Amplitude-integrated EEG in newborns with critical congenital heart disease predicts preoperative brain magnetic resonance imaging findings

Abstract

Objective: The study aims are to evaluate cerebral background patterns using amplitude-integrated electroencephalography in newborns with critical congenital heart disease, determine if amplitude-integrated electroencephalography is predictive of preoperative brain injury, and assess the incidence of preoperative seizures. We hypothesize that amplitude-integrated electroencephalography will show abnormal background patterns in the early preoperative period in infants with congenital heart disease that have preoperative brain injury on magnetic resonance imaging.

Methods: Twenty-four newborns with congenital heart disease requiring surgery at younger than 30 days of age were prospectively enrolled within the first 3 days of age at a tertiary care pediatric hospital. Infants had amplitude-integrated electroencephalography for 24 hours beginning close to birth and preoperative brain magnetic resonance imaging. The amplitude-integrated electroencephalographies were read to determine if the background pattern was normal, mildly abnormal, or severely abnormal. The presence of seizures and sleep-wake cycling were noted. The preoperative brain magnetic resonance imaging scans were used for brain injury and brain atrophy assessment.

Results: Fifteen of 24 infants had abnormal amplitude-integrated electroencephalography at 0.71 (0-2) (mean [range]) days of age. In five infants, the background pattern was severely abnormal. (burst suppression and/or continuous low voltage). Of the 15 infants with abnormal amplitude-integrated electroencephalography, 9 (60%) had brain injury. One infant with brain injury had a seizure on amplitude-integrated electroencephalography. A severely abnormal background pattern on amplitude-integrated electroencephalography was associated with brain atrophy (P = 0.03) and absent sleep-wake cycling (P = 0.022).

Conclusion: Background cerebral activity is abnormal on amplitude-integrated electroencephalography following birth in newborns with congenital heart disease who have findings of brain injury and/or brain atrophy on preoperative brain magnetic resonance imaging.

Keywords: brain injury; congenital heart disease; electroencephalography; neuromonitoring; newborn; seizures.

Fig. 1. Sample aEEG and Corresponding Raw EEG in Newborns with CHD

A: A normal aEEG showing continuous normal voltage and sleep-wake cycling in a 0 day old 39 week gestation newborn with hypoplastic left heart syndrome (Infant 2, Table 2). B: A mildly abnormal aEEG showing a discontinuous normal voltage pattern in a 1 day old 37 week gestation newborn with heterotaxy syndrome, double outlet right ventricle, and pulmonary stenosis (Infant 14, Table 2). C: A severely abnormal aEEG background pattern showing burst suppression in a 2 day old 37 week gestation newborn with hypoplastic left heart syndrome (Infant 20, Table 2).

Fig. 2. Background aEEG pattern in 24 CHD newborns

An aEEG was considered normal when the background pattern was continuous normal voltage for the entire recording. Mildly abnormal was considered when the tracing showed discontinuous normal voltage during the recording and a severely abnormal background pattern was documented when the tracing showed burst suppression, continuous low voltage, or flat trace.