Constrictive pericarditis is a condition characterized by decreased elasticity and an increased thickening of the pericardium. These changes reduce the ability of the heart to fill with blood and can lead to symptoms of heart failure. Understanding the differing etiologies and disease processes is important as it can lead to a timely diagnosis and appropriate treatment.
Signs and symptoms
Constrictive pericarditis can present with symptoms such as difficulty breathing, fatigue, abdominal swelling, or swelling of legs. Outside of these areas the next most common cause is typically idiopathic or viral in nature.
- Incomplete drainage of purulent pericarditis
Pathophysiology
thumb|Constrictive pericarditis
The pathophysiological characteristics of constrictive pericarditis are due to a thickened, fibrotic pericardium that forms a non-compliant shell around the heart. This shell prevents the heart from expanding when blood enters it. As pressure on the heart increases, the Stroke volume decreases as a result of a reduction in the ability of the heart to fill blood during Diastole. This results in significant changes in blood flow based on the stage of respiration.
During inspiration, pressure in the thoracic cavity decreases but is not relayed to the left atrium which can lead to a reduced flow to the left atrium and ventricle. During diastole, less blood flow in the left ventricle allows for more room for filling in right ventricle and therefore a septal shift occurs.
During expiration, the amount of blood entering the left ventricle will increase, allowing the interventricular septum to bulge towards the right ventricle, decreasing the right heart ventricular filing.
- Transient (subacute) constrictive pericarditis: constrictive pathophysiology may be reversible due to a transient inflammatory state that resolves without significant fibrosis.
- Chest X-Ray - pericardial calcification (common but not specific), pleural effusions are common findings.
- Echocardiography - the principal echographic finding is changes in cardiac chamber volume.
- BNP blood test - tests for the existence of the cardiac hormone brain natriuretic peptide, which is only present in restrictive cardiomyopathy but not in constrictive pericarditis
- Conventional cardiac catheterization
thumb|X-ray demonstrating constrictive pericarditis with calcifications.
Treatment
thumb|Pericardium visualized in open heart surgery
Transient or subacute constrictive pericarditis is treated with anti-inflammatory medication and can resolve without surgical intervention in many cases. with mortality rates of 6% or higher in major referral centers.
A poor outcome is often the result after a pericardiectomy is performed for radiation-induced constrictive pericarditis, and some patients may develop heart failure post-operatively.
Epidemiology
Constrictive pericarditis is a rare complication of many pericardial diseases.