Pericarditis: Clinical sciences

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Introduction0:00–0:50

Pericarditis is inflammation of pericardium, sometimes associated with the accumulation of fluid, known as a pericardial effusion.
The underlying inflammation might be due to viral infection, uremia, autoimmune disease, or after trauma, but regardless of cause, is associated with severe chest pain due to the pericardium’s abundant nerve supply.
Additionally, pericarditis may lead to the development of dangerous complications, such as pericardial effusion, which is characterized by accumulation of fluid around the heart; as well as cardiac tamponade, where the accumulated fluid compresses the heart.

Unstable patient0:50–4:23

So, if you suspect pericarditis or one of its complications, first you should perform an ABCDE assessment, to determine if your patient is unstable or stable.
If the patient is unstable, stabilize the airway, breathing, and circulation, which typically requires obtaining IV access and intubating the patient if you need to secure the airway.
Next, perform a focused history and physical examination. On physical exam be on the lookout for Beck triad, which includes hypotension, jugular venous distension, and muffled heart sounds.
Additionally, a physical exam might reveal pulsus paradoxus, which is when the systolic blood pressure drops with inspiration, and no audible pericardial friction rub.
All of these findings should lead you to suspect that a large pericardial effusion has resulted in cardiac tamponade, so your next step is to order an ECG and chest x-ray immediately to evaluate your suspicions.
Alternatively, if available, perform point of care ultrasound, or POCUS for short. ECG typically shows sinus tachycardia with low QRS voltage and electrical alternans, defined as beat-to-beat variation in the QRS amplitude.
This occurs as a result of swinging of the heart in the pericardial fluid, which can be seen with a large pericardial effusion.
On the other hand, chest x-ray might show an enlarged cardiac silhouette with clear lung fields. Finally, you can use POCUS to directly visualize pericardial effusion and detect collapse of the right sided cardiac chambers.
These findings confirm the diagnosis of pericardial effusion and cardiac tamponade. On the flip side, if you do not find any evidence of effusion or cardiac tamponade, then consider an alternate diagnosis.
Once you’ve confirmed that there’s a large pericardial effusion causing cardiac tamponade, provide treatment as quickly as possible.
Emergent treatment involves drainage of the pericardial effusion, either by pericardiocentesis, which can be performed at the bedside and guided by the use of POCUS, or the creation of a pericardial window, in which case you’ll call the surgical team for a consultation.
Now, here’s a clinical pearl! A large pericardial effusion resulting in cardiac tamponade ultimately impairs filling of the heart chambers such that cardiac output drops, causing obstructive shock.
So, in this case, use IV fluid administration with careful judgment, because you might increase preload and precipitate cardiovascular collapse.
Similarly, mechanical ventilation can increase intrathoracic pressure, further preventing the heart chambers from filling.
Therefore, the definitive treatment is to drain the effusion, allowing the heart to fill normally and the cardiac output to improve.
Next, let’s go back to the ABCDE assessment and take a look at stable patients. If your patient is stable, proceed with a focused history and physical examination, and order ECG and echocardiography.

