Cardiac Tamponade - Cardiovascular

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.
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 the 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 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 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 a decrease in 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 accommodate build up of > 200 cc of fluid, which is required to appear enlarged on radiography
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 Right heart catheterization indication typically not performed as an initial test findings 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 Pericardial effusion presents similar to cardiac tamponade with STABLE vitals
Treatment
Management approach all approaches focus on removal of the fluid in the pericardium Conservative 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