a 72-year - old woman was admitted to the emergency department because of chest pain .
twelve - lead electrocardiogram ( ecg ) revealed sinus rhythm ( 92  bpm ) with diffuse st - segment depression ( involving eight leads ) associated with st - segment elevation in lead avr ( fig .
, ecg showed rightward mean frontal plane qrs - axis and r - wave dominance with pure r waves in leads v1v3 suggesting right ventricular pressure or volume overload .
the patient had no history of chronic obstructive pulmonary disease , rheumatic valvular disease , or other conditions indicating right ventricular pathology .
cardiac enzyme levels were elevated : creatine kinase ( ck)-mb at 7.9  ng / ml ( 0.66.3  ng / ml ) and troponin i at 0.79  ng / ml ( 00.04  ng / ml ) .
since the elevated levels of the cardiac enzymes and ecg changes indicated left main coronary artery or threevessel disease , coronary angiography was performed .
bedside echocardiography showed right ventricular enlargement with a normal left ventricular ejection fraction ( 60% ) .
computed tomography of the chest was performed because of suspicion of acute pulmonary embolism ( ape ) , and it revealed a thrombus in the right pulmonary artery ( fig .
therefore , thrombolytic therapy ( alteplase ) was started , and the patient was discharged six days after admission .
clinical symptoms may be similar in patients with acute coronary syndrome ( acs ) and ape , and biochemical markers of myocardial necrosis may be elevated in both diseases .
in addition to the medical history and clinical and laboratory findings , 12-lead ecg is important , but has some limitations in the differential diagnosis of acs and pe .
ecg changes suggestive of myocardial ischemia were observed in 70% of patients with ape , and predicted worse progression and 30-day mortality , .
diffuse st - segment depressions in more than six leads associated with st - segment elevation in avr lead has been associated with left main , left main equivalent , or severe threevessel disease .
st - segment elevation in lead avr may also occur in ape patients , probably as an expression of right ventricular overload or right ventricular ischemia .
it is associated with poor prognosis , . a similar case of ape with diffuse st - segment depressions in more than six leads associated with st - segment elevation in avr lead
emergency physicians , cardiologists , and internists should be aware of the ecg findings of ape mimicking acs .
the authors have no commercial associations or sources of support that might pose a conflict of interest .
all authors have made substantive contributions to the study , and all authors endorse the data and conclusions .
 acute pulmonary embolism ( pe ) is a frequent life - threatening condition in emergency departments . 
 careful diagnosis is important , and different diagnostic tests such as electrocardiogram ( ecg ) , biochemical markers , echocardiogram , and computed tomography are required . 
 although ecg is a cheap and rapid diagnostic test for pulmonary embolism , it has some limitations in the differential diagnosis of acute coronary syndrome and acute pe . 
 herein , we report ecg results of a patient diagnosed with acute pe mimicking acute coronary syndrome . 
Case presentation
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