Sir Charles Gairdner Hospital.  Passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | Twitter |

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