Underdiagnosis of Conditions Associated with Sudden Cardiac Death in Children--Is it the Absence of a Comprehensive Screening Program or a True Low Prevalence?

This study aimed to assess the prevalence of conditions associated with sudden cardiac death (SCD) among all children and children with sudden infant death syndrome (SIDS) in the State of Hawai'i, where no comprehensive screening program is conducted for such conditions. A retrospective chart review was conducted from the single tertiary pediatric hospital in Hawai'i, from offices of all pediatric cardiologists in Hawai'i, and the Hawai'i State Department of Health from 1/1/2000 to 12/31/2013. Children aged 0-18 years were included in the study. A subset of the study analyzed records of infants aged 0-12 months. SIDS rate was calculated and compared to national data. Prevalence was calculated for known conditions associated with SCD. The identified prevalence was compared to the established prevalence of conditions associated with SCD. In Hawai'i, the infant SIDS rate (66.4/100,000) was similar to the national rate (54.4/100,000). Over 14 years, only 51 children were diagnosed with a condition associated with SCD; 28 with a cardiomyopathy and 21 with a channelopathy. A 14-year retrospective analysis in the State of Hawai'i revealed that less than 1 in 30 children, who are expected to harbor a SCD-associated condition, had been appropriately diagnosed. The underdiagnosis of conditions associated with SCD reflects that in the absence of a comprehensive screening program, conditions without obvious signs and symptoms are difficult to diagnose. Many children with these conditions will remain at risk of SCD.

Auditory temporal processes in normal-hearing individuals and in patients with auditory neuropathy.

OBJECTIVE: To study objectively auditory temporal processing in a group of normal hearing subjects and in a group of hearing-impaired individuals with auditory neuropathy (AN) using electrophysiological and psychoacoustic methods. METHODS: Scalp recorded evoked potentials were measured to brief silent intervals (gaps) varying between 2 and 50ms embedded in continuous noise. Latencies and amplitudes of N100 and P200 were measured and analyzed in two conditions: (1) active, when using a button in response to gaps; (2) passive, listening, but not responding. RESULTS: In normal subjects evoked potentials (N100/P200 components) were recorded in response to gaps as short as 5ms in both active and passive conditions. Gap evoked potentials in AN subjects appeared only with prolonged gap durations (10-50ms). There was a close association between gap detection thresholds measured psychoacoustically and electrophysiologically in both normals and in AN subjects. CONCLUSIONS: Auditory cortical potentials can provide objective measures of auditory temporal processes. SIGNIFICANCE: The combination of electrophysiological and psychoacoustic methods converged to provide useful objective measures for studying auditory cortical temporal processing in normals and hearing-impaired individuals. The procedure used may also provide objective measures of temporal processing for evaluating special populations such as children who may not be able to provide subjective responses.