A Descriptive Analysis of ED Diagnosed Acute Pericarditis
This study describes the assessment and management of acute pericarditis when diagnosed in a major tertiary hospital ED. While many of the clinical features, investigations and treatment of the disease are in keeping with current understanding, there are several findings which are not typical.
Chest pain was always almost present, the character and radiation of pain was often atypical for the classical description of pericardial disease. Chest pain was equally recorded as sharp in nature or as a different character including dull, heavy, tight or gripping pain that may more commonly be associated with cardiac ischaemia. Radiation to the trapezoid ridge was not directly described in any patient records, and even including all documented radiation of pain to the neck, shoulder or arm, only 15.6% (95% CI 10.4% to 22.1%) of patients had such symptoms. Clinicians should be aware that the classical stabbing retrosternal chest pain with radiation to the trapezoid ridge is not typical of most patients in this study. Pleuritic or retrosternal pain with positional changes was common and should perhaps be given greater weight than other pain features when evaluating patients for acute pericarditis.
Examination findings were unhelpful in the diagnosis of pericarditis, with no abnormal findings having a high sensitivity. The presence of a pericardial rub was documented in only 19 patients and had a low sensitivity although previous studies suggest high specificity for pericarditis.
Investigations were inconsistently, although all patients had an ECG, and most had white cell count, renal function, troponin and a chest x-ray performed. None of these investigations were sensitive for pericarditis, but abnormal ECG, chest x-ray or troponin were significantly associated with admission to hospital. Imazio and colleagues demonstrated a 32.2% occurrence of elevated troponin I in idiopathic pericarditis which correlated with the extent of myocardial injury, but did not demonstrate a negative prognostic association. Elevated inflammatory markers, white cell count, d-dimer or thyroid function tests were not independently associated with inpatient admission.
Risk factors for severe disease have been based on several studies, with the presence of one or more risk factors suggesting an indication for admission. In this current analysis of risk factors, data reflecting immunosuppression or coagulopathy were not collected so a direct comparison with Imazio is not possible. Patients with more than one risk factor were significantly more likely to be admitted, although patients with elevated troponin, white cell count and fever above 38 degrees were frequently discharged. This may represent unfamiliarity with risk factors for severe disease, or that some patients with these features that can be safely discharged based on clinical impression. Each of the described risk factors may not be regarded as being equally sinister. Some risk factors such as elevated JVP and hypotension, are more easily recognisable as serious clinical features, while fever, raised white cell count, representation or subacute onset may be considered benign or routinely expected characteristics.
Electrocardiography was performed universally in this study, as would be expected in patients presenting to the ED with chest pain syndromes. Typical ST elevation and PR depression were the most common findings although were not universal. PR segment elevation in aVR was seen in 27.4% (95% CI 21.0% to 34.6%) of cases and has been described previously as a ubiquitous characteristic of acute pericarditis. Of the three patients with a low voltage QRS suggesting pericardial effusion, none required emergent drainage. Only a small number of patients in our study had echocardiographic analysis, making it an unreliable criterion for the assessment of acute risk in this study. Of the 17 patients with a documented effusion, 13 were admitted. All patients with a wall motion abnormality were admitted.
The high percentage of patients treated with NSAIDs reflects conventional practice, but the low number of cases treated with colchicine (7.8% (95% CI 4.3% to 12.5%)) is at odds with evidence that colchicine in addition to NSAIDs reduces recurrence rates of pericarditis following a first presentation.
The wide variety of other drugs used by clinicians in our study may be due to initial diagnostic uncertainty in this patient group. Of note, however, three patients were treated with steroids despite good evidence that use of corticosteroids can favour recurrence.
This study describes the patients with an ED diagnosis of pericarditis, and does not capture patients who were not diagnosed in ED but subsequently diagnosed with pericarditis. The lack of gold standard diagnostic criteria is also problematic, particularly in those patients with an ED diagnosis of pericarditis who may have subsequently had a different diagnosis. This was probably the case for those patients with pneumothorax or pneumomediastinum on review of their chest x-rays. This may also have been the case in patients with a wall motion abnormality on echocardiography, indicating a potential diagnosis of myocardial infarction with or without acute pericarditis.
As with any retrospective chart review, there are numerous methodological issues that limit our ability to draw conclusions from this study. The primary obstacle faced was the often poor and incomplete documentation in the charts of all aspects of patient presentations. The reported agreement between data extractors suggests a high level of accuracy in data extraction.
The use of EDIS to retrieve data also has inherent problems. The exit diagnosis is frequently entered by clerical staff, and may be erroneous if medical documentation in the notes is not adequate. In addition, patients diagnosed with pericardial effusion or tamponade may have had acute pericarditis as their underlying problem, but did not have this diagnosis entered into the EDIS database.
