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 echocardiogram (ECG) reveals low voltages and electrical alternans. Imaging shows an enlarged cardiac silhouette on radiography. A team is consulted for an emergent pericardiocentesis. 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 results in reduced ventricular filling and decreased cardiac output rate of fluid formation is more important than size of effusion pulsus paradoxus normally, inhalation increases venous return → expands the right ventricle in cardiac tamponade, the stiff pericardium will prevent the free wall from expanding the only area for the right ventricle to expand is the interventricular septum, which will compress the left ventricle compression of the left ventricle → decreased filling of the left heart → decreased blood pressure Pathoanatomy pericardium the pericardium is an elastic sac that can stretch to accommodate normal cardiac volume expansion however, if stretched beyond normal physiological expansion, the pericardium will stiffen 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 also divided into two layers parietal pericardium visceral pericardium (epicardium) pericardial cavity space between the parietal and visceral pericardium fills with 15-50 mL of serous fluid Presentation Symptoms chest pain fatiguability often unresponsive to fluid resuscitation shortness of breath Physical exam key findings Beck's triad muffled heart sounds jugular venous distention hypotension pulsus paradoxus a decrease in blood pressure > 10 mmHg during inhalation vitals ↑ heart rate narrow pulse pressure inspection cardiac extremities cold and clammy peripheral cyanosis auscultation cardiac pericardial rub if the patient has an inflammatory pericarditis pulmonary lung fields are typically clear Imaging Radiography chest x-ray indication for all patients findings enlarged cardiac silhouette seen only in subacute cardiac tamponade in acute cases, pericardium will not accommodate build up of > 200 cc of fluid, which is required to appear enlarged on radiography 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 subacute or regional tamponade is suspected evaluating complex effusions 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 detailed information on volume and distribution of fluid 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 variations in the height of the QRS complex from swinging of the heart in the chest Labs CBC, CRP, ESR indications evaluate for signs of infection or inflammation findings elevated in cases of infection or pericarditis cardiac enzymes indications to assess for myocardial damage findings elevated in cases of myocardial infarction blood cultures indictions suspicion of infectious pericarditis leading to tamponade findings determination of causative organism 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 Kussmaul sign increase (or absence of decline) in jugular venous pressure with inhalation pericardial knock 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 cardiac tamponade without hemodynamic compromise modalities serial echocardiographs intravenous bolus of fluids urgent pericardiocentesis indications first-line of treatment in most patients should be avoided in patients with severe pulmonary hypertension or bleeding diathesis/coagulopathy findings nonclotting blood is seen in aspirate etiology of fluid can be determined in lab Operative surgical drainage indications patients with coagulopathy or need for biopsy purulent pericarditis traumatic cardiac tamponade surgical drainage with pericardial window placement indications significant drainage continues for more than 3 to 4 days patients with recurrent pericardial effusions patients who decompensate 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