A collaboration between scientists and surgeons at Bristol University and the Bristol Royal Hospital for Children have revealed that a common congenital birth defect affecting the heart and blood pressure, which can be corrected by surgery, dramatically increases the risk of cardiovascular disease in later life due to changes within the nervous system.

One of the most common heart birth defects in babies is a severe constriction of the major artery from the heart, called the aorta.  This condition is known as coarctation of the aorta.  This puts enormous strain on the heart and causes high blood pressure. 

It had been assumed that by performing corrective surgery shortly after birth, to release the constriction, all symptoms of cardiovascular disease are cured.  However, this is now known not to be the case.  Patients with repaired coarctation are five to six times more likely to develop high blood pressure in later life, putting them at increased risk of stroke, kidney failure and heart disease. 

The reason why these patients develop high blood pressure was unclear.  However, a study led by Professor Andrew Wolf at Bristol University, published this week in Circulation, has discovered that infants with coarctation of the aorta prior to corrective surgery already have changes in the nervous control of their hearts and blood vessels.  These changes are similar to those found in adults with high blood pressure.

Normally healthy babies display fluctuations in heart rate with breathing but in infants with coarctation this was reduced or absent.  This symptom is a prognostic indicator of cardiovascular disease in adults. The infant patients also exhibited very poor control of their blood pressure, which is regulated by the brain.  Again, such harmful alterations are known to contribute to high blood pressure.

Andrew Wolf, visiting Professor at Bristol University, said: “What causes these changes in the nervous system in babies with coarctation remains unknown.  However, our study will hopefully redirect medical treatment towards considering the nervous system and its influence on blood pressure and heart rate.  By taking into account interventions to the nervous system, a true cure for this disease may finally be found.”