Snapshot A 45-year-old woman presents to the emergency room for chest discomfort and shortness of breath for the past few hours. She has a past medical history of systemic lupus erythematosus. Physical exam reveals hypotension, muffled heart sounds, distended jugular veins, and positive pulsus paradoxus. An ECG reveals low voltages and electrical alternans. Imaging shows an enlarged cardiac silhouette on radiography. Summary Cardiac Tamponade is a rare condition caused by the accumulation of fluid or blood in the pericardial sac that leads to compression of the heart. The condition typically presents in adults and presents with Beck's triad and pulsus paradoxus. Diagnosis is made clinically with primary symptoms such as chest pain, shortness of breath, and low blood pressure and exam findings including muffled heart sounds and jugular venous distention. Treatment is usually immediate supportive measures including IV fluids, oxygen therapy, and blood pressure stabilizing agents. However, definitive treatment is pericardiocentesis. Operative treatment of pericardiotomy is indicated in refractory pericardial effusion, constrictive pericarditis, and purulent pericarditis. Epidemiology Incidence idiopathic pericarditis 14% of patients may develop cardiac tamponade neoplastic, tuberculous, or purulent pericarditis 61% of patients may develop cardiac tamponade acute myocardial infarction treated with fibrinolytic therapy <1% risk type A aortic dissection 19% of patients may develop cardiac tamponade pericarditis associated with COVID-19 Pericardial effusions observed in 76% of cases Cardiac tamponade reported in 35% of cases Location pericardial cavity between parietal and visceral pericardium Risk factors pericarditis malignancy uremia systemic lupus erythematosus malignancy tuberculosis penetrating trauma commonly stab wounds to left nipple Etiology Pathogenesis cardiac tamponade increased pericardial pressure from the fluid accumulation causes compression of the cardiac chambers login to view 2 more bullets pulsus paradoxus normally, inhalation increases venous return → expands the right ventricle login to view 3 more bullets Pathoanatomy pericardium the pericardium is an elastic sac that can stretch to accommodate normal cardiac volume expansion login to view 1 more bullet Pericardial effusion Hemorrhage into the pericardial sac Iatrogenic Anatomy Pericardium is the membrane that encloses the heart consists of two layers fibrous pericardium is the outer layer serous pericardium is the inner layer login to view 6 more bullets Presentation Symptoms chest pain fatiguability often unresponsive to fluid resuscitation shortness of breath Physical exam key findings Beck's triad login to view 3 more bullets pulsus paradoxus login to view 1 more bullet vitals login to view 2 more bullets inspection cardiac login to view 3 more bullets auscultation cardiac login to view 1 more bullet pulmonary login to view 1 more bullet Imaging Radiography chest x-ray indication login to view 1 more bullet findings login to view 2 more bullets Transthoracic echocardiography (TTE) indications for diagnosis of cardiac tamponade test with high sensitivity and specificity for all patients urgent echocardiography may be the initial test for unstable patients with a high suspicion of cardiac tamponade findings shows right atrial and right ventricular diastolic collapse visualizes echo-free zone around the heart fluid in the pericardial space swinging of the heart within the effusion Computed Tomography (CT) indications not necessary if echocardiography is available may be used when login to view 2 more bullets findings pericardial effusion, usually large, with distention of the superior and inferior venae cavae reflux of contrast material into the azygos vein and inferior vena cava deformity and compression of the cardiac chambers and bowing of the interventricular septum Cardiovascular Magnetic Resonance (CMR) indications helps differentiate between transudative and exudative effusions login to view 1 more bullet obtain detailed anatomical information about pericardial space in complex patients to guide pericardiocentesis or pericardial surgery can detect underlying causes of cardiac tamponade such as pericardial masses, tumors, or other structural abnormalities evaluate cardiac function findings compression of cardiac chambers decreased cardiac output and elevated intracardiac pressures visualize size and location of pericardial effusion Studies Electrocardiogram (ECG) indications for all patients findings low voltage electrical alternans login to view 2 more bullets Labs CBC, CRP, ESR indications login to view 1 more bullet findings login to view 1 more bullet cardiac enzymes indications login to view 1 more bullet findings login to view 1 more bullet blood cultures indictions login to view 1 more bullet findings login to view 1 more bullet Right heart catheterization indications confirmatory test findings equilibration of pressures in all 4 chambers during diastole Diagnosis Is based on combination of clinical presentation, ECG, echocardiogram, and chest radiography Differential Constrictive pericarditis distinguishing factors found with constrictive pericarditis and not with cardiac tamponade include pulsus paradoxus, but also presents with login to view 3 more bullets Echocardiography can distinguish subacute cardiac tamponade from constrictive pericarditis, congestive heart failure, and advanced liver disease with cirrhosis Tension pneumothorax distinguishing factors found with tension pneumothorax and not found with cardiac tamponade include decreased or absent breath sounds hyperresonant percussion Pericardial effusion presents similar to cardiac tamponade with STABLE vitals Treatment Goals all approaches focus on removal of the fluid in the pericardium Medical aggressive volume expansion with IV fluids indications login to view 4 more bullets urgent pericardiocentesis indications login to view 2 more bullets findings login to view 2 more bullets Operative surgical drainage indications login to view 3 more bullets surgical drainage with pericardial window placement indications login to view 3 more bullets Techniques Pericardiocentesis approach typically performed by interventional radiologists with local anesthesia and image guidance through fluoroscopy technique image-guided needle insertion into the pericardial space and removal of fluid less invasive and can be performed more rapidly than surgical drainage complications may worsen right ventricular function or increase bleeding risk bleeding infection arrhythmia reaccumulation of fluid Surgical drainage approach done by cardiothoracic surgery under general anesthesia technique incise the pericardium and allow for evacuation of contents allows for diagnostic biopsies and pericardiectomy bioposy the sample complications clot formation in chest tubes infection excess bleeding Complications Death Prognosis In acute cases, cardiac tamponade can develop rapidly In chronic cases, cardiac tamponade will develop gradually, as the pericardium can adjust slowly to the increased pressure over time