What are the electrocardiogram (ECG) signs of pericarditis?

From the Guidelines

The ECG signs of pericarditis typically include diffuse ST segment elevation in multiple leads without reciprocal ST depression, PR segment depression, and eventual normalization of ST segments followed by T wave inversions in the recovery phase, as described in the 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guideline for the evaluation and diagnosis of chest pain 1. The ST elevation typically appears concave upward (saddle-shaped) and is most prominent in leads I, II, aVL, aVF, and V2-V6. Unlike myocardial infarction, the ST changes in pericarditis are widespread rather than localized to a specific coronary territory. Some key points to consider when interpreting ECG signs of pericarditis include:

• PR segment depression, particularly in lead II and PR elevation in lead aVR, reflects atrial involvement in the inflammatory process.
• The evolution of ECG changes in pericarditis follows four stages: initial ST elevation with PR depression, normalization of ST segments, T wave inversions, and finally resolution of all changes.
• These ECG findings result from the inflammatory process affecting the epicardial surface of the heart, causing current flow abnormalities that manifest as these characteristic patterns.
• It's essential to note that these changes may not all be present simultaneously, and some patients with pericarditis may have normal ECGs, as highlighted in the 2015 ESC guidelines for the diagnosis and management of pericardial diseases 1. The diagnosis of pericarditis should be based on a combination of clinical presentation, ECG findings, and other diagnostic tests, such as echocardiography and cardiac magnetic resonance imaging, as recommended in the 2015 ESC guidelines 1 and the 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guideline 1.

From the Research

ECG Signs of Pericarditis

• The ECG is a crucial diagnostic tool for pericarditis, often showing widespread ST-segment elevation or PR depression 2, 3, 4.
• However, these classic ECG patterns are only seen in less than 60% of patients with pericarditis 2.
• ECG changes in pericarditis can be temporally dynamic and evolve rapidly during the course of the disease 2.
• PR-segment depression with multilead ST-segment elevation and ST-segment depression in lead aVR are also characteristic ECG findings in acute pericarditis 3.
• To differentiate acute pericarditis from acute ST-elevation myocardial infarction, findings such as QRS widening and QT interval shortening in leads with ST-segment elevation can be helpful 3.

Types of ECG Changes

• Widespread ST-segment elevation is a common ECG change in pericarditis, occurring in about one-quarter of patients 5.
• PR-segment depression is another ECG finding that can be seen in pericarditis, particularly in leads DII, DIII, aVF, and V3-6 6.
• ECG changes may also reflect concurrent myocarditis, which should be ruled out in patients with pericarditis 5.

Differential Diagnosis

• Acute myocardial infarction can present with similar ECG changes to pericarditis, making differential diagnosis crucial 3, 4.
• Early repolarization can also mimic ECG changes of acute pericarditis, highlighting the need for accurate history, physical examination, and ECG interpretation 4.