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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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During the last month I have been traveling in South America and Greece. I attended the Vesalius Continuum Meeting in Zakynthos, Greece. This meeting commemorates the 500th birthday of Andreas Vesalius Bruxellensis at the place where he died. The meeting, the island and the people I met were incredible, and I intend to write about this during this week.
I will start with an article in several chapters on "The presence of Andreas Vesalius on the island of Zakynthos" and will continue with articles and comments on several of the research papers and communications presented at this meeting. These will include:
• "The last month of Andreas Vesalius"
• "Did Andreas Vesalius die of scurvy?"
• "Where is Andreas Vesalius buried"
• "Did Andreas Vesalius shipwreck?"
I am in the process of editing the articles and the photographs... there are many!
I am glad to be back! Dr. Miranda
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In human anatomy the term [defect] means a gap, a space, or a hiatus. It must be clearly understood that the term [defect] does not necessarily mean "defective". There are many defects in the human body which are normal and not defective. An example would be the esophageal hiatus.
This is important to understand in the definition of "hernia" as the presence of a defect can lead to a herniation trough a normal gap in a layer of tissue. It could be argued that since normally there is no hernia, something must have happened to make the defect "defective".
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The medical term [protrusion] originates from the Latin word [protrudere]. It is formed by the prefix [pro-], meaning "forward", or "out - towards the front", an the root term [-trusion], meaning "to push" or "to thrust". To thrust or to push out or forward.
The term becomes relevant in the definition of hernia as one of the requirements of a hernia is the presence of an element or structure that protrudes through a superficial weakness of defect.
As a side note, with this information, look at the meaning of other words that include the suffix [-trusion]
• Intrusion: To push in
• Extrusion: To push out
•Obtrusion: To push against
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This is a medical suffix that originates from the Greek [tomos] which means "to cut" or "to open". The intention is that the opening or wound made will be closed or repaired as soon as practical. Applications of this suffix include:
• Tracheotomy: Opening of the trachea
• Laparotomy: Opening of the abdomen
• Sternotomy: Opening of the sternum
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UPDATED: Cachexia describes a condition where the patient is ill and malnourished. It originates from the Greek word [κακός], meaning "bad". The suffix -ia] denotes "condition". It is a "bad condition" and refers to a bad habitus (body). The term was adopted later in Latin. The term [cachexia] was first used in English in 1541 in a translation of Galen's "Therapeutyke". The adjective form is [cachectic].
The term [cachexia] is used to describe a patient that because of general malnutrition, a chronic disease, or cancer appears very thin, with extreme weight loss, muscular atrophy, and a general appearance of wasting.
Note: The links to Google Translate include an icon that will allow you to hear the Greek or Latin pronunciation of the word.
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UPDATED: The word [volvulus] arises from the Latin word [volvere], meaning "to twist" or "to roll". It refers to the rolling or twisting of a segment of the gastrointestinal (GI) tract enough to cause stenosis or stricture of the vessels supplying the GI segment. This can lead to ischemia and eventual necrosis or infarction of the organ. A volvulus will also cause blockage of the passage of food through the GI tract. The plural for [volvulus] is [volvuli].
A volvulus can occur anywhere the GI tract is intraperitoneal; that is, it has a mesentery or mesentery-like attachment that renders it mobile and therefore can allow it to twist. Most volvuli occur in the transverse and sigmoid colon, as well as the jejunum and ileum. The etiology of a volvulus is multiple, ranging from peristaltic hypermobility, congenital malrotation pathology of the GI tract, to internal hernias, either congenital or acquired.
In the accompanying image by Thorek (1938), the arrow indicates the location of a mesenteric defect, being the cause for an internal hernia and intestinal torsion or volvulus. For more information and images, you can read this 2011 article by Timpone, V.M. et al. on "Abdominal Twists and Turns: Part I, Gastrointestinal Tract Torsions With Pathologic Correlation"
Article image in the public domain. modified from Thorek, 1938 "Modern Surgical Technique"



