Signs of myocardial ischemia on electrocardiogram correlate with elevated plasma cardiac troponin and right ventricular systolic dysfunction in acute pulmonary embolism.

BACKGROUND Plasma cardiac troponins (cTn) are frequently elevated in acute pulmonary embolism (APE). ST-segment abnormalities on electrocardiography are also commonly observed in APE patients. However, it has not been defined which ventricle is a potential source of cTn release. We assessed the potential relationship between electrocardiographic signs of myocardial ischemia, systolic dysfunction of both ventricles at echocardiography and cTn levels in APE. METHODS We evaluated 94 consecutive patients (42 male, 52 female, aged 63 +/- 19 years) with APE. On admission, blood samples were collected for cTnI or cTnT and standard 12-lead electrocardiogram was performed. The following signs of myocardial ischemia were analyzed: T-wave inversion [T (-)] and ST-depression or elevation (> or = 1 mV, at > or = 2 leads). The assessment of systolic function of both ventricles was performed by echocardiography. RESULTS In 33 (35%) patients, cTn exceeded the upper reference limit of our laboratory. The history of coronary artery disease (27% vs. 31%) and previous myocardial infarction (12% vs. 10%) did not differ in patients with elevated cTn [cTn (+)] and non-elevated cTn [cTn (-)]. In cTn (+) group T (-) or ST-depression were observed more frequently than in cTn (-) [32 (97%) vs. 46 (75%), p < 0.01]. However, both groups presented similar frequency of ST-elevation [7 (21%) vs. 11 (18%), p = NS). Interestingly, cTn levels correlated with the number of leads with T (-) or ST-depression (R = 0.30, p < 0.01). Moreover, in cTn (+) group right ventricular systolic dysfunction was more frequent [15 (54%) vs. 4 (7%), p = 0.0001], while left ventricle contractility abnormalities occurred similarly in both groups [3 (11%) vs. 8 (15%), p = NS]. CONCLUSIONS Signs of myocardial ischemia (ST-segment changes) on electrocardiography in APE correlate with an elevated cTn and with the impairment of right, but not left, ventricle systolic function at echocardiography.