Tachycardia-induced elevations in cardiac troponin in the absence of coronary artery disease.

Elevations in serum cardiac troponins are used to diagnose myocardial infarction caused by ischemic heart disease. Several other conditions result in elevated cardiac makers in the absence of significant coronary artery disease. While not commonly recognized elevations of troponin I (TNI) may be seen in patients with protracted arrhythmias. We describe three patients with prolonged tachycardia, heart rates of 200-260 beats per minute, who had elevated TNI (0.81-4.6 ng/ml) but no significant coronary artery disease. Two patients presented with ventricular tachycardia and one had an atrioventricular re-entrant tachycardia. None of the patients presented with symptomatic hypotension. Coronary angiography in all three patients did not demonstrate significant coronary artery disease. The finding of an elevated TNI level may be the result of tachycardia and not myocardial infarction related to ischemic heart disease.