Impaired carotid artery elastic function in patients with tetralogy of Fallot

Complex congenital heart diseases with abnormal formation of the aorticopulmonary septum are also associated with defective large artery elastogenesis. In the current study, we tested the hypothesis that carotid artery elastic function was impaired in patients with tetralogy of Fallot (ToF). The study included 45 Fallot-patients (male: female 27: 18; age 21.0 +/- 11.8 years) and 45 age-and gender-matched healthy control individuals. Carotid artery diameter, pulsatile distension, and intima-media thickness (IMT) were measured by echotracking device, and carotid blood pressure was determined using applanation tonometry. Carotid artery elasticity was characterized by compliance and distensibility coefficients, stiffness index beta, and incremental elastic modulus. All carotid artery elastic parameters showed significant differences between groups. The compliance coefficient was 36%, and the distensibility coefficient was 33% smaller, whereas stiffness index beta was 46% and incremental elastic modulus was 40% larger in Fallot-patients. Fallot-patients also had larger carotid artery IMT as compared to that of healthy individuals. Carotid artery is markedly stiffer in Fallot-patients suggesting that impaired elastogenesis is a component of the congenital abnormality. Increased large artery stiffness might contribute directly and indirectly (through impairment of baroreflex function) to the higher mortality found in ToF patients.