Case

A 26-year-old male presented to the ED complaining of 3 days of substernal sharp chest pain that radiated to the neck and shoulder. The pain worsened with respiration and movement and improved with sitting up. Patient denied cough, fever, history of prior similar episodes of pain. Patient denied any past medical history and was taking no medications.

On exam he was afebrile with stable vital signs. HEENT exam were unremarkable. Cardiac exam revealed regular rate and rhythm with no murmur or friction rub, breath sounds were clear bilaterally. Abdomen was soft, and extremities were without edema. Patient did appear uncomfortable. EKG showed diffuse ST elevation in all leads suggestive of pericarditis.

As part of the physical exam, Limited ED Echo was performed. With the patient in the supine position, the macroconvex transducer was placed in the subxyphoid position directed at the left shoulder. A pericardial effusion was quickly detected anteriorly and posteriorly as an anechoic ring of fluid separating the visceral and parietal pericardium. (Subxyphoid Video).

• View Subxyphoid Video

The probe was the placed in the longitudinal plane in the subxyphoid position (Subxyphoid Long Video).

• View Subxyphoid Long Video

Fluid was again noted in the pericardial space. Additionally, the IVC did not collapse with inspiration consistent with increased cardiac preload (Subxyphoid Long with IVC Video).

• View Subxyphoid Long with IVC Video

Discussion

Cardiac tamponade classically although infrequently presents with Beck’s triad of muffled heart sounds, jugular venous distention, and hypotension. Incidence of tamponade in the United States is 2 per 10,000 population (1). Pericarditis presents as sharp retrosternal chest pain that radiates to the back, exacerbated by movement, relieved by sitting up, associated with cough, low-grade fevers, and dyspnea. Tamponade secondary to pericarditis is usually subacute. Patients will often become anxious, more dyspneic, and occasionally develop altered mental status. The classic triad develops only near cardiac arrest.

Limited ED Echo findings in cases of cardiac tamponade include pericardial effusion leading to swinging of heart and right ventricular collapse during diastole. Best views of right ventricular outflow tract are obtained by either the subxiphoid approach or the parasternal long axis view. Additionally, a distended IVC with lack of inspiratory collapse is frequently noted as blood prevented from entering the right heart backs up in the IVC.

The rapid addition of even small amounts of fluid to the noncompliant pericardial sac may result in impaired hemodynamic function. Acute accumulations of as little as 50ml of fluid can cause tamponade in the hypovolumic trauma patient. Slow accumulation of larger amounts of fluid in patients with renal failure or underlying malignancy results typically cause tamponade only after greater than 200ml (2). Grading of pericardial effusions remains controversial. Small effusions have a posterior hypoechogenic space < 10mm, moderate 10 –15mm and large greater than 15 mm, or an anterior and posterior space summation greater than 20mm.

Accuracy of ED physicians in making a diagnosis of pericardial effusion compared to cardiologists is 97% (3). Using Echo to aid in diagnosing tamponade is considerably more controversial. Comparisons of classic clinical diagnosis with ultrasound diagnosis have yielded a wide variation. In a study of patients with known large effusions 90% of those with clinical tamponade had ultrasound evidence of right heart collapse; however, 34% of patients without clinical signs of tamponade also had evidence of right heart collapse (3). This brings into question the specificity of right heart collapse in the diagnosis of tamponade. Here again, Limited ED Echo becomes an invaluable extension of the physical examination. Cardiac tamponade requiring emergent intervention is a clinical diagnosis; cardiovascular collapse on traditional physical examination secondary to pericardial effusion on Limited ED Echo.

Limited ED Echo not only allows for rapid diagnosis of effusion and tamponade, but also is useful for guidance of therapeutic pericardiocentesis. Emergent pericardiocentesis is a life saving procedure that can be performed at the bedside in unstable tamponade patients by using a large bore needle attached to syringe inserted just below the xiphoid and directed towards the left shoulder. Since the advent of ultrasound guided pericardiocentesis the complication rate has fallen from 50 to <1% and the mortality rate from 6 to 0% (4).

At our busy ED ACEP credentialed physicians perform limited ED Echos on patients presenting with suspected pericardial effusion, undifferentiated shock, cardiac arrest or pulmonary embolism. This rapid bedside test allows for faster diagnosis, earlier specialty consultation and disposition of critically ill patients.

Conclusion

The ultrasound was performed and a life threatening diagnosis was made quickly leading to immediate specialist intervention. The patient was taken to the operating room for a pericardial window with placement of a percutaneous drain. Four hundred milliliters of bloody fluid was drained. Work up of fluid showed non-specific picture. Cultures were all negative.

Without the use of limited ED Echo it is likely this patient would not have undergone a formal echocardiogram until the following day likely with disastrous consequences. Limited ED Echo led to life saving therapy hours if not days earlier!

References

1. Guberman BA, Fowler NO, Engel PJ, Gueron M, Allen JM. Cardiac tamponade in medical patients. Circulation 1981; 64(3):633-640.
2. Aikat S, Ghaffari S. A review of pericardial diseases: clinical, ECG and hemodynamic features and management. Cleve Clin J Med 2000; 67(12):903-914.
3. Ciccone TJ, Grossman SA. Cardiac ultrasound. Emerg Med Clin North Am 2004; 22(3):621-640.
4. Maisch B. Pericardial diseases, with a focus on etiology, pathogenesis, pathophysiology, new diagnostic imaging methods, and treatment. Curr Opin Cardiol 1994; 9(3):379-388.