BackgroundElevated levels of cardiac enzymes in the blood are an indicator of ongoing
cardiac ischemia. Persistent tachycardia may lead to myocardial ischemia due to oxygen
supply-demand mismatch.ObjectivesWe sought to evaluate the probability of underlying
coronary artery disease (CAD) in patients with symptomatic supraventricular (SVT)
or ventricular tachyarrhythmias (VT) based on cardiac enzyme level fluctuation.Materials
and methodsTroponin I (TNI) levels were measured twice and coronary angiography was
also performed in patients without a history of cardiovascular disease and symptomatic
SVT or VT.ResultsOf the 114 (group A: CAD (n = 40), group B: no CAD (n = 74)) patients
eligible for the study, 34 patients in group A and 64 patients in group B had SVT,
while 6 patients in group A and 10 patients in group B had VT. All patients with underlying
CAD developed a significantly elevated TNI level compared to baseline, irrespective
of arrhythmia type (2.02 +/- 7.98 ng/ml vs. 5.64 +/- 13.38, p = 0.031). In patients
without CAD, TNI level was not significantly elevated compared to the baseline level,
irrespective of arrhythmia type (0.34 +/- 1.38 ng/ml vs. 0.48 +/- 1.48 ng/ml, p =
0.158). Most patients with normal TNI levels (46 of 47 patients; 98 %) had SVT. CAD
was present in 13 of 47 patients (27 %) with tachycardia, despite normal TNI levels.ConclusionsElevated
TNI levels are not helpful to discriminate between SVT and VT. An increase in TNI
level in repeated blood sampling can help identify patients with higher probability
of underlying CAD. Patients with VT demonstrated higher increases in TNI levels, compared
to patients with SVT.
