Syncope, Seizure May Precede Cardiac Arrest in Children, Young Adults

SEATTLE – Syncope and seizures went unrecognized as warning signs of impending sudden cardiac arrest in children and young adults, based on the results of a retrospective survey of 20 families whose children had these antecedent events.

Parental reports showed that the children fainted or had a seizure without apparent reason an average of three times before sudden cardiac arrest (SCA), according to survey results presented at the annual meeting of the North American Primary Care Research Group.

Half of them did not receive an electrocardiogram (ECG) as part of their medical evaluation for these events, either because they did not see a provider or because they saw a provider but the test was not done. Yet, some of this group had cardiac pathologies that might have been detected by the test.

"Syncope and unexplained seizure activity remain unrecognized for the most part as potential warning signs of intrinsic cardiac disorders that may lead to sudden cardiac arrest," said presenting investigator Dr. Jonathan A. Drezner, a family physician specializing in sports medicine at the University of Washington, Seattle, and team physician for the Seattle Seahawks and University of Washington Huskies.

"I strongly believe that all cases of apparently benign syncope or unexplained seizure activity deserve at minimum an ECG and probably more cardiovascular workup," he recommended.

Dr. Drezner also called for better physician education to promote cardiac evaluation in this population. In particular, "ECG is not a standard part of the workup for syncope, and it needs to be," he asserted. "That message is so simple and can be so clear. But that message is not getting out."

In an earlier study, he and his colleagues retrospectively surveyed 78 families from Parent Heart Watch, a national organization of families having children who experienced (and usually died from) SCA, about a range of antecedent symptoms.

In a finding that Dr. Drezner described as alarming, 18% of these children had at least one syncopal event and 13% had at least one unexplained seizure before their SCA.

He acknowledged that there may have been some overreporting. But "these are not things that are, probably at least not as much, affected by bias from the survey and patient population – these are actually objective events that represent true warning signs of cardiovascular disease."

To assess the medical evaluation of this subset of children, the investigators sent a follow-up survey and requested telephone interviews with their 24 families.

In all, 20 families responded: 12 whose children had syncope and 8 whose children had seizures before SCA. On average, the children were about 12 years old when these symptoms began (range, 4-20 years). Age at SCA ranged from 5 to 29 years.

A striking finding, according to Dr. Drezner, was that the children had a mean of three syncopal or seizure events, with some having as many as 10 events.

This "was not a single event – these were multiple events," he commented. "These children in some way were sort of telling you something was wrong ... and perhaps maybe not identified" with multiple events, he said.

Of the 12 children who had syncope, 7 were evaluated only by their primary care provider, 1 was evaluated only by a cardiologist, 2 were evaluated by both, and 2 were evaluated by neither.

Six of these children did not receive an ECG: four who saw only their primary care provider and did not have the test, and two who saw neither provider.

"If you look at the ultimate cause of death in these individuals, these are actually detectable –and perhaps preventable – [causes of] sudden deaths that could have been detected by an electrocardiogram," Dr. Drezner pointed out.

Final diagnoses in these children and young adults who did not get an ECG were long QT syndrome, arrhythmia, myocarditis, intramural coronary artery, and autopsy-negative sudden unexplained death.

Of the eight children who had unexplained seizures, three were evaluated only by a neurologist, one was evaluated only by a cardiologist, two were evaluated by both, and two were evaluated by neither.

Five of these children received an electroencephalogram and had normal results; all of these children were nonetheless given a pre-SCA diagnosis of nonepileptic seizure. Only a single child in this group saw a cardiologist.

Overall, four of the children with seizures did not have an ECG: three who saw only a neurologist and had a normal electroencephalogram, and one who did not see either specialist. Final diagnoses in this group were long QT syndrome, arrhythmia, anomalous coronary artery, and intramural coronary artery.