Uremic pericarditis overview

# Overview
Renal failure can be associated with the development of a pericardial effusion and pericarditis, a condition known as uremic pericarditis.  The underlying pathophysiology is not entirely clear, but it is hypothesized that uremic pericarditis is due to a build up of metabolic toxins such as urea, creatinine, methylguanidine which cause inflammation of pericardium.  With the introduction of dialysis, the incidence of uremic pericarditis has dropped.

# Differentiating Uremic Pericarditis from other Diseases
Signs and symptoms of pericarditis may be similar to several other conditions including myocardial infarction, aortic dissection and pulmonary embolism which are life threatening and therefore it is important to differentiate them. Pain along the trapezius ridge, which is unresponsive to vasodilator therapy and varies with position, is a specific sign of pericarditis.

# Diagnosis

## Laboratory Findings
Non-specific markers of inflammation are generally elevated in pericarditis. These include the leukocyte count, C-reactive protein, and ESR. The cardiac troponin is elevated if there is an injury to the underlying myocardium, a condition termed as myopericarditis. Diagnostic pericardiocentesis and biopsy help in identifying an underlying infectious or malignant process.

## Echocardiography
Echocardiogram may show presence of fluid surrounding the heart in pericardial effusion. Loculated effusions secondary to adhesions in pericardial cavity may also be visualized as shown in the video below. 
Swinging motion of the heart may be seen in patients with cardiac tamponade.

## CT
On CT, pericardial fluid adds to the thickness of pericardium as both have the similar signal intensities. In pericarditis, pericardium can generate an intermediate signal intensity and may enhance after gadolinium administration. In pericardial effusion, hemorrhagic effusions can be differentiated from a transudate or an exudate based on signal characteristics (high signal on T1-weighted images) or density (high-density clot on CT). CT is superior to MRI in the visualization of pericardial calcification which is often seen in the patient with pericardial constriction. CT imaging also helps in detecting the presence of tumors and the extent of metastasis of the neoplasm.

## MRI
On MRI, normal pericardium appears as a thin dark band that is bordered by a bright band on both sides on T1 weighted spin imaging. These surrounding bright bands are associated with the surrounding epicardial and pericardial fat. Following the administration of gadolinium, pericardium may appear thick and inflamed in the setting of pericarditis. Lower intensity signal is observed in constrictive pericarditis than in acute pericarditis. Comprehensive visualization of the LV endocardium and the physiologic consequences of abnormal pericardial thickening can also be obtained without exposure to ionizing radiation.

## Cardiac Catheterization
In presence Cardiac tamponade, there is equalization of pressures in all four chambers of heart. The right atrial pressure equals the right ventricular end diastolic pressure equals the pulmonary artery diastolic pressure.