Some ECG features suggest a more extensive and complicated disease. There have also been case reports of electrical alternans( 7) and ST segment elevation in lead aVR with ST segment depression in leads I and V4–V6.( 8) The most common presentation is that of sinus tachycardia.( 6) This occurs in response to the physiological demand for cardiac output with decreased left-sided stroke volume. 10%–25% of patients with PE have a completely normal ECG.( 5) The most well-known finding is the S1Q3T3 pattern, as seen in Case 1. There is a wide range of ECG features associated with PE. However, there is increasing interest in the prognostic use of ECG, as well as evidence to suggest that certain ECG findings can play a role in predicting which patients have a more complicated disease or worse prognosis, and hence require more invasive testing and earlier aggressive treatment. Although some ECG changes are common in PE, ECG changes alone are insufficient to make a reliable diagnosis of PE. The maintenance of a high level of suspicion is critical in a physician’s approach to the diagnosis of PE.( 4)Ībnormalities upon investigation include ECG findings, elevated D-dimer blood test, evidence of right heart strain or visualisation of the embolus on TTE and filling defects representative of PE on CT-PA. Having a high or intermediate probability on objective clinical assessment prompts the need for further diagnostic study, although a low probability does not exclude the diagnosis. It is important, however, to bear in mind that symptoms may be mild or even absent, especially in cases involving only the segmental pulmonary branches. In addition, signs of lower extremity deep venous thrombosis (DVT) may be present. Massive PE may be accompanied by acute right ventricular failure, manifested as elevated jugular venous pressure, a right-sided third heart sound and a parasternal lift. Signs include tachypnoea, tachycardia, rales, decreased breath sounds, an accentuated pulmonic component of the second heart sound and jugular venous distention. Symptoms suggestive of an acute PE include dyspnoea at rest or upon exertion, pleuritic chest pain, cough, orthopnoea, and calf or thigh pain or swelling. In a study of over 42 million deaths occurring in the United States within a 20-year period, almost 600,000 patients (approximately 1.5%) were diagnosed with PE, with PE being the presumed cause of death in 200,000 of the patients.( 2) In the local context, a study of three National Healthcare Group hospitals in 2006 estimated the population-based incidence of PE to be 15 per 100,000, with lower rates of venous thromboembolism among Asians compared to Caucasians and Eurasians.( 3)Īlthough it is important to diagnose and treat PE early, the clinical presentation of PE is known to be variable and nonspecific, rendering an accurate diagnosis difficult. According to the International Cooperative Pulmonary Embolism Registry, the mortality rate at three months was 15.3%.( 1) Survivors of the acute event may also have to contend with morbidity due to chronic thromboembolic pulmonary hypertension or post-thrombotic syndrome. Acute pulmonary embolism (PE) is a potentially fatal disorder with a high mortality rate.

Pe ecg findings