Cardiac tamponade can be a life threatening cause of chest pain. Diagnosis has been classically described with Beck's triad of hypotension, jugular venous distension and muffled heart tones. Penetrating trauma to the chest is the typical mechanism of developing tamponade. Untreated, it can lead to obstructive shock, impaired forward flow, and cardiopulmonary arrest. This dreaded condition can also occur outside of the setting of trauma.Case Report
A 25 year old male with a recent diagnosis of systemic lupus erythematosus (SLE) presented to the emergency department for a chief complaint of chest pain for 2 days. The patient has associated exertional shortness of breath but denied any trauma, fevers, or coagulopathy. His exam was notable for muffled heart sounds, JVD. The patient's vital signs were as follows… and a borderline systolic blood pressure of 116/58 mm Hg, heart rate of 122, respiratory rate of 18, and oxygen saturation of 100% on room air.
His chest x-ray was notable for an enlarged cardiac silhouette (Figures 1). Beside ultrasound revealed a large pericardial effusion with beat to beat compression of the right ventricle. This beat to beat compression of the right ventricle is known as the trampoline sign (Figures 2). After discussion with the General Surgeon, it was determined that since the patient was protecting his airway, not hypotensive and displayed no altered mental status, he did not require emergent pericardicentensis. The patient received 2 Liters of IV fluid in the emergency department and was transferred to local Japanese hospital for pericardiocentesis. The patient had 2 Liters of blood drained from his heart over the next 24 hours and was medivaced back to the United States for definite care. Additional ancillary studies to include pericardial fluid analysis were not made available from host nation facilities.
Pericardial effusion can be seen in a variety of condition both in and out of the trauma setting. Infection, inflammation, and autoimmune disease can be predisoping factors in non-traumatic cardiac effusions. Cardiac tamponade is a complication of large pericardial effusions and is classically seen with Beck's triad of hypotension, jugular venous distension, and muffled heart sounds. Cardiac tamponade is traditionally seen in penetrating chest trauma. However, there are cases where non traumatic pericardial effusions can progress into cardiac tamponade as seen our patient. Since the right ventricle is a low pressure system, increased transmural pressure from a large pericardial effusion can cause collapse of the right ventricle during diastole. The external force surrounding the right ventricle causes impaired filling and decreased forward flow resulting in hypotension. A reflexive tachycardia develops in order to maintain cardiac output.
In addition to Beck's triad, additional ancillary studies can be used to further this diagnosis. EKG's may show low voltage and electrical alternans. Chest X-rays may show cardiomegaly. Ultrasound has been used since the 1960's in aiding the diagnosis of pericardial effusions . The beat to beat collapse of the right ventricle is known as the trampoline sign on ultrasound. This finding was present with our patient. Left untreated, tamponade can result in low output cardiac failure and cardiopulmonary arrest. For hemodynamically stable patients without evidence of end organ ischemia, hypotension, altered mental status or other signs of end organ ischemia, the initial treatment of choice are IV fluids. IV fluids help to expand the right ventricle against the external force of a blood filled pericardium. Pericardiocentesis can also be performed in stable patients in order to drain blood or fluid from the pericardium. For patients who develop witnessed loss of vital signs and cardiopulmonary failure, emergency resuscitative thoracotomy is indicated . It is important to remember that cardiac tamponade can occur in settings outside of trauma as seen in our patient. Pericardial effusion is common cause of chest pain and the most common ultrasound finding in patients with SLE . However, cardiac tamponade is a rare complication of SLE. In a retrospective review from 1985-2006 of 71 patients with SLE who were admitted from pericarditis and pericardial effusions, only 9 (21.9%) developed cardiac tamponade and all of these were women .
Traditionally thought of as a diagnosis seen in trauma, cardiac tamponade can occur in young patients with underlying autoimmune disease. It is important for military emergency medicine physicians to recognize that there are patients who are Active Duty and who have autoimmune disease. In addition to this, patients with SLE can develop large cardiac effusions resulting in the rare complication of cardiac tamponade.