Ultrasound Case of the Month

Posted by Joelle

HPI: Two year old male with developmental delay was referred by his PCP to evaluate cardiomegaly on CXR. The patient presented to the pediatrician with 4 days of cough and fever and crackles on exam.  The CXR is shown below:

On arrival his vital signs were as follows:

•       Temperature Axillary        36.5 DegC 

•       Peripheral Pulse Rate      140 bpm  

•       Respiratory Rate              30 br/min 

•       Blood Pressure                103/71 mmHg 

•       SpO2                                 96 % 

His exam was significant for a fussy, but non-toxic appearing child with good peripheral perfusion. He was tachypneic with crackles at the lung bases and intermittent wheezes. He had no organomegaly.

Bedside US:

Diagnosis: Pericarditis with a large pericardial effusion showing tamponade physiology

Discussion:

Viral pericarditis is the second most common cause of pericarditis in children. The most commonly associated viruses are enteroviruses, especially Coxsackie B virus. Most patients presents with a prodrome of fevers and respiratory symptoms 1-2 weeks prior to development of pericarditis. They can then become acutely ill since they are more prone to have large or rapidly accumulating pericardial fluid.  (Demmler, 2006)

The ultrasound findings in this case demonstrate pericardial effusion with tamponade. Echocardiographic features of cardiac tamponade are listed in the following table:  (Fowler, 1993)

Echocardiographic Doppler Features of Cardiac Tamponade

1. Abnormal respiratory changes in ventricular dimensions

2. Right atrial compression

3. Right ventricular diastolic collapse

4. Abnormal respiratory variation in tricuspid and mitral flow velocities

5. Dilated inferior vena cava with lack of inspiratory collapse

6. Left atrial compression

7. Left ventricular diastolic compression

8. Swinging heart  

Follow up:

The patient was admitted to the Cardiology Intensive Care Unit where he had 500ml of pericardial fluid removed and a pericardial drain placed.   He was found to be Parainfluenza positive on his respiratory viral PCR panel which is thought to be the etiology of his symptoms.

References

Demmler, G. J. (2006). Infectious Pericarditis in Children. The Pediatric Infectious Disease Journal, 25(2), 165-166.

Fowler, N. (1993). Cardiac Tamponade: A Clinical or an Echocardiographic Diagnosis? Circulation, 87, 1738-1741.