There’s a specific reason why an episode of atrial fibrillation can elevate troponin levels if you already have heart disease.
Troponin is a protein enzyme that leaks from heart muscle when that muscle sustains damage, such as from a heart attack or blunt chest trauma.
But an episode of atrial fibrillation–an abnormal heart rhythm–can also cause a leak of troponin, which of course, means that some damage to the cardiac tissue has occurred—but not nearly as much as would occur from a heart attack.
In a person whose only condition is A-fib, an episode of this cardiac arrhythmia won’t cause a rise in troponin.
But if someone has severe coronary artery disease, it can. In severe coronary artery disease (or “heart disease”), the arteries that supply blood to the heart are at least 70 percent blocked with plaque.
This leaves a small diameter through which blood gets through, and can cause symptoms, usually shortness of breath with only mild exertion, and/or chest pain.
Atrial Fibrillation + Heart Disease = Rise in Troponin
“Patients with coronary artery disease are more likely to have a troponin elevation because the blockage in the artery limits the ability of the heart to increase blood flow to the muscle during the AF episode,” says Dr. Simon Dixon, chairman of cardiovascular medicine for Beaumont Health System in Michigan.
When a patient’s troponin test result is elevated, another one should be taken several hours later to see if the numerical result is higher.
The test may be repeated a few more times to see when the number stops rising and starts coming down.
If the patient has not exhibited any sign of a heart attack, such as chest pain or pressure, clammy skin, nausea, jaw or arm pain, or shortness of breath, but they have atrial fibrillation, then the reason for the elevated troponin will not likely be that of a heart attack.
Dr. Dixon specializes in the treatment of acute and chronic coronary artery disease, with research focusing on pioneering treatments to save heart muscle in patients having heart attacks.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.