Downsloping TP segment seen as an early ECG manifestation in ~80% of patients with pericarditis, best visualised in leads II and the lateral precordial leads
ECG changes associated with Stage I pericarditis, first described by David H. Spodick in 1974. The sign remained relatively unevaluated until a recent retrospective analysis in 2020. Witting et al, considered an ECG to demonstrate Spodick’s sign when at least two leads had TP downsloping of at least 1 mm.
- Potential useful distinguishing ECG feature between acute pericarditis and ACS
- Witting found that Spodick’s sign occurred in 29% of patients with pericarditis and 5% of patients with STEMI (OR 5.9)
- PR depression alone can be a masquerader as it is seen in 12% of patients with STEMI
- A separate prospective study by Porela et al found that PR depression had a high sensitivity (88%) for myopericarditis but a low specificity
Differentiating STEMI from pericarditis
The most discriminating features remain as ST depression, ST elevation in lead III >II, and absence of PR depression. It is thus still recommended to look for features of STEMI first on the ECG with ST elevation:
- Search for ST depression (aside from leads aVR and V1)
- Look for ST elevation in III > II
- Search for horizontal or convex upward ST elevation
Following this, additional features such as Spodick’s sign can be reviewed to further differentiate the diagnosis of pericarditis.
- Sinus tachycardia
- Widespread concave STE and PR depression (I, II, III, aVF, V4-6).
- Reciprocal ST depression and PR elevation in V1 and aVR
- Spodick’s sign best visualised in lead II
- David H Spodick (1927-2019)
- Spodick DH. Diagnostic electrocardiographic sequences in acute pericarditis. Significance of PR segment and PR vector changes. Circulation. 1973 Sep;48(3):575-80.
- Spodick DH. Electrocardiogram in acute pericarditis. Distributions of morphologic and axial changes by stages. Am J Cardiol. 1974 Apr;33(4):470-4.
- Ginzton LE, Laks MM. The differential diagnosis of acute pericarditis from the normal variant: new electrocardiographic criteria. Circulation. 1982 May;65(5):1004-9.
- Makaryus JN, Makaryus AN, Boal B. Spodick’s sign. Am J Med. 2008 Aug;121(8):693-4.
- Makaryus JN et al. Diagnostic issues in the clinical management of pericarditis. Int J Clin Pract. 2010 Sep;64(10):1384-92.
- Chhabra L, Spodick DH. Ideal isoelectric reference segment in pericarditis: a suggested approach to a commonly prevailing clinical misconception. Cardiology. 2012;122(4):210-2.
- Maeba H. Isoelectric reference for pericarditis: TP may be better than PR. Cardiology. 2012;123(1):39-40
- Masek KP, Levis JT. ECG Diagnosis: Acute Pericarditis. Perm J. 2013 Fall; 17(4): e146.
- Chaubey VK. Spodick’s Sign: A Helpful Electrocardiographic Clue to the Diagnosis of Acute Pericarditis. Perm J. 2014 Winter; 18(1): e122.
- Smith SW. Diffuse ST Elevation and Chest Pain, What is it? 6 July 2015 Dr. Smith’s ECG Blog
- Witting MD et al. Evaluation of Spodick’s Sign and Other Electrocardiographic Findings as Indicators of STEMI and Pericarditis. J Emerg Med. 2020 Mar 25. pii: S0736-4679(20)30020-2.
- Wiesbauer F, Kühn P. ECG Yellow Belt online course: Become an ECG expert. Medmastery
- Wiesbauer F, Kühn P. ECG Blue Belt online course: Learn to diagnose any rhythm problem. Medmastery
- Rawshani A. Clinical ECG Interpretation ECG Waves
- Smith SW. Dr Smith’s ECG blog.
- Mattu A, Tabas JA, Brady WJ. Electrocardiography in Emergency, Acute, and Critical Care. 2e, 2019
- Brady WJ, Lipinski MJ et al. Electrocardiogram in Clinical Medicine. 1e, 2020
- Straus DG, Schocken DD. Marriott’s Practical Electrocardiography 13e, 2021
- Hampton J. The ECG Made Practical 7e, 2019
- Grauer K. ECG Pocket Brain (Expanded) 6e, 2014
- Brady WJ, Truwit JD. Critical Decisions in Emergency and Acute Care Electrocardiography 1e, 2009
- Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice: Adult and Pediatric 6e, 2008
- Mattu A, Brady W. ECG’s for the Emergency Physician Part I 1e, 2003 and Part II
- Chan TC. ECG in Emergency Medicine and Acute Care 1e, 2004
LITFL Further Reading
- ECG Library Basics – Waves, Intervals, Segments and Clinical Interpretation
- ECG A to Z by diagnosis – ECG interpretation in clinical context
- ECG Exigency and Cardiovascular Curveball – ECG Clinical Cases
- 100 ECG Quiz – Self-assessment tool for examination practice
- ECG Reference SITES and BOOKS – the best of the rest