Wednesday, January 7, 2015

Could that chest pain be Pericarditis?

Chest pain is, the pain of our existence in the ED (one of many). Pericarditis is one of the long list of possible etiologies and it's important we recognize it because the therapy is very different from other common causes of chest pain. So let's review the basics.

Chest pain is the presenting symptom in virtually all patients for whom a diagnosis of pericarditis would be considered. Although the differential diagnosis of chest pain is extensive, certain features point strongly to pericarditis, especially pleuritic pain that is relieved by sitting forward and that radiates to the trapezius ridge (the latter feature is virtually pathognomonic). Many patients have premonitory symptoms suggestive of a viral illness, and an abrupt onset is not unusual. Sinus tachycardia and low-grade fever are also common. The diagnosis of acute pericarditis is established when a patient has at least two of the following symptoms or signs: chest pain consistent with pericarditis, pericardial friction rub, typical ECG changes, or a pericardial effusion of more than trivial size. Because the rub and ECG findings may be transient, frequent auscultation and ECG recordings can be helpful in establishing the diagnosis.

The electrocardiographic signs of pericarditis are distinctive to the trained eye, but they can also be subtle. It is important to recognize that the fibrous tissue of the pericardium is electrically silent; therefore, the presence of electrocardiographic changes indicates a degree of myocarditis. There are some who suggest that the correct name should be myopericarditis. In any case, the "classic" EKG changes in pericarditis described are diffuse ST elevation in leads I, II, aVL, aVF & V1. Some myocarditis can occur specially in the atria causing an exaggerated atrial T wave and PR segment depression, which is seen only in viral pericarditis.

Some refer to the concave upwards ST elevation as the "smily face" of pericarditis compared with the"frown face" of STEMI.

Another EKG finding is the Spodick sign, which is a downsloping of the TP segment. When you see it and there are not other worrying findings, you may feel a bit more comfortable calling it pericarditis

Another example: 

Now, changes NOT seen in pericarditis that are worrisome: Q waves (specially if new), conduction abnormalities (BBB's, AVB's), T wave inversion following ST elevation, dysrhythmias and reciprocal ST depression. If you see any of this, you cannot call it pericarditis, at least not based on electrocardiographic findings.

Nonsteroidal antiinflammatory drugs (NSAIDs) have long been the mainstay of the initial treatment of acute pericarditis. The most commonly used agents are ibuprofen (600 to 800 mg every 6 to 8 hours), indomethacin (25 to 50 mg every 8 hours), and aspirin (2 to 4 g daily in divided doses). Patients receiving these drugs should also receive a proton pump inhibitor for gastric protection. On the basis of observational data from a relatively small number of patients with recurrent pericarditis, the European Society of Cardiology concluded in its 2004 guidelines that there was sufficient evidence to recommend colchicine combined with an NSAID for initial treatment of a first bout of pericarditis. More recently, evidence from the Investigation on Colchicine for Acute Pericarditis (ICAP) randomized clinical trial, involving patients with a first episode of pericarditis, strongly supported this recommendation. The optimal duration of treatment is uncertain. For colchicine, a 3-month course is reasonable on the basis of results from the ICAP trial. The usual duration of NSAID treatment, supported by expert opinion, is 1 to 2 weeks, with the actual duration driven by clinical response.

In 70 to 90% of patients, acute idiopathic pericarditis is self-limited, responds promptly to initial treatment, and completely resolves. In a small number of patients, probably less than 5%, the condition does not respond satisfactorily to initial treatment, and in 10 to 30% of patients, recurrences develop after a satisfactory initial response. Most patients have only one or two recurrences, but a small fraction (probably less than 5% of the total population with acute pericarditis) have multiple recurrences with considerable disability. Ultimately, recurrences cease in the majority of cases.

In Summary:
- Think pericarditis in the differential diagnosis of CP.
- EKG findings: Diffuse concave upwards STE, PR depression, downsloping TP segment (Spodick's sign) 
- Consider ischemia if there are Q waves, arrhythmias, conduction abnormalities, ST depression.
- If still not clear diagnosis, get an echo and look for pericardial effusion vs wall motion abnormalities.
- Labs are not particularly useful, but elevated trops indicate myocarditis and these patients should be admitted to monitor bed as they have increased risk for complications.
- NSAID's and ASA first line. Colchicine for prevent recurrence

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