High troponin I level following off label use: case reportAn 84-year-old woman developed high troponin I level following off label treatment with chloroquine for COVID-19 [route, dosage and outcome not stated; time to reaction onset not clearly stated].The woman, who had hypertension, was receiving amlodipine. Subsequently, she was admitted to ICU with COVID-19. She had anorexia, dyspnoea, fatigue, weakness, mild fever, myalgia and cough. She was diagnosed with COVID-19 pneumonia. A real-time PCR also confirmed COVID-19. She started receiving off-label treatment with chloroquine, vancomycin and atazanavir [alazanavir]. She also received naproxen. Her medical history was significant for prior coronary angiography due to dyspnoea of exertional FC2 which had been probably related to diastolic dysfunction. She also had an old left bundle branch block (LBBB). At current presentation, electrocardiography (ECG) was performed which demonstrated sinus tachycardia and old LBBB. Laboratory investigations revealed positive result for troponin I in two assessments. On 2 nd day of hospitalisation, quantitative troponin I was checked and was found to be high at 2136 ng/L. Transthoracic echocardiography (TTE) demonstrated normal left ventricular size in diastolic and systolic cycle, normal right ventricle size and right ventricle function, mild tricuspid valve regurgitation with normal left and right atriums size, normal systolic pulmonary pressure and no significant wall motion abnormality. On 3 rd day of hospitalisation, repeat TTE showed same findings without any changes. She was scheduled for a cardiac MRI. However, she died in afternoon of the 3 rd day of hospitalisation [cause of death not stated]. The high troponin I level was suspected to be due to chloroquine therapy and COVID-19.