Ep 166 Pericarditis and Cardiac Tamponade

In this Part 1 of our two-part series on pericarditis and myocarditis, Anton is joined by Walter Himmel, EM doc at North York General and Paul Dorian cardiologist, researcher, and educator at St. Michael’s Hospital in Toronto (with a short visit from @ECG Cases Jesse McLaren). They answer questions such as: why should pericarditis be considered a diagnosis of exclusion? Which clinical features are most useful in the diagnosis of pericarditis? What are the most common pitfalls in the ECG interpretation of a patient suspected of pericarditis? What are the best ways to differentiate the ECG of pericarditis from that of MI and early repolarization? How is uncomplicated viral pericarditis treated differently compared to pericarditis of other etiologies? Why is it so important to include colchicine as part of the treatment of pericarditis? Which patients with pericarditis should be considered for admission? and many more... Podcast production, sound design & editing by Anton Helman Written Summary and blog post by Kate Dillon, edited by Anton Helman March, 2022 Cite this podcast as: Helman, A. Himmel, W. Dorian, P. Pericarditis and Cardiac Tamponade. Emergency Medicine Cases. March, 2022. https://emergencymedicinecases.com/pericarditis-cardiac-tamponade. Accessed [date] Go to part 2 of this 2-part podcast on pericarditis and myocarditis Pericarditis as a diagnosis of exclusion Pericarditis should be considered a diagnosis of exclusion, after ruling out the big chest pain killers (MI, PE, aortic dissection, esophageal rupture, and tension pneumothorax), because it can be easily confused with these more time-sensitive, deadly diagnoses. Avoid premature closure! The following features are suggestive of pericarditis, but none alone have good enough test characteristics to rule it in or out. Clinical features of pericarditis Pericarditis diagnostic criteria and evaluation The diagnosis of pericarditis requires 2/4 of the following criteria: * Chest pain – typically sharp, pleuritic, positional (>80- 90% of cases) * Pericardial rub on auscultation (<1/3rd of cases) * New widespread ST elevation or PR depression on ECG (up to 60% of cases) * New or worsening pericardial effusion (up to 60% of cases) Additional supportive findings: * Elevated inflammatory markers (CRP, ESR, WBC count) * Evidence of pericardial inflammation on imaging (contrast CT, cardiac MR) Diagnostic evaluation for pericarditis * Auscultate for friction rub (excellent specificity/poor sensitivity) * ECG (see below) * Ultrasound (see below) * CXR (enlarged cardiac silhouette if associated with large pericardial effusion) * WBC + diff - if very elevated consider bacterial cause such as TB and/or alternate diagnosis such as endocarditis * ESR/CRP - thought to be useful to support diagnosis, risk stratify, assess effectiveness of treatment (serial evaluations) and predict recurrence * Creatinine to asses for uremia as a cause * Troponin to help rule out ACS and myopericarditis Pearl: CRP it thought to be helpful in pericarditis diagnosis, risk stratification, assessing effectiveness of treatment through serial evaluations and predicting recurrence ECG in pericarditis - more than just diffuse ST elevation The 4 stages of ECG changes in pericarditis It is important to understand that the classic diffuse ST elevation/PR depression (stage 1) is only found in 60% of patients with pericarditis as patients may present to medical care...