Stable patient4:23–11:43

Next, use your findings to calculate a clinical criteria score that will help you confirm the diagnosis. The first clinical criteria that a patient will likely report is severe pleuritic chest pain, meaning it worsens with deep inspiration.
Additionally, they might report that pain is positional, usually improved by sitting up and worsened by lying down. The second clinical criteria, which you’ll find on auscultation of the chest, is a pericardial friction rub.
This is a scratchy or squeaking sound best heard at the left sternal border when your patient leans forward. The third one is the presence of ECG findings classic for pericarditis, which include diffuse ST segment elevations with or without associated PR segment depressions.
Finally, the last one includes echocardiography findings that reveal a new or worsening pericardial effusion. If none or only one of these criteria is met, then consider an alternative diagnosis.
On the other hand, 2 or more criteria confirm the diagnosis of pericarditis. While not needed to make the diagnosis of pericarditis, there are some laboratory and imaging studies that can provide supporting evidence and help guide clinical decisions.
Helpful lab studies include CBC and inflammatory markers, like ESR and CRP, while important imaging studies include a chest x-ray and transthoracic echocardiography, or TTE.
Elevated WBC count, ESR and CRP suggest an underlying systemic inflammatory condition. Now, here’s a high yield fact to keep in mind.
Both acute myocardial infarction, or MI, and acute pericarditis can present with chest pain, ST segment elevations on ECG, and elevated cardiac enzymes… So how can you differentiate them?
Let's start with chest pain. Chest pain from acute MI is anginal in nature, it gets worse with exertion and gets better with rest.
On the flip side, in pericarditis, chest pain does not change with exertion but does get better and worse with changes in body position.
Next let's look at the ST segment elevations on ECG. In acute MI, the elevations will be isolated to a few concordant leads, or leads that correspond to the same area of the heart, like the inferior leads, II, III, and aVF.
On the other hand, pericarditis causes ST elevation diffusely, in nonconcordant leads, and is often seen with PR interval depression.
Finally, cardiac enzymes in acute MI will be markedly elevated, while pericarditis is more likely to cause only minimal elevations.
Alright, now that you’ve diagnosed pericarditis, you can subdivide it into three main types: acute, recurrent, or chronic, based on the duration of symptoms.
The next step is to assess if the patient has had any previous episodes. If your patient had no previous symptoms or prior diagnosis of pericarditis, then they have acute pericarditis.
The most common causes include viral infection, uremia, or a recent myocardial infarction. You’ll want to make sure to treat the underlying cause, give NSAIDs, such as ibuprofen, indomethacin, or sometimes high-dose aspirin, in combination with colchicine.
Colchicine helps relieve the pain, but also decreases the chance of recurrence. Lifestyle modifications include avoidance of strenuous activity, as this may exacerbate symptoms.
On the other hand, if there is a history of pericarditis that resolved, but symptoms recur after 4 to 6 weeks, this suggests recurrent pericarditis, which is most common in idiopathic cases where the underlying cause was not identified.
Treatment is similar to acute pericarditis and includes NSAIDs, colchicine, and lifestyle modifications. However, those who fail to respond can be treated with glucocorticoids plus colchicine, or even triple therapy with glucocorticoids plus colchicine and aspirin; while those who can’t be treated with NSAIDs may get glucocorticoids plus colchicine.
Now, patients with recurrent pericarditis can receive additional therapy depending on their phenotype. Those with an inflammatory phenotype present with fever or evidence of systemic inflammation, like elevated WBC count, ESR, and CRP; and require treatment with IL-1 inhibitors, like rilonacept or anakinra.
On the other hand, a non-inflammatory phenotype, or those without elevated inflammatory markers or fever during the recurrent episode, require treatment with immunosuppressants, such as azathioprine or human IVIG.
If medical therapy fails to resolve the symptoms of recurrent pericarditis, consider surgical consultation for pericardiectomy.Finally, let’s discuss symptoms of pericarditis that persist longer than 6 months.
This is considered chronic pericarditis, which is most commonly caused by chronic inflammatory disorders, like autoimmune disease.
Here, treatment involves addressing the underlying cause, and again, consideration should be given for pericardiectomy.Now, here’s a high yield fact!
A clinical variant of chronic pericarditis is constrictive pericarditis, where fibrosis and scarring over time compromise the normal elasticity of the pericardium.
In these individuals, echocardiography or chest x-rays show thickening and calcification of the pericardium. Over time, the stiffened pericardium can lead to diastolic dysfunction and heart failure.
Treatment involves pericardiectomy. Alright, as a quick recap… If you suspect pericarditis, the first thing you should do is an ABCDE assessment, to determine if your patient is unstable or stable.

Review11:43–13:51

Unstable individuals typically present with large pericardial effusion and cardiac tamponade, which require prompt treatment with pericardiocentesis or pericardial window.
On the other hand, in stable individuals, use history and physical findings, ECG changes, and echocardiography to identify pericarditis.
If your patient meets at least 2 criteria, this confirms the diagnosis of pericarditis. Once the diagnosis is made, determine if it’s acute, recurrent, or chronic by assessing the patient’s history for previous episodes of pericarditis.
If no prior episodes are present, then the patient has acute pericarditis and treatment involves addressing the underlying cause with NSAIDs, colchicine, and lifestyle modifications.
If a patient has recurrent symptoms after a 4 to 6 week asymptomatic period, then the patient has recurrent pericarditis.
In this case, the treatment also includes NSAIDs, colchicine, and lifestyle modifications. Additionally, individuals with an inflammatory phenotype should receive IL-1 inhibitors, like rilonacept or anakinra.
On the flip side, patients with a non-inflammatory phenotype should get immunosuppressants, like azathioprine or human IVIG.
If the patient fails to respond to these therapies, consider pericardiectomy. Finally, patients with symptoms lasting longer than 6 months have chronic pericarditis.
Treatment involves treating the underlying cause