Studies examine issues in pediatric cardiology

“This study shows, for the first time, that the newborn human ventricle, in addition to having reduced response to stimulation with isoproterenol or forskolin, also has a diminished ability to respond positively to increased heart rate, when compared to infants three to 12 months old,” said Carlo M. Zeidenweber, M.D., of Emory University, Children’s Healthcare of Atlanta Sibley Heart Center and lead investigator on this study. “This suggests that it may be difficult to improve contractility at birth, but that our ability to intervene increases over the first year of life. Further studies in this patient population will seek to determine the specific causes for differences in the newborn heart, including the possibility of altered levels of specific proteins, such as NCX and PLB.”

Dr. Zeidenweber will present this study on Sunday, March 25, at 2:30 p.m. in Hall H.

Congenital Vascular Rings And Slings Are A Significantly Under-diagnosed Cause Of Childhood Diseases: Screening Of 186,213 School-aged Children By Echocardiography (Presentation Number: 1005-32)

Vascular rings are congenital anomalies that occur early in the development of the aortic arch (the part of the aorta that leaves the heart and turns downward) and great vessels (five vessels above the aortic arch). This group of anomalies has been thought to be rare and doctors most often maintain a high index of suspicion of nonspecific signs of vascular rings via changes to the structures encircled by the rings, primarily the trachea and esophagus. Such changes could include stridor (a harsh, high-pitched respiratory sound) or breathing noises, recurrent lung infections and asthma, as well as difficulty breathing and swallowing. Prompt diagnosis and treatment of these congenital abnormalities can be lifesaving.

In a collaborative study conducted by researchers at Chung Shan Medical University Hospital in Taiwan and Baylor College of Medicine and Texas Children’s Hospital in Texas, 186,213 primary and junior high school children in Taichung County were screened for signs of cardiovascular abnormalities by medical history, physical examination, electrocardiogram (ECG) and portable 2D echocardiography (2DE) from 2001 through 2004. If any significant congenital cardiovascular diseases (CCVD) were suspected or not definitive, especially congenital vascular ring and sling abnormality (CVRSA), the patient was referred to a tertiary care center for a complete evaluation, which included a standard 2DE, computed tomography (CT) scan, magnetic resonance imaging (MRI) or angiography (X-ray of blood vessels).

Of the children screened, a total of 2,319 cases with CCVD were diagnosed. There were only four complex CVD cases, of asymptomatic congenitally-corrected transposition of the great arteries (L-TGA, a combination of two heart abnormalities that cancel each other out) in this age group. Newly diagnosed CHDs were frequent, including: patent foramen ovale (hole between right and left atria, n=618); patent ductus arteriosus (blood vessel in heart which fails to close, n=213); atrial septal defect (abnormal opening between left and right atria, n=180); pulmonary stenosis (narrowing between right ventricle and lung artery, n=54); ventricular septal defect (hole between left and right ventricles, n=37); aortic stenosis (abnormal narrowing of aortic valve, n=6); and others (n=17). CVRSA was the most prevalent of the abnormalities (6 in every 1,000 children), including: