'Reversible cardiomyopathy' in patients with severe scorpion envenoming by Tityus serrulatus: evolution of enzymatic, electrocardiographic and echocardiographic alterations.

Severe scorpion envenoming is characterized by cardiocirculatory failure which may lead to pulmonary oedema. These are the major causes of death among victims of scorpion stings. Involvement of the heart has been attributed to the massive release of catecholamines and/or to a direct toxic effect of the venom on cardiac fibres, while pulmonary oedema has been considered to be of cardiogenic or non-cardiogenic origin. We present here the clinical, laboratory, electrocardiographic and echocardiographic data of 12 victims of severe Tityus serrulatus stings. These patients had important echocardiographic evidence of moderate to severe left ventricular (LV) dysfunction with diffuse LV hypokinesia and reduced ejection fraction. Seven developed pulmonary oedema. The clinical course of all the patients was satisfactory and the laboratory, electrocardiographic and echocardiographic changes returned to normal, usually within 1 week of the sting. The important alterations detected by echocardiography as early as during the 1st few hours after the sting, taken together with the enzymatic and electrocardiographic data, confirm that LV dysfunction is responsible, either alone or in combination with other factors, for the cardiac insufficiency and pulmonary oedema encountered in scorpion envenoming.