Natural course of ECG changes and the value of multimodality imaging in acute pericarditis

Background: ECG is the initial diagnostic tool that in combination with typical symptoms often raises the suspicion of pericarditis. Echocardiography remains the first-line imaging modality for assessment of pericardial diseases, particularly effusion/tamponade, constrictive physiology, and assessment of regional wall motion abnormalities as differential diagnoses. However, cardiac CT and cardiac magnetic resonance may be necessary in complicated cases, and to identify pericardial inflammation in specific settings (atypical presentation, new onset constriction), as well as myocardial involvement and monitoring the disease activity. Summary: In acute pericarditis, the most commonly used ECG criteria recommended by international guidelines are the widespread ST segment elevation or PR depression. However, the classic ECG pattern of widespread ST segment elevation or PR depression can be seen in less than 60% of patients. In addition, ECG changes are often temporally dynamic, evolve rapidly during the course of disease and may be influenced by a number of factors such as disease severity, time (stage) of presentation, degree of myocardial involvement, and the treatment initiated. Overall, temporal dynamic changes on ECG during acute pericarditis or myopericarditis have received limited attention. Hence, the aim of this brief clinical review is to increase awareness about the various ECG changes observed during the course of acute pericarditis. Key messages: ECG may be normal at presentation or for days after the index episode of chest pain, but serial ECGs can reveal specific patterns of temporally dynamic ST elevation in patients with pericarditis or myopericarditis, particularly during new episodes of chest pain.