8th March 2024

Pericardial Diseases

Pericardial Diseases

Background 

The pericardium is a fibroelastic covering consisting of visceral and parietal layers separated by the pericardial cavity. In a healthy adult, this cavity contains up to 50 ml of plasma ultrafiltrate. Inflammation of the pericardium is known as pericarditis and is most often caused by a viral infection. Diseases of the pericardium are encountered frequently in clinical practice with different aetiologies and presentations. Cardiac imaging plays a key role in diagnosis and can help guide decision making on management. Treatment includes non-steroidal anti-inflammatory drugs (NSAIDs), colchicine, and steroids where appropriate. Most patients with acute pericarditis with presumed viral or idiopathic cause have a good long-term prognosis.

Aetiology 

Causes of pericardial disease include infections, inflammation, neoplasms, vascular, congenital, and idiopathic causes: 

• Infectious: viral (enterovirus, adenovirus, HIV), bacterial (Staphylococcus, Pneumococcus, Salmonella), fungal (Mycobacterium tuberculosis) 
• Post myocardial infarction e.g., Dressler’s syndrome, post cardiac injury syndrome
• Trauma including iatrogenic e.g., post pericardiotomy
• Radiation therapy to the chest
• Drugs and toxins (Thiazides, Methyldopa, Amiodarone, Isoniazid, Doxorubicin, Procainamide)
• Metabolic (uraemia, dialysis-associated, myxoedema, ovarian hyperstimulation syndrome)
• Autoimmune conditions (SLE, RA, Bechet’s disease, collagen vascular disease)
• Systemic inflammatory conditions (IBD, Familial Mediterranean fever)
• Malignancy (lung and breast cancer, lymphoma, and mesothelioma) 

Clinical Presentation

Acute pericarditis can present in different ways, including flu-like symptoms of fever, myalgia, and dyspnoea, where viruses are the cause or with signs and symptoms related to the underlying disorder in patients with malignancy or autoimmune diseases. Typically, in acute pericarditis there are:

• Chest pain. This is sharp and pleuritic and may be improved by sitting up and leaning forward
• Pericardial friction rub. This is a superficial scratching sound best heard with the diaphragm of the stethoscope over the left sternal border
• ECG changes of widespread saddle shaped concave ST elevation with PR segment depression (see image below).

Image Source: Wikimedia Commons (2011). Pericarditis, Licensed under a creative commons licence. Available for free at: https://en.wikipedia.org/wiki/Pericarditis (Accessed: 26 January 2024).

Pericardial effusion

Significant pericardial effusion more than 300ml will be visible on chest x-ray and depicted by enlargement of the cardiac silhouette. The ECG findings of low voltage QRS complexes, tachycardia and electrical alternans is suggestive of a massive pericardial effusion. The patient may be asymptomatic or have symptoms related to the underlying cause. 

Malignancy and tuberculosis (particularly where TB is prevalent) should be considered in cases of hemorrhagic pericardial effusions. Other aetiologies for haemorrhagic effusions include percutaneous interventional procedures, post-pericardiotomy syndrome, complications of myocardial infarction (free wall rupture, thrombolysis), trauma and aortic dissection.  

Cardiac tamponade 

When severe, pleural effusion may lead to a cardiac tamponade presenting with signs and symptoms related to impaired cardiac function, hypotension, muffled heart sounds and jugular venous distension, collectively known as Beck’s triad. Other signs include tachycardia and pulsus paradoxus characterised by an exaggerated fall in BP >10mmHg on inspiration. Cardiac tamponade is a medical emergency and treatment is with pericardiocentesis.

Constrictive pericarditis

This can develop following chronic inflammation leading to pericardial non-compliance. This then restricts ventricular relaxation with the end-result of elevated, equalised diastolic pressures in all chambers. Conditions which may result in constrictive pericarditis include tuberculous pericardial effusion, post-cardiac surgery, radiation-induced, and idiopathic in some cases. Patients typically present with symptoms related to fluid overload (ranging from peripheral oedema to anasarca), symptoms secondary to diminished cardiac output in response to exertion (e.g., fatigability and dyspnoea on exertion) or at rest, or both. Kussmaul’s sign is an important examination finding characterised by an inspiratory increase in JVP due to inability of the right heart to distend sufficiently to accommodate inspiratory venous return. Auscultation may reveal a high-pitched pericardial knock along the left sternal border.  CXR showing pericardial calcification is pathognomonic in the presence of elevated JVP and heart failure.

Pericardial pathology consistent with constrictive pericarditis with a concomitant effusion is called effusive constrictive pericarditis. 

Diagnosis 

The full blood count may reveal elevated neutrophils and lymphocytes suggestive of bacterial and viral infections, respectively. Platelet levels should be known in case pericardiocentesis is required. C-reactive protein will be raised in infection/inflammation, whilst ESR may be elevated in autoimmune/inflammatory conditions. Cardiac imaging remains key in diagnosing pericardial diseases. Echocardiography is usually first line and provides useful diagnostic and even therapy-guided information. CMR and cardiac catheterisation can be used to further confirm the diagnosis.

The following are major echocardiographic signs of cardiac tamponade, which may not be seen in all patients due to other underlying conditions: 

• Diastolic collapse of the right atrium and right ventricle
• Respiratory variation in flow across mitral and tricuspid valves
• Inferior vena cava dilation with less than 50% inspiratory collapse

Management 

The goals of therapy are pain relief, resolution of inflammation (and, if present, pericardial effusion), and the prevention of recurrence. Patients should be instructed to restrict strenuous physical activity until symptoms have resolved and biomarkers have normalised.

For nearly all patients with acute idiopathic or viral pericarditis, the recommended therapy is combination therapy with colchicine plus NSAIDs. For patients with an identified cause other than viral infection, specific therapy appropriate to the underlying disorder is indicated. Glucocorticoids should be used for initial treatment of acute pericarditis only in patients with contraindications to NSAIDs or for specific indications (i.e., systemic inflammatory diseases, pregnancy, renal failure), and should be used at the lowest effective dose. 

Immunotherapy can be helpful in treating the underlying condition of patients with autoimmune or inflammatory conditions, which would, in turn, resolve the pericardial involvement. Examples include monoclonal antibodies such as abciximab, adalimumab and alemtuzumab.

References

• UpToDate: Acute pericarditis: Clinical presentation, diagnostic evaluation, and diagnosis.
• Marinella MA. Electrocardiographic manifestations and differential diagnosis of acute pericarditis. Am Fam Physician. 1998 Feb 15;57(4):699-704. PMID: 9490993.
• 2015 ESC guidelines for the diagnosis and management of pericardial diseases
• BMJ Best Medical Practice: Pericarditis
• Leib AD, Foris LA, Nguyen T, et al. Dressler Syndrome. [Updated 2021 Jul 18]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441988/