The importance of the differential diagnosis between pulmonary thromboembolism and acute coronary syndrome

Introduction: Pulmonary thromboembolism (PTE) occurs when there is an obstruction of one of the pulmonary arteries, thus preventing normal blood circulation. Pulmonary thromboembolism is often associated with several diseases. Clot formation results from hypercoagulability, blood stasis (decrease in blood flow) and damage to the endothelium of blood vessels, a set of changes known as Virchow 's triad . Objectives: Understand the role of the electrocardiogram in the diagnosis of pulmonary thromboembolism in an emergency setting. Clinical Case: A 79-year-old female patient with a personal history of chronic bronchitis, went to the Emergency Department due to dyspnea, chest pain, a non-productive cough and fatigue on small efforts. An ECG was performed which revealed sinus rhythm with deep inversion of the T wave in V1-V4. After contacting the cardiologist who confirmed the diagnosis of Coronary Syndrome in the subacute phase, in order to complement the diagnosis, a transthoracic echocardiogram was performed, which confirmed the existence of a rectified movement of the interventricular septum in relation to right overload and severe pulmonary hypertension, suggestive echocardiographic findings of pulmonary thromboembolism. Conclusion: In conclusion, although the S1Q3T3 pattern is the best known for diagnosing PTE, it is not always present on the ECG. Therefore, it is necessary to raise awareness of other electrocardiographic findings present in this condition.