Pianopractice.org

7.5 Chest Pain from Piano Practice, Typing, Rogaine
By Chuan C. Chang
Re
There is apparently a large number of causes for chest pains, many of which resemble heart attacks in some respects; but fortunately, most of them are innocuous. However, I had been having occasional chest pains since the 1970s, several times a year, which resembled heart attack symptoms such as: pain on the left side, radiating up to my neck and spreading to the left under-arm. When I reported these pains to my doctor in the 1980s, he laughed and assured me that if they had been heart attacks, I would not be sitting there talking to him; I would have been dead a long time ago.
For a period around 1990, these pains came more frequently, together with some strange heart behavior that felt like heart palpitations or irregular heart beats, and occasional dizziness. After discussions of these symptoms with my doctor, he sent me to a cardiologist who applied all the standard tests for heart function, such as cardiograms, heart imaging, and stress tests. I passed them all with flying colors. Even so, the cardiologist gave me a diagnosis of angina (which turned out to be wrong), with recommendations to use heart medications that I may not need. I then made a pact with my company nurse that if I felt the pain again, I would rush to her for examination. The trouble was that the pain, though sometimes fairly strong, never lasted more than a few minutes so that it was gone before I got to the nurse's office. I felt more reassured when I accidentally discovered that if I drank cold water during the pain, it would subside in about 10 seconds. In addition, many years later, I discovered that many of my strange heart behavior was caused by Rogaine that I was using to regrow my thinning hair – these symptoms are listed in the Rogaine information sheets. So I was sure that the pain was not caused by heart attacks.
One day, in the 1990s, I got the pain again and I recalled that, several days previously, I had practiced the piano especially hard after not touching the keys for several months. So I thought – “could the pain be a delayed reaction to overworked piano muscles?” Practicing too hard without proper warm-ups is a known “no-no” in piano practice. This seemed not impossible, because I knew that over-worked muscles often become painful, not on the day of the over-work, but a day later. Ever since that day, I have been keeping track of my pains every time I either practiced hard at the piano or did an unusually large amount of typing. When the pains did come, they always came about three days after the over-work! I finally had a diagnosis! The long delay up to three days made this diagnosis so difficult. Mysteriously, soon after my self-diagnosis, the pain seldom returned.
Which over-worked muscle was causing the pain? Why did it not return in spite of my occasional intense piano practice in later years? Why was there such a long delay of three days? My speculation is that it is the diaphragm that is hurting. The pain stopped returning because I had researched piano practice methods and learned the importance of relaxation. Thus I learned to use relaxation, not only during piano practice, but for practically anything I did, such as typing or brushing my teeth. Apparently, I was practicing with a lot of stress before I learned to relax. The long delay of three days also seems explainable. Normally, over-worked muscles become painful after one day, especially after over-night sleep when the body repairs its muscles. The pain I felt was not a muscle pain but a spasm, like cramps, of the diaphragm. Such spasms can occur with any amount of delay. This explains why they lasted only a few minutes, and the spasms are apparently quieted down by drinking cold water, an action that might be relaxing to the diaphragm (the diaphragm must relax to allow swallowing). See section 7.6 for another activity-related pain.
Summary: stressed piano over-practice (or typing) can cause chest pain about three days after such practice, especially if you had not practiced at all for some time. Drinking cold water will quickly eliminate the pain. It is probably caused by diaphragm spasms. Most doctors and cardiologists may not be able to diagnose the cause of this pain.

Source: http://www.pianopractice.org/chestpain.pdf