Medical Terminology Daily - Est. 2012

Medical Terminology Daily (MTD) is a blog sponsored by Clinical Anatomy Associates, Inc. as a service to the medical community. We post anatomical, medical or surgical terms, their meaning and usage, as well as biographical notes on anatomists, surgeons, and researchers through the ages. Be warned that some of the images used depict human anatomical specimens.

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A Moment in History

Jean George Bachman

Jean George Bachmann
(1877 – 1959)

French physician–physiologist whose experimental work in the early twentieth century provided the first clear functional description of a preferential interatrial conduction pathway. This structure, eponymically named “Bachmann’s bundle”, plays a central role in normal atrial activation and in the pathophysiology of interatrial block and atrial arrhythmias.

As a young man, Bachmann served as a merchant sailor, crossing the Atlantic multiple times. He emigrated to the United States in 1902 and earned his medical degree at the top of his class from Jefferson Medical College in Philadelphia in 1907. He stayed at this Medical College as a demonstrator and physiologist. In 1910, he joined Emory University in Atlanta. Between 1917 -1918 he served as a medical officer in the US Army. He retired from Emory in 1947 and continued his private medical practice until his death in 1959.

On the personal side, Bachmann was a man of many talents: a polyglot, he was fluent in German, French, Spanish and English. He was a chef in his own right and occasionally worked as a chef in international hotels. In fact, he paid his tuition at Jefferson Medical College, working both as a chef and as a language tutor.

The intrinsic cardiac conduction system was a major focus of cardiovascular research in the late nineteenth and early twentieth centuries. The atrioventricular (AV) node was discovered and described by Sunao Tawara and Karl Albert Aschoff in 1906, and the sinoatrial node by Arthur Keith and Martin Flack in 1907.

While the connections that distribute the electrical impulse from the AV node to the ventricles were known through the works of Wilhelm His Jr, in 1893 and Jan Evangelista Purkinje in 1839, the mechanism by which electrical impulses spread between the atria remained uncertain.

In 1916 Bachmann published a paper titled “The Inter-Auricular Time Interval” in the American Journal of Physiology. Bachmann measured activation times between the right and left atria and demonstrated that interruption of a distinct anterior interatrial muscular band resulted in delayed left atrial activation. He concluded that this band constituted the principal route for rapid interatrial conduction.

Subsequent anatomical and electrophysiological studies confirmed the importance of the structure described by Bachmann, which came to bear his name. Bachmann’s bundle is now recognized as a key determinant of atrial activation patterns, and its dysfunction is associated with interatrial block, atrial fibrillation, and abnormal P-wave morphology. His work remains foundational in both basic cardiac anatomy and clinical electrophysiology.

Sources and references
1. Bachmann G. “The inter-auricular time interval”. Am J Physiol. 1916;41:309–320.
2. Hurst JW. “Profiles in Cardiology: Jean George Bachmann (1877–1959)”. Clin Cardiol. 1987;10:185–187.
3. Lemery R, Guiraudon G, Veinot JP. “Anatomic description of Bachmann’s bundle and its relation to the atrial septum”. Am J Cardiol. 2003;91:148–152.
4. "Remembering the canonical discoverers of the core components of the mammalian cardiac conduction system: Keith and Flack, Aschoff and Tawara, His, and Purkinje" Icilio Cavero and Henry Holzgrefe Advances in Physiology Education 2022 46:4, 549-579.
5. Knol WG, de Vos CB, Crijns HJGM, et al. “The Bachmann bundle and interatrial conduction” Heart Rhythm. 2019;16:127–133.
6. “Iatrogenic biatrial flutter. The role of the Bachmann’s bundle” Constán E.; García F., Linde, A.. Complejo Hospitalario de Jaén, Jaén. Spain
7. Keith A, Flack M. The form and nature of the muscular connections between the primary divisions of the vertebrate heart. J Anat Physiol 41: 172–189, 1907.


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NOTE:  In 2014  Pavlos Plessas presented the compelling theory that Andreas Vesalius died in 1564 from scurvy on the island of Zakynthos. With his permission his original article entitled "Powerful indications that Vesalius died from scurvy" was published in this blog in 2016.

His theory was later challenged by Theo Dirix and Dr. Rudi Coninx in this same blog with the article "Did Andreas Vesalius really died from scurvy?". Pavlos Plessas' rebuttal to the latter article is published here from a letter to Theo Dirix.


...continued from: An answer regarding the death of Andreas Vesalius (1)...


