What is the frequency of misdiagnosed pericarditis?

From the Guidelines

The frequency of misdiagnosed pericarditis is estimated to be relatively high, with studies suggesting that approximately 30-50% of cases may be initially misdiagnosed. Pericarditis is commonly mistaken for other conditions with similar symptoms, particularly myocardial infarction (heart attack), pulmonary embolism, pneumonia, or gastroesophageal reflux disease. This high rate of misdiagnosis occurs because the cardinal symptom of pericarditis—chest pain—mimics other more common or life-threatening conditions. The diagnosis becomes particularly challenging when classic findings like pericardial friction rub (present in only 30% of cases) or typical ECG changes are absent, as noted in the 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guideline for the evaluation and diagnosis of chest pain 1.

Some key points to consider in the diagnosis of pericarditis include:

• The presentation of chest pain that is sharp, pleuritic, and which may be improved by sitting up or leaning forward, although in many instances such findings are not present 1.
• The presence of a pericardial friction rub, which may be audible in some cases, and widespread ST-elevation with PR depression on electrocardiogram, although changes are nonspecific and may be transient 1.
• The use of echocardiography, which can detect pericardial effusion and thickening, although a normal study does not exclude the diagnosis 1.
• The measurement of inflammatory markers, such as C-reactive protein and erythrocyte sedimentation rate, which can be helpful in monitoring the activity of the disease and efficacy of therapy 1.

Clinicians should maintain a high index of suspicion for pericarditis in patients presenting with pleuritic chest pain that worsens when lying flat and improves when sitting forward, especially in younger patients without traditional cardiovascular risk factors. Proper diagnosis requires a comprehensive approach including careful history taking, physical examination, ECG, echocardiography, and sometimes cardiac MRI or elevated inflammatory markers like C-reactive protein and erythrocyte sedimentation rate.

It is also important to note that the diagnosis and management of pericardial diseases have been outlined in guidelines, such as the 2015 ESC guidelines for the diagnosis and management of pericardial diseases, which recommend a first diagnostic evaluation with auscultation, ECG, transthoracic echocardiography, chest X-ray, and routine blood tests, including markers of inflammation 1.

From the Research

Frequency of Misdiagnosed Pericarditis

• The frequency of misdiagnosed pericarditis is not directly stated in the provided studies, however, it can be inferred that misdiagnosis may occur due to the non-specific symptoms of pericarditis, such as chest pain, which can be similar to other conditions 2.
• A study published in the Australian family physician journal in 2011 states that pericarditis is diagnosed in 5% of patients presenting to hospital emergency departments with chest pain in the absence of a myocardial infarction, suggesting that pericarditis may be underdiagnosed or misdiagnosed in some cases 2.
• Another study published in the American journal of case reports in 2017 highlights the importance of a high index of clinical suspicion for acute pericarditis, as the symptoms and signs associated with pericarditis are frequently missing, and diagnosis is often overlooked 3.
• The studies provided do not give a specific frequency of misdiagnosed pericarditis, but they do emphasize the importance of considering pericarditis in the differential diagnosis of patients presenting with chest pain, and the need for a thorough diagnostic workup to confirm the diagnosis 4, 5, 6.

Diagnostic Challenges

• The diagnosis of pericarditis can be challenging due to the non-specific symptoms and the similarity with other conditions, such as myocardial infarction 2.
• The use of electrocardiography, echocardiography, and chest X-ray can aid in the diagnosis of pericarditis, but these tests may not always be specific or sensitive enough to confirm the diagnosis 2, 6.
• The clinical presentation of pericarditis can vary, and some patients may not exhibit the typical symptoms of chest pain and fever, making diagnosis even more challenging 6.

Importance of Accurate Diagnosis

• Accurate diagnosis of pericarditis is crucial to ensure timely and effective treatment, and to prevent complications such as cardiac tamponade and constrictive pericarditis 2, 3.
• The use of aspirin, nonsteroidal anti-inflammatory drugs, and colchicine is the mainstay of treatment for pericarditis, but corticosteroids and immunosuppressive agents may be necessary in some cases 4, 5.
• The frequency of misdiagnosed pericarditis is not well established, but it is likely that some cases are misdiagnosed or underdiagnosed due to the challenges in diagnosis and the non-specific symptoms of the condition 2, 3, 6.