Woldemar Mobitz
Woldemar Mobitz (1889-1951) was a German physician.
Mobitz is eponymously linked with the classification of second-degree atrioventricular (AV) block. Born in St. Petersburg, Russia, he relocated to Germany in early childhood following the death of his father. Educated in Meiningen, Freiburg, and Munich, Mobitz completed his medical studies in 1914, initially training in surgery before shifting to internal medicine. By the early 1920s, he had established himself as a lecturer at the University of Munich, focusing on cardiac arrhythmias and AV conduction.
Between 1922 and 1924, Mobitz published a series of insightful papers on extrasystoles and AV dissociation, culminating in his 1924 landmark study that distinguished two types of second-degree AV block. Mobitz type I (Wenckebach) was characterized by progressive PR prolongation and was largely functional and reversible, while Mobitz type II (Hay) was associated with fixed PR intervals and structural disease of the conduction system. This clear pathophysiological distinction became a cornerstone of electrocardiographic diagnostics and remains integral to cardiology today.
Mobitz contributed original research across diverse internal medicine domains including congenital and acute porphyria, primary pulmonary arteriosclerosis, autonomic control of circulation, cardiac action potentials, gas exchange during exertion, and the early clinical use of isotopes.
Despite his scientific contributions, Mobitz never attained a full professorial chair, possibly due to chronic illness or his introverted personality. He spent much of his academic career at the University of Freiburg, interrupted by a wartime appointment in Magdeburg. Following the war, he returned to Freiburg, where he continued his work until his death in 1951. Though he received little formal recognition in his lifetime, Mobitz’s name endures through his enduring contributions to the understanding of AV conduction block.
Biography
- 1889 – Born May 31 in St Petersburg, Russia, son of a prominent surgeon.
- 1895 – Moved with family to Tübingen, Germany, before his sixth birthday.
- 1908–1914 – Studied medicine at the University of Freiburg then transferred to University of Munich. Graduated MD with thesis Beiträge zur Klinik der Basedow’schen Krankheit
- 1914–1918 Worked in surgical clinics in Berlin and Halle, then interned at the First Medical Clinic in Munich.
- 1921 – Lecturer at the First Medical Clinic, University of Munich, under Professor Ernst von Romberg (1865-1933); research focused on cardiovascular disease and arrhythmias.
- 1922 – Presented at the Medical Convention for Internal Medicine in Vienna about the nature of time intervals between atrial and ventricular action
- 1923 – Presented on AV conduction disturbances in humans at the meeting of the Association of Munich Specialists of Internal Medicine – the first occasion on which he first classified second-degree AV block into type I and II
- 1924 – Published landmark classification of second-degree AV block: “Über die unvollständige Störung der Erregungs-überleitung zwischen Vorhof und Kammer des menschlichen Herzens” introducing Mobitz type I and II blocks.
- 1925 – Professor and Chief Resident at the Internal Medical Clinic in Freiburg.
- 1928 – Associate Professor and Chief of Staff, Clinic of Internal Medicine, University of Freiburg, by invitation of Hans Eppinger Jr.
- 1934 – Briefly headed the clinic following dismissal of Siegfried Thannhauser, but replaced within 10 days by Otto Bickenbach, a Nazi party member.
- 1943 – Appointed Director, State Medical Clinic, Magdeburg-Sudenburg.
- 1946 – Returned to University of Freiburg, resumed academic activities.
- 1949 – Published work on differential diagnosis of lung infiltrates and on medical uses of isotopes.
- 1951 – Died April 11 in Freiburg, aged 61, after a long illness with laryngeal tuberculosis.
Medical Eponyms
Second-degree Atrioventricular block
Mobitz applied a mathematical and graphical approach to cardiac arrhythmias, analyzing the relationship between atrial rate, premature beats, and AV conduction dynamics.
In 1924, published a landmark classification of second-degree atrioventricular (AV) block into two physiologically distinct types—based on ECG patterns and pathophysiological correlation.
- Type I AV block [Mobitz type I (Wenckebach)] as functional and typically reversible, with no significant AV nodal or His bundle pathology on autopsy.
- Ttype II AV block [Mobitz type II (Hay)] as more serious, often progressing to complete heart block, and associated with syncope (Stokes-Adams attacks) and sudden death; believed it reflected structural injury to the His bundle.
The top line of the laddergram demonstrates the time between atrial contraction (equivalent to P-P intervals) to be constant.
The middle diagonal line depicts AV conduction (P-R interval), which gradually lengthens until the point at which AV conduction is absent altogether. After this point, the cycle starts again.
The bottom line of the laddergram illustrates increasing time periods between ventricular contraction (R-R interval), before a long pause as a result of the dropped beat, followed by a repeat of the cycle.
Effectively a 6:5 Type I block.
rial rate is constant, AV conduction rates are constant when successful, and ventricular contraction is present only after successful AV conduction.
The rate of ventricular contraction is the same as rate of atrial contraction, or where AV block occurs, is an exact multiple of the atrial rate, as below algebraically
Type II AV Block: Laddergram – Mobitz 1924.
