An episode of atrial fibrillation can elevate troponin, but what would be the typical range of this elevation?
Atrial fibrillation is a serious heart rhythm disorder. Though for some patients it may not cause any symptoms, the bigger issue is that if untreated, it can cause pooling of blood in the heart.
This creates a big risk factor for an ischemic stroke — especially if the patient is over the age of 65 and has other stroke risk factors such as family history and smoking.
Atrial fibrillation can cause an elevation of troponin, an enzyme released by the heart when there is damage to the cardiac muscle.
“Some patients with atrial fibrillation (AF) develop a fast heart rate (rapid ventricular rate) in the setting of infection, bleeding or other medical conditions,” says Dr. Simon Dixon, chairman of cardiovascular medicine for Beaumont Health System in Michigan.
One such medical condition is coronary artery disease: buildup of fatty deposits inside the arteries.
When an episode of A-fib occurs, says Dr. Dixon, “the heart muscle needs greater blood supply to provide oxygen and glucose [blood sugar].
“At times, however, the ‘demand’ outstrips the ‘supply,’ resulting in damage to the muscle (especially on the inside wall of the heart, or subendocardial layer).
“Generally the troponin elevation in these cases is small, for example, 0.1-2.0 ng/mL (the upper limit for the normal range of troponin in our hospital is 0.06 ng/mL).”
This troponin range is called “indeterminate,” because it can have numerous causes other than an episode of atrial fibrillation, but this range isn’t high enough to arouse the suspicion for a heart attack.
Troponin elevation of unknown origin is far more common in elderly people, but should always be followed up. The younger a person is, the more significant an elevated result is.
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.