Adding an ECG to a history and physical exam in healthy children and adolescents can identify potentially serious heart conditions that can increase the risk of sudden cardiac arrest (SCA), according to a study published March 15 in the American Heart Journal.
Researchers noted that SCA in children is associated with structural and electrical cardiac abnormalities. Yet, no studies have systematically screened healthy school children in the U.S. for conditions leading to SCA to identify those at risk. They wrote that while European screening recommendations include screening for children and all athletes—and with 12-lead ECG, U.S. recommendations only include screening athletes and even then, only with a history and physical exam, not a 12-lead ECG.
"In Italy and Japan, which have compulsory screening of all athletes or schoolchildren, researchers have found that adding an ECG to the history and physical increases the likelihood of detecting children at risk for SCA," said lead author Victoria L. Vetter, MD, MPH, a pediatric cardiologist at Children's Hospital of Philadelphia (CHOP).
Vetter and colleagues called for more data to evaluate the efficacy of the current U.S. screening compared to ECG and/or echocardiographic screening.
To add to the data, the researchers screened 400 healthy five- to 19-year-olds in clinical offices at CHOP between June 2006 to June 2007.
They used a medical and family history questionnaire, weight, height, blood pressure, heart rate, cardiac examination, 15-lead ECG and echocardiogram. Each exam lasted between 30 and 60 minutes.
"Our goals were to determine the feasibility of adding an ECG to history and physical examination and to identify a methodology to be used in a larger multicenter study," they wrote. A secondary objective was to compare identification of cardiovascular abnormalities by history and physical exam, ECG and echo.
"The echo served to identify false positives and false negatives for structural and functional cardiac conditions when compared to the ECG," the authors wrote.
Vetter and colleagues found undiagnosed cardiac abnormalities in 23 subjects and an additional 20 had hypertension. They identified potentially serious cardiac conditions in 10 subjects.
ECG identified two prolonged QT interval/LQTS, one Wolff-Parkinson-White anomaly, two complex ventricular ectopy, one ostium primum atrial septal defect (ASD) and one left ventricular dysfunction, with the latter two confirmed by echo. ECG had eight false positives, two true positives, and one borderline.
Echo alone identified two dilated aorta cases and one anomalous left circumflex coronary artery. Only one of the 10 subjects had symptoms (previously dismissed) and none had a positive family history.
Researchers noted that the ASD was suspected from the cardiologist's physical exam, which then was suggested by ECG and confirmed by echo.
Overall, six abnormal conditions were identified or suspected from the ECG alone, and one more was first suspected from ECG, then by physical examination, and subsequently confirmed by echo.
The exams also found previously undiagnosed less serious forms of heart disease in 13 children, including mild atrioventricular and semilunar valve regurgitation and a small patent ductus arteriosus. Overall, additional testing to clarify diagnosis was performed in 24 subjects.
Vetter and colleagues concluded from this pilot study that it is feasible to use ECG to screen school-aged children. "The echo further enhanced the identification of abnormalities, but "in our study, the ECG was over three times more likely than the history and physical examination to identify true abnormalities."
The authors added that the children in the screening were not all high school athletes, and most would not have undergone athletic cardiac screening. Regular physical exams by primary care physicians had not detected the cardiac conditions found in the current study.
"Performing the ECG and its interpretation added less than 10 minutes to each subject's total evaluation," said Vetter, adding that the ECG machines are portable and relatively inexpensive.