Is Fluid Around The Heart Life-Threatening?

Overview

Pericardial effusion is an abnormal buildup of fluid in the pericardial cavity. The pericardium forms the double membrane, which surrounds the heart and encloses the pericardial cavity. ¹ Normally, the pericardial sac contains between 15-50 ml of pericardial fluid, providing essential lubrication, fixing the heart to the mediastinum and forming a protective barrier against infection, inflammation and acute chamber distension.¹ When the volume of fluid in the cavity exceeds the normal limit, it may lead to heart compression causing cardiac tamponade and obstructive shock.² 

Symptoms include shortness of breath, chest pressure, pain and malaise. Under this pressure, the heart chambers fail to relax between beats, causing a decrease in filling venous return and cardiac output.² Cardiac tamponade is a medical emergency, which requires prompt recognition and treatment to prevent cardiac arrest and cardiovascular collapse.² If not diagnosed and treated immediately, pericardial effusion can be fatal.² 

What Is Pericardial Effusion?

Pericardial effusion is the accumulation of excess fluid in the pericardial cavity surrounding the heart.³ The pericardial sac consists of a single-layered, thin visceral pericardium and thick parietal pericardium layer, which encloses a pericardial cavity containing pericardial fluid.³ The pericardial fluid, under normal conditions, provides lubrication during the heartbeat.¹ Injury or inflammation of the pericardium inhibits suitable drainage of fluid from the pericardial cavity, leading to additional fluid accumulation. This clinical condition is referred to as pericardial effusion and may lead to heart failure if left untreated.³ 

Symptoms Of Pericardial Effusion

The clinical presentation of pericardial effusion varies from one individual to the next. It often depends on the cause, the rate of accumulation and the size of the effusion.  It can also be influenced by the presence of haemodynamic (abnormal or unstable blood pressure) or pulmonary (deterioration in lung function) compromise.⁴ 

This variation in symptoms is on account of the varying rate of accumulation of the pericardial fluid.³ Acute accumulation can cause impaired cardiac filling and a decrease in cardiac output while chronic slow filling may lead to significant effusions which produce no significant haemodynamic effects.³ 

Common symptoms include:

• Chest pressure or pain
• Dyspnoea (difficult or laboured breathing)
• Shortness of breath and general discomfort³ 

Patients with cardiac tamponade may experience:

• Chest pain
• Palpitations
• Shortness of breath 

and in severe cases:

• Dizziness
• Syncope (temporary unconsciousness) 
• Altered mental status. 

Pericardial effusion also compresses nearby structures, presenting non-cardiac-related symptoms including:

• Nausea 
• Abdominal fullness
• Dysphagia (trouble swallowing)
• Hiccups.⁵ 

Causes Of Fluid Around The Heart

Injury or inflammation of the pericardium inhibits essential lymphatic drainage of the fluid from the pericardial cavity, which results in excess fluid accumulation.⁵ The cause is determined by a thorough history and physical examination. In general, pericardial effusions can be divided into two categories: inflammatory and noninflammatory.⁵

Inflammatory

• Infectious
  • Viral: Enteroviruses (Coxsackie B, echoviruses), adenovirus, herpesvirus (Epstein–Barr virus [EBV], cytomegalovirus [CMV], VZV [Varicella zoster virus]), parvovirus B19, HIV, hepatitis C virus (HCV).
  • Bacterial: Mycobacterium (tuberculosis, avium-intracellulare), gram-positive cocci (Streptococcus, Staphylococcus), mycoplasma, Neisseria (meningitides, gonorrhoea), Coxiella burnetii.
  • Fungal: Histoplasma species, toxoplasma species
  • Protozoal: Echinococcus, trichinosis, toxoplasma⁵
• Cardiac injury symptoms: post-pericardiotomy (heart surgery), post-myocardial infarction (Dressler syndrome), coronary interventions and post-electrophysiology.⁵
• Autoimmune: Systemic lupus erythematosus, Sjögren syndrome, rheumatoid arthritis, scleroderma, eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome), familial Mediterranean fever.⁵
• Uremic pericarditis⁵
• Drug hypersensitivity or side effects: Chemotherapy drugs (cyclophosphamide, doxorubicin), minoxidil⁵
• Other causes: Uremia, kidney failure⁵