Pavlos Plessas
Pavlos Plessas
Click on the image for author information

8. Echtius’ treatise was only published after his death in 1556

This is incorrect. Echtius was alive almost a decade after that and heard Boucherus describe Vesalius’ death with his own ears. The treatise was first published in 1564, the year of Vesalius’ death, albeit was wrongly attributed to Wierus.

9. Echtius believed scurvy was caused by a blocked spleen, leading to an excess of black bile

Echtius believed that an excess of black bile (melancholic humour) caused scurvy. He wrote that in addition to eating preserved foods and mouldy biscuit, and drinking foul water, the following conditions led to an excess of black bile: warm air, lack of sleep, hard manual work, anxiety and fevers. Each one individually could cause scurvy even if the diet was good . The reasons for Vesalius’ illness as indicated by the sources are: eating rotten biscuit, drinking corrupt water, hot weather and extreme worrying. Please compare with the list of causes given by Echtius in his treatise.

10. It is claimed that extreme fear and irrational behaviour … are well known early symptoms [Plessas]. This is not the case

I quote Rev. Richard Walter of the Anson expedition, who saw many of his shipmates die from scurvy: This disease is likewise usually attended with a strange dejection of spirits; and with shiverings, tremblings, and a disposition to be seized with the most dreadful terrors on the slightest accident (4). 


11. This (absence of extreme fear and irrational behaviour) is also the observation of one of the authors (RC) having observed scurvy patients in Ethiopian prisons

Did any of Dr. Coninx’s patients see other inmates die from scurvy? Did he ever observe one of his patients witness an accident? Were his patients evaluated by a psychiatrist? I would hazard the guess that the answer to all the questions is no. I choose to believe Rev. Richard Walter.

12. The Italian Pietro Bizzari based his account on what he had been told by an anonymous Venetian goldsmith

Bizzari’s account is not credible. It clashes with the accounts of three different people, who saw Vesalius’ grave in Santa Maria delle Grazie.

13. Metellus describes the symptoms of Vesalius’ illness

No, he does no such thing.

14. The possibility of rotten food as a cause of death on the ship is plausible

I hope this is not a suggestion that a great physician like Vesalius could not recognise the symptoms of food poisoning in others. If he did, it would have been possible to identify the particular source and he would not have fallen ill himself. Even if that was not possible they could have resorted to sharing the supplies of the crew, who had suffered no cases of illness. Surely it is best to be malnourished than risk death from food poisoning. In addition, had the cause of death been food poisoning, the sources would not have blamed Vesalius’ worrying for his illness. Finally, since the authors seem to agree that Metellus’ version of events is the most reliable, how is it possible for a man on the verge of death from food poisoning to be walking on the seashore of Zakynthos? Food poisoning as a cause of death is not plausible even though the sources claim the disease was somehow related to food and water shortage.

15. A 1971 study by Kinsman and Hood which allegedly claims that personality changes are amongst the first symptoms of scurvy

Why allegedly? I quote from the study: The personality changes occurred at an earlier stage of depletion than the psychomotor changes, which did not appear until obvious clinical scurvy was present (5). So the study does claim that personality changes are amongst the first symptoms of scurvy, the very first as a matter of fact. According to figure 3 of the study the MMPI T-scores started increasing when the level of Vitamin C in the body was at the equivalent of 761 mg. Clinical signs of scurvy became apparent only when the level went down to 300 mg. 

Article continued here: An answer regarding the death of Andreas Vesalius (3)

Sources:

1. "Voyages and Travels in the Levant in the Years 1749, 50, 51, 52" London 1766, p. 147
2. "Medicina Nautica: an Essay on the Diseases of Seamen" Volume III, London 1803, p. 387
3. "De magnis Hippocratis" Lienibus Libellus, Antwerp 1564, pp. 26a – 31b
4. A voyage round the world in the years MDCCXL, I, II, III, IV, 5th edition, London 1749, p. 101.
5. Robert A. Kinsman and James Hood, Some behavioral effects of ascorbic acid deficiency, The American Journal of Clinical Nutrition, April 1971.
6. Fiona E. Harrison, Behavioural and neurochemical effects of scurvy in gulo knockout mice, Journal for Maritime Research, Volume 15, Issue 1, 2013.
7. Olivier Fain, Musculoskeletal manifestations of scurvy, Joint Bone Spine 72, 2005.
8. Wang et al, Effects of vitamin C and vitamin D administration on mood and distress in acutely hospitalized patients, the American Journal of Clinical Nutrition, 2013.