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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Acute pericarditis | 2/3 | https://en.wikipedia.org/wiki/Acute_pericarditis | reference | science, encyclopedia | 2026-05-05T07:25:45.765948+00:00 | kb-cron |
stage 1 -- diffuse, positive, ST elevations with reciprocal ST depression in aVR and V1. Elevation of PR segment in aVR and depression of PR in other leads especially left heart V5, V6 leads indicates atrial injury. stage 2 -- normalization of ST and PR deviations stage 3 -- diffuse T wave inversions (may not be present in all patients) stage 4 -- EKG becomes normal OR T waves may be indefinitely inverted The two most common clinical conditions where ECG findings may mimic pericarditis are acute myocardial infarction (AMI) and generalized early repolarization. As opposed to pericarditis, AMI usually causes localized convex ST-elevation usually associated with reciprocal ST-depression which may also be frequently accompanied by Q-waves, T-wave inversions (while ST is still elevated unlike pericarditis), arrhythmias and conduction abnormalities. In AMI, PR-depressions are rarely present. Early repolarization usually occurs in young males (age <40 years) and ECG changes are characterized by terminal R-S slurring, temporal stability of ST-deviations and J-height/ T-amplitude ratio in V5 and V6 of <25% as opposed to pericarditis where terminal R-S slurring is very uncommon and J-height/ T-amplitude ratio is ≥ 25%. Very rarely, ECG changes in hypothermia may mimic pericarditis, however differentiation can be helpful by a detailed history and presence of an Osborne wave in hypothermia. Another important diagnostic electrocardiographic sign in acute pericarditis is the Spodick sign. It signifies to the PR-depressions in a usual (but not always) association with downsloping TP segment in patients with acute pericarditis and is present in up to 80% of the patients affected with acute pericarditis. The sign is often best visualized in lead II and lateral precordial leads. In addition, Spodick's sign may also serve as an important distinguishing electrocardiographic tool between the acute pericarditis and acute coronary syndrome. The presence of a classical Spodick's sign is often a giveaway to the diagnosis. Rarely, electrical alternans may be seen, depending on the size of the effusion. A chest x-ray is usually normal in acute pericarditis but can reveal the presence of an enlarged heart if a pericardial effusion is present and is greater than 200 mL in volume. Conversely, patients with unexplained new onset cardiomegaly should always be worked up for acute pericarditis. An echocardiogram is typically normal in acute pericarditis but can reveal pericardial effusion, the presence of which supports the diagnosis, although its absence does not exclude the diagnosis.
== Differential Diagnoses == There are many causes of acute pericarditis, so the first step in differentiating is taking a good patient history to determine likely and unlikely causes of acute pericarditis. To diagnose acute idiopathic pericarditis, one must rule out all other causes of acute pericarditis (diagnosis of exclusion). Common diagnoses to rule out when considering acute idiopathic pericarditis include the following: Pericarditis secondary to post-cardiac injury: Differentiate this from acute idiopathic pericarditis by timing. If the pericarditis results a few days or weeks post acute myocardial infarction, trauma to the chest wall, cardiac surgery or other cardiac perforation causes pericarditis secondary to post-cardiac injury is most likely the diagnosis. Pericarditis secondary autoimmune disease: Differentiate idiopathic pericarditis from common autoimmune diseases that present with pericarditis as just one of many complications. This list includes, systemic lupus erythematosus, rheumatoid arthritis, scleroderma, dermatomyositis, polymyositis, mixed connective tissue disease, vasculitis, Inflammatory bowel disease, sarcoidosis, Behçet's disease, Still disease, Immunoglobulin G4-related diseases, Erheim-Chester disease, polyarteritis nodosa, etc. Can be done by evaluating labs such as ANA, ESR, anti-rheumatoid factor, Anti-SSA/Ro, Anti-SSB/La, and p-ANCA/c-ANCA and so on Pericarditis secondary to drug toxicity: Pericarditis can result from the following medications: Procainamide, isoniazid, hydralazine, and cyclosporine. Pericarditis secondary to metabolic derangements: Differentiate pericarditis from causes resulting from both excretion of waste, such as uremia (dialysis associated) as well as from endocrine function including hyperthyroidism, hypothyroidism, cholesterol and anorexia. This can be obtained from a basic CMP, TSH and T4 levels. Pericarditis secondary to infection: Differentiate between viral, bacterial, fungal, and/or protozoal. Evaluate if the patient has a fever, chills, septicemia or any other evidence of infection. Pericarditis secondary to malignancy: Differentiate the result of acute pericarditis arising from invasion/activation of the immune system from a tumor such as malignant melanoma, lymphoma, leukemia, or solid tumors. If a pericardial effusion is present, malignant cells are often found in the pericardial fluid.
== Treatment == Patients with uncomplicated acute pericarditis can generally be treated and followed up in an outpatient clinic. However, those with high risk factors for developing complications (see above) will need to be admitted to an inpatient service, most likely an ICU setting. High risk patients include the following:
subacute onset high fever (> 100.4 F/38 C) and leukocytosis development of cardiac tamponade large pericardial effusion (echo-free space > 20 mm) resistant to NSAID treatment immunocompromised history of oral anticoagulation therapy acute trauma failure to respond to seven days of NSAID treatment Pericardiocentesis is a procedure whereby the fluid in a pericardial effusion is removed through a needle. It is performed under the following conditions: