Reduced heart rate variability (HRV), anindicator of autonomic nervous systemdysfunction, can be used to identify critically ill patients at higher risk for adverse outcomes.Limited data exists on HRV in children withcardiac disease. Early detection of reduced HRV with home monitoring systems may lead to improved outcomes in high-risk infants withcomplex congenital heart disease. Home ECG monitoring is a valid method to obtain HRV data.