Liberal Arts Blog — Artificial heart valves, Implantable Pace Makers, and Implantable Defibrillators

John Muresianu
3 min readNov 11, 2020


Liberal Arts Blog — Wednesday is the Joy of Science, Engineering, and Technology Day

Today’s Topic — Artificial heart valves, Implantable Pace Makers, and Implantable Defibrillators

Hearts can fail in so many ways. Human ingenuity has come up with miraculous ways of saving some of them. Today, a few notes on three such devices. Experts — please chime in. Correct, elaborate, elucidate.

ARTIFICIAL HEART VALVES — fixing stenosis and regurgitation

1. Problems: “stenosis” of thickening of the valve or “regurgitation” (backward flow). There are four heart valves: mitral (left atrioventricular), tricuspid (right atrioventricular), pulmonary, and aortic.

2. Inventor: Charles Hufnagel (1916–1989). First implant: 1952.

3. Milestone: the bi-leaflet heart valve: 1977.

NB: more than three million prosthetic heart valves have been implanted since.


1. The sinoatrial node, located in the right atrium, is the heart’s natural pace maker. When it malfunctions, two forms of arrhythmia can result: too fast (tachychardia, that is above 100 beats per minute) and too slow bradychardia (under 60 beats per minute).

2. Cardiologists specialized in fixing rhythms are called electrophysiologists. (Potential source of confusion: an EP physician could be an Emergency Physician or or an Electrophysiologist).

3. Inventor of the implantable pacemaker: Wilson Greatbatch (1919–2011). A “humble tinkerer” (and engineer), invented the device in his barn, licensed it to Medtronic which became the world’s biggest manufacturer of implantable medical devices in the world. Today, globally, about 750.000 pacemakers are implanted per year (about 250,000 in the US).

NB: The first surgeon to implant a pacemaker was Ake Senning (1915–2000) at Karolinska University in Solna, Sweden with the help of Rune Elmqvist (1906–1996).


1. Sometimes, sudden cardiac death is the first sign of heart disease.

2. To prevent this Michel Mirowski, a Holocaust survivor from Poland, along with a team at Johns Hopkins, developed and implanted the first ICD in 1980.

3. Today, about 800,000 people in the US have ICDs, and the rate of implantation is about 10,000 per month.

Artificial heart valve

Charles A. Hufnagel

Mechanical Heart Valves — History


A brief history of cardiac pacing

Wilson Greatbatch, Inventor of Implantable Pacemaker, Dies at 92 (Published 2011)

Wilson Greatbatch

Rune Elmqvist

A link to the last three years of posts organized by theme:

PDF with headlines — Google Drive


Please share the coolest thing you learned this week related to science, engineering, or technology. Or, even better, the coolest or most important thing you learned in your life related to science and engineering.

This is your chance to make someone else’s day. Or to cement in your mind something that you might otherwise forget. Or to think more deeply about something dear to your heart. Continuity is key to depth of thought.



John Muresianu

Passionate about education, thinking citizenship, art, and passing bits on of wisdom of a long lifetime.