Snapshot A 19-year-old man is stabbed in the left side of his chest. His blood pressure on presentation is 90/60 mmHg with a pulse of 130/min. On physical exam, he has muffled heart sounds and distended jugular veins. Upon inspiration, his blood pressure drops to 75/55 mmHg. His extremities are cool and clammy. He is immediately rushed to the operating room. Introduction Clinical definition accumulation of fluid in the pericardial sac that restricts ventricular filling Epidemiology risk factors pericarditis malignancy uremia systemic lupus erythematosus malignancy tuberculosis penetrating trauma Etiology pericardial effusion hemorrhage into pericardial sac iatrogenic 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 Pathogenesis cardiac tamponade increased pericardial pressure from the fluid accumulation causes compression of the cardiac chambers this results in decreased cardiac output and blood pressure pulsus paradoxus 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 Associated conditions ruptured ascending aortic dissection ventricular free wall rupture from myocardial infarction 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 Presentation Symptoms chest pain fatigability often unresponsive to fluid resuscitation Physical exam Beck triad muffled heart sounds jugular venous distention hypotension cardiac ↑ heart rate pericardial rub if the patient has an inflammatory pericarditis pulsus paradoxus decrease of blood pressure > 10 mmHg during inhalation pulmonary shortness of breath lung fields are typically clear extremities cold and clammy peripheral cyanosis Imaging Echocardiography indications for diagnosis of cardiac tamponade most accurate test for all patients findings diastolic collapse of the right heart fluid in the pericardial space swinging of the heart within the effusion Radiography indication for all patients views chest findings enlarged cardiac silhouette seen only in subacute cardiac tamponade in acute cases, pericardium will not accomodate build up of > 200 cc of fluid, which is required to appear enlarged on radiograph Studies Electrocardiogram (ECG) indication for all patients findings low voltage electrical alternans variations in the height of the QRS complex from swinging of the heart in the chest Right heart catheterization indication typically not performed as an initial test finding equilibration of pressures in all 4 chambers during diastole Making the diagnosis based on clinical presentation, ECG, echocardiogram, and chest radiography Differential Constrictive pericarditis distinguishing factors also has pulsus paradoxus, but also presents with Kussmaul sign increase (or absence of decline) in jugular venous pressure with inhalation pericardial knock Tension pneumothorax distinguishing factors decreased or absent breath sounds hyperresonant percussion Treatment Management approach all approaches focus on removal of the fluid in the pericardium Nonoperative close monitoring and volume expansion indication cardiac tamponade without hemodynamic compromise modalities serial echocardiographs intravenous bolus of fluids Procedural percutaneous pericardiocentesis indication first-line treatment Operative surgical drainage indications patients with coagulopathy or need for biopsy purulent pericarditis traumatic cardiac tamponade surgical drainage with pericardial window placement indication patients with chronic pericardial effusions patients who decompensate Complications Death