It may appear astonishing to the clinician that the results presented here are seemingly based purely on mathematical considerations. However, the idea that all theoretical concepts of rhythm disturbances developed so far are derived from measuring the recorded tracings, and correlating numerical data will give the same approval for this method of reasoning in regard to the field of clinical medicine as it has already been given for the methods of pure chemistry and physics in regard to other fields
Controversies
Misattributed Portrait
The most commonly used portrait of Woldemar Mobitz is incorrect. It depicts John Milton Hay (1838–1905), the American statesman and former U.S. Secretary of State. This error probably arose from a confusion between John Milton Hay and John Hay (1873–1959), the English cardiologist whose work Mobitz classified as type II AV block. This confusion has led to the image of the diplomat being misattributed in journal articles (e.g. Clin Cardiol 2009) and widely online, where it is now mistakenly accepted as Mobitz.
Major Publications
- Mobitz W. Beiträge zur Klinik der Basedow’schen Krankheit. Thesis dissertation 1914
- Mobitz W. Über die unvollständige Störung der Erregungs-überleitung zwischen Vorhof und Kammer des menschlichen Herzens. [On the partial block of impulse conduction between atrium and ventricle of human hearts] Zeitschrift Fur Die Gesamte Experimentelle Medizin. 1924;41:180-237 [Mobitz Blocks]
- Mobitz W. Fortsetzung der Aussprache über seltenere Electrokardiogramme und Demonstrationen von solchen. Münchener medizinische Wochenschrift. 1922; 69: 333
- Mobitz W. Zur Frage der atrioventrikulären Automatie. Münchener medizinische Wochenschrift. 1922; 69: 762
- Mobitz W. Über die verschiedene Entstehungsweise extrasystolischer Arhythmien beim Menschen, ein Beitrag zur Frage der Interferenz mehrerer Rhythmen. Zeitschrift Fur Die Gesamte Experimentelle Medizin. 1923; 34: 490-507
- Mobitz W. Die Ueberleitungsstörung am menschlichen Herzen [The disturbances of AV conduction in human hearts]. Münchener medizinische wochenschrift 1923; 70: 1376
- Mobitz W. Zur Frage der atrioventrikulären Automatie: Die Interferenzdissoziation [To the question of atrioventricular automation: the interference dissociation]. Deutsches Archiv für klinische Medizin. 1923; 141: 257–289.
- Mobitz W. Über die vollständige Störung der Erregungsüberleitung zwischen Vorhof und Kammer des Herzens. Thesis 1924
- Mobitz W. Über die unvollständige Störung der Erregungsüberleitung zwischen Vorhof und Kammer des menschlichen Herzens. Zeitschrift für die Gesamte Experimentelle Medizin, Berlin, 1924; 41: 180-237
- Mobitz W. Die Ermittlung des Herzschlagvolumens des Menschen durch Einatmung von Äthyljodid. Klinische Wochenschrift 1926; 5: 985–986
- Mobitz W. Über den partiellen Herzblock. Zeitschrift für klinische Medizin 1928; 107: 449–462
- Henderson Y. Mobitz W. The constant rate of absorption of ethyl iodide vapor and its significance as a basis for measuring the circulation. The American Journal of Physiology 1930: 92(4): 707-715
- Mobitz W. Neueres über Isotope und ihre Verwendung in der Medizin [News about isotopes and their use in medicine]. Pro Medico 1949;18:37–39
References
Biography
- Heilmeyer L. Woldemar Mobitz. Deutsche medizinische Wochenschrift, 1951; 76(34): 1030-1031
- Münchener medizinische Wochenschrift 1951; 93(2): 1539, 1579
- Wormer EJ. Syndrome der Kardiologie und ihre Schöpfer. 1989: 169–174
- Lüderitz B, Barold SS. Woldemar Mobitz. J Interv Card Electrophysiol. 2002 Dec;7(3):261.
- Upshaw CB Jr, Silverman ME. Woldemar Mobitz: early twentieth century expert on atrioventricular block. Clin Cardiol. 2009 Nov;32(11):E75-7.
Eponymous terms
- Barold SS, Hayes DL. Second-degree atrioventricular block: a reappraisal. Mayo Clin Proc. 2001 Jan;76(1):44-57.
- Silverman ME, Upshaw CB Jr, Lange HW. Woldemar Mobitz and His 1924 classification of second-degree atrioventricular block. Circulation. 2004 Aug 31;110(9):1162-7.
- Barold SS, Israel CW, Herweg B. Challenges in the terminology of second-degree atrioventricular block. Herzschrittmacherther Elektrophysiol. 2024 Dec;35(4):324-326.
- Barold SS, Herweg B. Centennial of the original description of Mobitz type II second-degree atrioventricular block. J Cardiovasc Electrophysiol. 2024 Apr;35(4):846-847.
- Cadogan M. Eponymythology: Second-degree Atrioventricular block. LITFL
- Cadogan M. History of the Electrocardiogram. LITFL
- Cadogan M. History of Second-degree Atrioventricular block. LITFL
Eponym
the person behind the name