Non-inflammatory

• Neoplastic: Primary tumours (mesothelioma, sarcoma), secondary tumours (lung and breast cancer, lymphoma)⁵
• Metabolic: Hypothyroidism (myxedema coma), severe protein deficiency
• Traumatic: Direct or indirect pericardial injury (aortic dissection, penetrating or blunt chest wall injury)⁵
• Reduced lymphatic drainage: Nephrotic syndrome, congestive heart failure.⁵

Outlook for Pericardial Effusion

Is Pericardial Effusion Life-Threatening?

The pericardium has limited elasticity, with around 100 to 150 ml of fluid sufficient to cause cardiac tamponade, but in chronic conditions, up to 2 litres of fluid can accumulate before an effusion results in cardiac tamponade.³  

This excess fluid accumulation increases the pressure in the pericardial sac, leading to heart compression, particularly on the right side of the heart due to the thinner wall.³ As a result, impaired diastolic filling of the right side of the heart causes congestion in the veins and reduced diastolic filling of the left ventricle.  This leads to a decrease in stroke volume.³ 

Stimulation by adrenaline occurs as a compensatory response to tachycardia and increased contractility to maintain cardiac output.³ However, blood pressure and cardiac output eventually decline.³ In addition, compression of the heart also limits systemic venous return, which impairs the filling of the right atrium and ventricle.² 

Complications

Cardiac tamponade requires prompt diagnosis and treatment to prevent cardiovascular collapse and cardiac arrest. Patients suspected of having cardiac tamponade need to be under medical supervision as their condition can deteriorate quickly. Complications include nearby vessel damage (including coronary vessel puncture, internal mammary vessels), right ventricle puncture or laceration of the liver. 

Patients with large pericardial effusions with an underlying ventricular dysfunction have a risk of developing pericardial decompression syndrome (PDS) after pericardiocentesis treatment.³ PDS is an infrequent but life-threatening condition following an uncomplicated pericardial fluid evacuation for cardiac tamponade.³

Treating Fluid Around The Heart

Small effusions without evidence of haemodynamic compromise are monitored carefully with echocardiography. In contrast, large effusions may receive diagnostic pericardiocentesis to evaluate the aetiology (the cause) or drain the fluid around the heart to provide symptomatic relief to patients.³ 

Effusions that have accumulated rapidly or grown to a size large enough to cause haemodynamic instability or collapse must be managed immediately.³ Techniques for drainage are predominantly surgical and include:

• Needle pericardiocentesis
• Percutaneous balloon pericardiotomy
• Emergent thoracotomy
• Anterior mini-thoracotomy
• Surgical pericardial window via the subxiphoid (window provides a path for fluid to be drained directly into the chest cavity, which prevents future cardiac tamponade)
• Video-assisted thoracoscopic surgery (VATS). 

Patients with pericardial tamponade are also given IV fluids and vasopressors (to increase the patient's systemic blood pressure and cardiac output). The treatment type is chosen based on the aetiology, size and location of the pericardial effusion, severity of heart impairment and clinical condition of the patient.³ 

When To Seek Medical Attention

Call 999 or seek immediate medical care if you feel prolonged chest pain, difficulty breathing, fatigue or unexpected fainting. Cardiac tamponade is a clinical emergency which requires prompt medical attention. It is important to consult your doctor at the earliest to rule out the possibility of cardiac tamponade. 

Summary

Pericardial effusion is a clinical condition in which excess fluid accumulates in the pericardial cavity as a result of inflammation, injury or reduction in lymphatic drainage. Pericardiocentesis is the primary treatment method for the safe drainage of excess fluid and to relieve pressure surrounding the heart. It is performed depending on the size and location of the effusion. The pericardial window treatment method is preferred in the case of malignancy or if percutaneous access is difficult (in the case of posterior pericardial effusion).⁵ Consult your doctor at the earliest for effective management and treatment of pericardial effusions.