Wavy ECG gestures that make our heart to beat

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We all live, without skipping a heart-beat. These are more than 25 billion beats over a life-time. Each of these beats means that our heart muscles have had a powerful squeeze, pours blood to all our nooks and corners. But what makes our heart beat ? This enigma was settled in early 1900s, when we discovered the disciplined signals in our hearts. We are able to record these signals from the surface of our body. This is electrocardiograph, or ECG as we know it. Today this signal-graph has traversed from medical books to a much common use. We use ECG to indicate life.

ECG in a 1994 postage stamp from Denmark. The stamp is about Heart association. ECG has waves, that go up and down in a repetitive sequence.
What do these waves mean ?

These signals, are like an orchestra-conductor. These wavy signals, lead to a sequence of heart muscle-squeezes. This sequence makes blood move from the chambers of the heart, to the great vessel aorta. Aorta is like a hose-pipe which branches into our blood vessels. Together, heart and blood vessels form our circulatory system. This system is powerfully shown in various postage stamps.

A postage stamp from Burma, 1972 shows great vessels branching out from heart. The curved looped one is aorta, and the the straight vessel that passes through the loop with multiple branches is pulmonary artery. Aorta supplies blood to our body, and pulmonary artery to the lungs.
Japan in 1972 issued a postage stamp with a similar heart design.
Who discovered these waves ?

While by late 19th century, we knew that heart produces some electrical signals, there was no easy way to record these. In 1903, Willem Einthoven, a dutch physiologist was able to record these waves on the surface of our body using a galvanometer. He was awarded Nobel Prize for this work in 1924.

In 1993, Netherlands issued a set of three postage stamps on its Nobel Laureates. First one is van der waals, who gave us laws of gasses, second one is Einthoven who discovered heart waves, and third one is Eijekman who discovered vitamins.
W Einthoven, in this 1993 postage stamp set. ECG waves are shown on his forehead, Please note that these are labelled with a different alphabets.

It is a mystery, why Einthoven labelled these waves as PQRST, and not ABCDE. In fact, the first electrical recording of the heart was done by Lippmann in 1887. He had labelled two waves he found as V1 and V2. Initially Einthoven labelled these waves as A and B. However later, he identified another wave, which he labelled as P. This sequence was odd, so in the next version of his drawings, he relabelled all waves as PQRST, and later added a U wave. Probably Einthoven was influenced by convention in geometry, where the two points connecting a line are P and Q.

ECG tracing on this Postage stamp from Israel (1968). Please note that sequence of waves is repetitive. An ECG recording machine is in the foreground. In this set of stamps, ECG machine was listed as a key export of Israel.
Where do these waves come from ?

The ECG waves that are recorded on the body surface, reflect electrical action, that happens inside the cells in the heart. Different cells as well as elements have a variable electric signal wave pattern.

A postage stamp from Bulgaria (1994) shows an electric waveform. This image is representation of photoelectric state of matter, as described by a Bulgarian Scientist Georgi Nadzhakov in 1931.

ECG is also such a waveform from the conduction system of our heart. Electrical wave is followed by the muscle action. Muscle action leads to sounds. So, these wavy gestures from the conduction system of the heart, are a cause of our heart beats.

A 1994 postage stamp from Bulgaria, illustrates concept of signal and action. The first tracing is of the electric signals, and the next tracing is of the heart sounds. The electrical event in the first one precedes action in the second wave by a tiny fraction of a second.
Heart sounds have two major components S1, S2 and other minor sounds S3, S4. These sounds are recorded by phono-cardiographs. In 1972, a Bulgarian cardiologist Ivan Mitev discovered another minor heart sound (sixth tone), shown with an arrow in this stamp.
Wavy gestures in postage stamps

Postage stamps and first day covers have represented these wavy gestures with a fair degree of accuracy. Some of these depictions are of abnormal waveforms, and others are just a gibberish. Lets take a peek.

There is a wavy ECG in a monitor behind the patient in the postage stamp. This first day cover is from a 1972 postage stamp from Austria.
The waveform in the Israel stamp (1968) is a normal tracing. The waves in the stamp from Austria (1972) and Netherlands (1992) are patterns found in a heart disease.
This 1972 postage stamp from Senegal also has a ECG tracing in the background. While the graph paper is fine, the first wave-sequence is different from the second one.
This first day cover and postage stamp from Belgium has an abnormal, waves, that are wide and quite bizzare. This can be a serious heart issue or maybe an artists imagination of a rhythm.
ECG tracing in this 1978 postage stamp from Belgium, shows an abnormal pattern. This pattern is seen in a hypertensive heart, this stamp tries to depict.
This two stamp set from Saudi Arabia (1992) has a ECG tracing, which is more wavy than usual. Such irregular waves are commonly seen in tracings that have an electrical interference with other appliances !!
A set of two stamps, Cyprus 1972, Heart and ECG tracing on a paper
First Aid day card, Issued on 14th Sept 2024, Bangalore. wavy outline in the background
ECG changed the way we treat heart diseases

Discovery of electric waves of the heart, and our ability to record them was not an isolated event. A few years after his initial discovery in 1903, Einthoven collaborated with Thomas Lewis. Between 1909 and 1912, Lewis could identify various disorders of rhythm. Amongst these was atrial fibrillation, ectopics and heart blocks. Lewis published first book of ECG in 1920. As per Einthoven’s admission, he would not have got a Nobel Prize in 1924, had Lewis not written this book. By 1925, when he revised his book, Lewis felt that there was nothing more to be discovered.

In contrast to the stamps from Saudi Arabia, these 1992 stamps from Brunei have only one tall wave. While this wave (QRS) is the most prominent feature of an ECG, it is flanked by two small ones on each side (P and T) that this stamp has missed. Third stamp in the set (below) also has the same pattern.
Brunei, set of three stamps, 1992

When we obtain an ECG, we place electrodes (paddles and knobs) on our limbs and chest. Combination of these electrodes gives us leads. While Lewis worked with a three lead ECG, and further advances increased the number of leads. In 1939 American cardiologist Franklin Wilson introduced six chest leads. Three years later in 1942, Goldberger added another three to give us a 12-lead ECG we all use today. Over next 20 years, power of ECG had grown as we discovered many new heart rhythm conditions.

ECG machines become lean

Gradually ECG recording devices have become smaller, and portable. This technology surge in 1980s further advanced its use. For years ECG interpretation was a naked eye affair. Gradually in 1990s we moved to an automated interpretation. These automated interpretation is loved by those, for whom these waves do-not make much of sense. On the other hand, physicians and cardiologists view these with contempt.

This postage stamp from Australia (1998), depicts an ECG tracing, with a pattern (elevation of a segment between QRS and T waves) seen with early heart attack. Today we obtain ECG in ambulances, to detect heart attacks even before we reach a hospital.

Today ECGs have spilled outside of clinics and hospitals. These have moved to ambulances, watches, and many other wearable devices. We now have devices that not only record the rhythm, but also automatically act on them. Such automated defibrillators are now common in high end public spaces. This is the first medical sphere where we can train machines to read and interpret these waves. Artificial intelligence is here to stay, and probably replace the naked eye ECG reading. Nonetheless, brains that can make sense of these waves with confidence, shall continue to bask in glory.

First day cover of the Cyprus Heart stamps (dated 11th April 1972)

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