Discussion
This study describes the assessment and management of acute pericarditis when diagnosed in a major tertiary hospital ED. While many of the clinical features, investigations and treatment of the disease are in keeping with current understanding, there are several findings which are not typical.
Chest pain was always almost present, the character and radiation of pain was often atypical for the classical description of pericardial disease. Chest pain was equally recorded as sharp in nature or as a different character including dull, heavy, tight or gripping pain that may more commonly be associated with cardiac ischaemia. Radiation to the trapezoid ridge was not directly described in any patient records, and even including all documented radiation of pain to the neck, shoulder or arm, only 15.6% (95% CI 10.4% to 22.1%) of patients had such symptoms. Clinicians should be aware that the classical stabbing retrosternal chest pain with radiation to the trapezoid ridge is not typical of most patients in this study. Pleuritic or retrosternal pain with positional changes was common and should perhaps be given greater weight than other pain features when evaluating patients for acute pericarditis.
Examination findings were unhelpful in the diagnosis of pericarditis, with no abnormal findings having a high sensitivity. The presence of a pericardial rub was documented in only 19 patients and had a low sensitivity although previous studies suggest high specificity for pericarditis.
Investigations were inconsistently, although all patients had an ECG, and most had white cell count, renal function, troponin and a chest x-ray performed. None of these investigations were sensitive for pericarditis, but abnormal ECG, chest x-ray or troponin were significantly associated with admission to hospital. Imazio and colleagues demonstrated a 32.2% occurrence of elevated troponin I in idiopathic pericarditis which correlated with the extent of myocardial injury, but did not demonstrate a negative prognostic association. Elevated inflammatory markers, white cell count, d-dimer or thyroid function tests were not independently associated with inpatient admission.
Risk factors for severe disease have been based on several studies, with the presence of one or more risk factors suggesting an indication for admission. In this current analysis of risk factors, data reflecting immunosuppression or coagulopathy were not collected so a direct comparison with Imazio is not possible. Patients with more than one risk factor were significantly more likely to be admitted, although patients with elevated troponin, white cell count and fever above 38 degrees were frequently discharged. This may represent unfamiliarity with risk factors for severe disease, or that some patients with these features that can be safely discharged based on clinical impression. Each of the described risk factors may not be regarded as being equally sinister. Some risk factors such as elevated JVP and hypotension, are more easily recognisable as serious clinical features, while fever, raised white cell count, representation or subacute onset may be considered benign or routinely expected characteristics.
Electrocardiography was performed universally in this study, as would be expected in patients presenting to the ED with chest pain syndromes. Typical ST elevation and PR depression were the most common findings although were not universal. PR segment elevation in aVR was seen in 27.4% (95% CI 21.0% to 34.6%) of cases and has been described previously as a ubiquitous characteristic of acute pericarditis. Of the three patients with a low voltage QRS suggesting pericardial effusion, none required emergent drainage. Only a small number of patients in our study had echocardiographic analysis, making it an unreliable criterion for the assessment of acute risk in this study. Of the 17 patients with a documented effusion, 13 were admitted. All patients with a wall motion abnormality were admitted.
The high percentage of patients treated with NSAIDs reflects conventional practice, but the low number of cases treated with colchicine (7.8% (95% CI 4.3% to 12.5%)) is at odds with evidence that colchicine in addition to NSAIDs reduces recurrence rates of pericarditis following a first presentation.
The wide variety of other drugs used by clinicians in our study may be due to initial diagnostic uncertainty in this patient group. Of note, however, three patients were treated with steroids despite good evidence that use of corticosteroids can favour recurrence.
Limitations
This study describes the patients with an ED diagnosis of pericarditis, and does not capture patients who were not diagnosed in ED but subsequently diagnosed with pericarditis. The lack of gold standard diagnostic criteria is also problematic, particularly in those patients with an ED diagnosis of pericarditis who may have subsequently had a different diagnosis. This was probably the case for those patients with pneumothorax or pneumomediastinum on review of their chest x-rays. This may also have been the case in patients with a wall motion abnormality on echocardiography, indicating a potential diagnosis of myocardial infarction with or without acute pericarditis.
As with any retrospective chart review, there are numerous methodological issues that limit our ability to draw conclusions from this study. The primary obstacle faced was the often poor and incomplete documentation in the charts of all aspects of patient presentations. The reported agreement between data extractors suggests a high level of accuracy in data extraction.
The use of EDIS to retrieve data also has inherent problems. The exit diagnosis is frequently entered by clerical staff, and may be erroneous if medical documentation in the notes is not adequate. In addition, patients diagnosed with pericardial effusion or tamponade may have had acute pericarditis as their underlying problem, but did not have this diagnosis entered into the EDIS database.
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