"Water can" appearance of heart shadow in a Chest X-ray is seen in

(A) Pericardial effusion # PERICARDIAL EFFUSION defines the presence of an abnormal amount and/or character of fluid in the pericardial space. It can be caused by a variety of local and systemic disorders, or it may be idiopathic.> Pericardial space normally contains 15-50 mL of fluid, which serves as lubrication for the visceral and parietal layers of the pericardium.> This fluid is thought to originate from the visceral pericardium and is essentially an ultrafiltrate of plasma. Total protein levels are generally low; however, the concentration of albumin is increased in pericardial fluids owing to its low molecular weight. Classic Beck triad of pericardial tamponade (hypotension, muffled heart sounds, jugular venous distension) Pulsus paradoxus: Exaggeration of physiologic respiratory variation in systemic blood pressure, defined as a decrease in systolic blood pressure of more than 10 mm Hg with inspiration, signaling falling cardiac output during inspiration. Pericardial friction rub:The most important physical sign of acute pericarditis may have up to 3 components per cardiac cycle and is high-pitched, scratching, and grating. Ewart sign - Dullness to percussion beneath the angle of left scapula from compression of the left lung by pericardial fluid> Chest radiography Findings include enlarged cardiac silhouette (so-called water-bottle heart or flask), pericardial fat stripe. A third of patients have a coexisting pleural effusion.> Echocardiogram This is the criterion standard for noninvasive diagnosis. Pericardial effusion appears as an "echo-free" space between the visceral and parietal pericardium