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Pericardial Effusion

Introduction:

Pericardial effusion ("fluid around the heart") is an abnormal accumulation of fluid in the pericardial cavity. The pericardium is a 2-part membrane surrounding the heart, the outer fibrous connective tissue membrane and an inner 2-layered serous membrane. The 2 layers of the serous membrane enclose the pericardial cavity (“space”) between them. This pericardial space contains a small amount of fluid, normally 15-60 mL in volume. The pericardium, specifically the pericardial fluid functions to lubricate the heart during each beat, stabilize anatomic position of the heart within the chest, and serves as a barrier to protect the heart from infection and inflammation in adjacent tissues and organs.

Because there is a limited amount of anatomic space in the pericardial cavity, fluid accumulation beyond the normal limit leads to an increased intrapericardial pressure which can negatively affect heart function. A pericardial effusion with enough pressure to adversely affect heart function is called cardiac tamponade. Pericardial effusion usually results from a disturbed equilibrium between the production and reabsorption of pericardial fluid or from a structural abnormality that allows fluid to enter the pericardial cavity.

Signs and Symptoms:

Pericardial effusion presentation varies from patient to patient. Some patients may be asymptomatic and the effusion may be an incidental finding on an exam. Others may present with chest pressure or pain, dyspnea/shortness of breath, and malaise (a general feeling of discomfort or uneasiness). Yet others with Cardiac tamponade, a life- threatening complication, may present with dyspnea, low blood pressure, weakness, restlessness, hyperventilation, discomfort with laying flat, dizziness, syncope, or even loss of consciousness.

Patient’s may also present with non-cardiac symptoms due to the enlarging pericardial effusion compressing nearby structures. Some examples are nausea and abdominal fullness, dysphagia and hiccups, due to compression of stomach, esophagus, and phrenic nerve respectively.

Physical Exam Findings

Patients with pericardial effusion with concern for cardiac tamponade may present with abnormal vitals and what's classically known as the Beck's Triad, which consists of hypotension (low blood pressure), jugular venous distension and distant heart sounds. Though these findings are classically taught, all three occur in only a minority of patients. More common findings are tachycardia and tachypnea. Another physical exam finding unique to pericardial effusion is dullness to percussion over the left subscapular area due to compression of the left lung base by the growing effusion. This phenomenon is known as Ewart's sign.

Patients presenting with cardiac tamponade may also be evaluated for pulsus paradoxus. Pulses paradoxus is a phenomenon in which systolic blood pressure drops by 10mmHg or more during inspiration. In cardiac tamponade, the pressure within the pericardium is significantly higher, hence decreasing the compliance of the chambers. During inspiration, right ventricle filling in increased, which causes the interventricular septum to bulge into the left ventricle, hence leading to reduced left ventricular filling and consequently reduced stroke volume and low systolic blood pressure.

Causes:

Inflammatory Causes:

1.    Infectious:


 * Viral: coxsackie A and B viruses, Hepatitis viruses, parvovirus B19


 * Bacterial: Mycobacterium (tuberculosis), gram positive cocci (Streptococcus, Staphylococcus), Mycoplasma, Neisseria (meningitides, gonorrhea), Coxiella burnetii
 * Fungal: Histoplasma, Candida
 * Protozoal: Echinococcus, Trichinosis, Toxoplasma

2.    Cardiac injury syndromes: Heart surgery (postpericardiotomy syndrome), post-myocardial infarction, coronary interventions (drug eluting stents)

3.    Cardiac inflammation: idiopathic pericarditis is the most common inflammatory cause of pericardial effusion in the United States.

4.    Autoimmune: lupus, rheumatoid arthritis, sjögren syndrome, scleroderma, dressler's syndrome, sarcoidosis

5.    Drug hypersensitivity/ side effects: Chemotherapy drugs (doxorubicin and cyclophosphamide), minoxidil

6.    Others: kidney failure, uremia

Non-Inflammatory Causes

1.    Neoplastic:


 * Primary tumor: the most common primary pericardial tumor is mesothelioma. Various imaging appearances such as solid and cystic components could be encountered on CT scan on those with mesothelioma . Other less common primary tumors are sarcoma, lymphoma, and primitive neuroectodermal tumour.


 * Secondary cancersL that have spread to the pericardium such as breast and lung cancer. Pericardial irregular thickening and/or nodularity, focal, or diffuse FDG uptake on PET scan and lack of preserved fat plane with an adjacent tumor are strongly suggestive of cancer spread from other parts of the body.

2.    Metabolic : hypothyroidism (myxedema coma), severe protein deficiency

3.    Traumatic : penetrating or blunt chest trauma, aortic dissection

4.    Reduced lymphatic drainage: congestive heart failure

Bibliography

Vakamudi S, Ho N, Cremer PC. Pericardial Effusions: Causes, Diagnosis, and Management. Prog Cardiovasc Dis. 2017 Jan-Feb;59(4):380-388. doi: 10.1016/j.pcad.2016.12.009. Epub 2017 Jan 4. PMID: 28062268. https://pubmed.ncbi.nlm.nih.gov/28062268/

Phelan, Dermot, et al. “Pericardial Disease .” Pericardial Disease, Cleveland Clinic, July 2015, www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/cardiology/pericardial-disease/.

Vogiatzidis, Konstantinos et al. “Physiology of pericardial fluid production and drainage.” Frontiers in physiology vol. 6 62. 18 Mar. 2015, doi:10.3389/fphys.2015.00062

Willner DA, Goyal A, Grigorova Y, et al. Pericardial Effusion. [Updated 2020 Aug 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK431089/