Cardiac troponin I - release after severe sCorpion envenoming by Tityus serrulatus

Cupo, P., Hering, S.E.

Department of Pediatrics, Faculty of Medicine of Ribeirão Preto, University of São Paulo. 

Objectives: The objective of the present study was to determine the presence of cardiac injury in patients with severe scorpion envenoming by serial measurements of cardiac troponin I (TnI), currently considered the gold standard for diagnosis of acute myocardial infarction.

Patients and Methods: Eight children aged 2 to 9 years, with signs and symptoms of severe scorpion envenoming by Tityus serrulatus were studied. All patients were submitted to ECGs at admission, and every 12 hours on subsequent days after the sting. M-mode, two-dimensional color-flow Doppler transthoracic echocardiograms (ECHO) were performed in all patients at intervals after the sting. Blood was collected upon admission, before antivenom therapy and at intervals after the sting for the determination of glucose, CK-MB (activity and mass), AST, myoglobin, TnI, blood count, electrolytes, and circulating antigen venom.

Results: All patients showed clinical manifestations of cardiac dysfunction, with ECG and echocardiographic alterations and 5 developed pulmonary edema. CK-MB mass and myoglobin were elevated in all patients but one on admission and TnI was normal in all children, except for two patients  who arrived later. These values increased subsequently, followed by normalization within 4 to 5 days, with myoglobin being the first marker that returned to normal.

Conclusions: The detection of TnI in patients with severe scorpion envenoming, and the observed temporal pattern and serum levels meet the criteria established for the diagnosis of acute myocardial infarction. The rapid reversibility of cardiac dysfunction, together with the normalization of the enzymatic, ECG and echocardiographic data, indicates the occurrence of an acute myocardial lesion without underlying or associated coronary disease.

CORRESPONDENCE TO:

Palmira Cupo, Rua Adolfo Serra, 889, Ribeirão Preto, SP, CEP: 14025-520, Brasil, Email: pcupo@fmrp.usp.br