DEAR DR. ROACH: I am a 77-year-old male who apparently suffered a case of food poisoning. I say apparently because no cause was ever discovered for the uncontrollable vomiting and diarrhea that lasted for a whole day and recurred briefly the following morning.
A trip to the emergency room involved many tests, but nothing turned up except a troponin level well over 0.04 ng/mL, which prompted an angiogram that didn’t reveal any problems with my heart. What else might have caused my high troponin level? — Anon.
ANSWER: A troponin level is a standard blood test usually used to evaluate patients for heart attacks. However, newer, highly sensitive assays have proven that tiny levels of troponin may be detected in nearly everybody.
A level above 0.04 ng/mL is often used as the cutoff for the “normal” range, but depending on the assay and population studied, a few healthy people may have levels above this. People with heart attacks may have troponin levels in the hundreds or thousands.
The higher the troponin level, the more muscle damage there is.
The fact that your coronary arteries don’t show any blockages is very good news. Other types of heart damage may also cause a high troponin level, including inflammation of the heart (myocarditis) and heart failure. Also, critical illnesses can cause high troponin levels (at much higher levels than you may have had) in people who don’t have heart blockages. (A median of 0.57 ng/mL was found in people with septic shock.)
I found a long list of reported causes behind elevated troponin levels, but gastroenteritis was not on the list. I suspect your body was working so hard to fight off the infection without enough fluid that your heart needed more oxygen-carrying blood than it got, leading to tiny amounts of injury to the heart muscle despite normal heart arteries. You can lose a lot of fluid with vomiting and diarrhea, and people at age 77 don’t have as much reserve as they did when they were younger.