Discussion:
Our 10 week old female infant was a unique case as she was asymptomatic until she was 9 weeks old. It is unclear as to what specifically caused her to have cardiac arrest. We also suspect that when the baby limped and cried with sudden increase of intrathoracic pressure the cystic compoment of the mass might have ruptured to aggravate the pericardial effusion and precipitated the tamponade, resulting in cardiac arrest. It is equally possible that the large pericardial effusion found in bedside echocardiogram may have caused electric conduction disruptions in her heart leading to cardiac arrest. Review of the literature showed no case reports detailing an otherwise healthy infant presenting with cardiac arrest as a result of a cardiac mass. This case highlights the importance of close prenatal screening and to have a high suspicion for intrapericardial masses as a possible cause of cardiac arrest. Early identification allows for interventions such as pericardiocentesis, or thoraco/pericardio-amniotic shunt to be done in-utero allowing for prolongation of pregnancy2,5,8. On echocardiogram a patent foramen ovale with a small shunt was present, which may have prevented symptoms from presenting earlier.