Inverted T wave in V1 to V3, right ventricular strain, high Daniel ECG score and ST-T change were helpful (sensitivity 27.8 - 69.1%, specificity 65.9 - 94.9%, LR (+) 2.03 - 5.45, LR (-) 0.47 - 0.85) in the diagnosis of pulmonary embolism in all patents and in patients without pre-existence cardio-pulmonary disease.