Summer, Strep May Affect Baby's Heart
Hypoplastic Left Heart Syndrome (HLHS), a congenital heart disease that often leads to death in newborns, is significantly more common during the summer, leading researchers to believe that the environment may play a role in causing the disease.
Pirooz Eghtesady, MD, PhD, a cardiothoracic surgeon at Cincinnati Children’s Hospital Medical Center, led a study of nearly 1,500 newborns who had left-sided congenital heart diseases. The babies were from 38 children’s hospitals in the United States. Eghtesady and his colleagues found a seasonal occurrence of HLHS, but no other left-sided diseases, over a 10-year period from 1996 to 2006. Seasonal differences in HLHS occurred each year, with peaks between April and July and low points in January.
One potential environmental factor being studied by Dr. Eghtesady and colleagues is mothers’ recurrent exposure to the common agent strep throat (also responsible for rheumatic heart disease) during summer months. Numerous studies have indicated that an immune reaction against strep in rheumatic heart disease can lead to injury on the left side of the heart, which is the side affected in HLHS. Eghtesady’s preliminary study suggests that many mothers whose newborns had left-sided heart injury had a significant history of problems related to strep throat.
HLHS remains one of the most complex and challenging to manage of all congenital heart defects. In a child with HLHS, all structures on the left side of the heart are severely underdeveloped. The result is that the left side of the heart is unable to support the circulation needed by the body's organs.
Cincinnati Children’s is involved in an ongoing clinical trial looking at maternal history of strep exposure compared to mothers with normal hearts and mothers affected by other cardiac defects. Researchers at Cincinnati Children’s also are studying whether there are antibodies in the blood of mothers exposed to strep similar to ones found in patients with rheumatic heart disease.
