“Water around the heart,” or pericardial effusion, is an abnormal accumulation of fluid within the pericardial sac. This double-layered membrane surrounds and protects the heart, normally containing a small amount of fluid for smooth cardiac movement. Excess fluid in this space can impair heart function.
Inflammation and Infection as Triggers
Inflammation of the pericardium, known as pericarditis, is a common cause of fluid buildup. This inflammation often results from infections.
Viral infections are the most frequent infectious cause. Viruses like coxsackievirus, echovirus, influenza, and human immunodeficiency virus (HIV) can trigger an immune response, causing inflammation and fluid production.
Bacterial infections, though less common, can also cause pericardial effusion. Bacteria can directly infect the pericardium, sometimes leading to pus formation (purulent pericarditis). Tuberculosis is a cause, as are bacteria that commonly cause pneumonia. Fungal and parasitic infections are rare causes.
Systemic Conditions and Disease-Related Causes
Broader health issues and systemic diseases can significantly contribute to the development of pericardial effusion. These conditions impact the body’s overall functioning and can indirectly affect the pericardium.
Autoimmune diseases, where the immune system mistakenly attacks the body’s own tissues, are a notable category. Conditions such as systemic lupus erythematosus (lupus), rheumatoid arthritis, and scleroderma can cause inflammation throughout the body, including the pericardium, leading to fluid accumulation. This misguided immune response can directly irritate the heart’s protective sac.
Severe kidney disease, specifically uremia, is another systemic cause. When the kidneys fail to adequately filter waste products from the blood, these substances can build up and irritate the pericardium, prompting fluid production. Similarly, an underactive thyroid gland, or hypothyroidism, can disrupt the body’s metabolism and fluid balance, sometimes resulting in pericardial effusion.
Cancer can lead to fluid around the heart through several mechanisms. Malignant cells can spread directly to the pericardium from distant tumors, with lung and breast cancer, lymphoma, and leukemia being common primary sources. In rare instances, cancer can originate in the pericardium itself, such as mesothelioma. Additionally, certain cancer treatments, like radiation therapy to the chest, can induce inflammation and effusion in the pericardium as a side effect.
Trauma, Medical Procedures, and Other Factors
Physical injuries, medical interventions, and certain other factors can also lead to pericardial effusion. These causes often involve direct impact or a reactive process within the body.
Direct chest trauma, resulting from incidents such as accidents or penetrating injuries like stab wounds, can damage the pericardium. This damage can lead to bleeding into the pericardial sac, causing fluid buildup. Even seemingly minor blunt chest trauma can sometimes result in significant effusions or delayed bleeding.
Fluid can also accumulate after heart surgery, a condition known as post-pericardiotomy syndrome. This involves an inflammatory reaction of the pericardium, occurring typically one to six weeks after the surgical procedure. Another related cause is Dressler’s syndrome, an inflammatory reaction that can develop weeks or even months after a heart attack. This syndrome is believed to result from an autoimmune response to injured heart tissue.
Certain medications can have pericardial inflammation or fluid retention as a side effect. Examples include drugs like hydralazine, procainamide, minoxidil, and some chemotherapy agents such as dasatinib. A tear in the aorta, known as an aortic dissection, can also cause bleeding into the pericardial sac, leading to a hemorrhagic pericardial effusion.
When the Cause Remains Unknown
In some instances, despite thorough medical investigation, a specific cause for fluid accumulation around the heart cannot be identified. When this occurs, the condition is referred to as idiopathic pericardial effusion. These cases are often mild and may resolve spontaneously without specific intervention.