Aortic distensibility and dilation in Turners syndrome

Background: Aortic dilation and dissection is reported in patients with Turners syndrome, both with and without cardiovascular risk factors. The bicuspid aortic valve is closely associated with dilated aortic root, although expression of aortic dilation is variable. The determinants for variable expression of aortic dilation in individuals with Turners syndrome, however, are unknown. Hypothesis: A primary mesenchymal defect is prevalent in individuals with Turners syndrome, suggested by having abnormalities in bone matrix, and lymphatic and peripheral blood vessels. We hypothesize that an abnormal intrinsic elastic property of aorta is a forerunner of aortic dilation in Turners syndrome. Objective: Assess utility of aortic distensibility as a measure of aortic elasticity for the stratification of the risk for aortic dilation, and its relationship with age, karyotype, and hormonal therapy. Design: Prospective cross-sectional study. Patients and method: We performed cross-sectional M-mode and Doppler echocardiography in 24 individuals with Turners syndrome. Dimensions of the aortic root, and its distensibility, were calculated using standard techniques. We also examined a control group of 24 age matched normotensive patients with structurally normal hearts, who had been referred for evaluation of cardiac murmurs or chest pain. Results: Aortic dilation was the most common cardiac anomaly, seen in 11 of 24 (46%) individuals with Turners syndrome, and none in control group. Of these individuals, 5 without cardiovascular risk factors had aortic dilation. In 2 young girls, aortic dimensions were normal, albeit with reduced distensibility. Aortic dilation correlated inversely with aortic distensibility, but not with age, karyotype or hormonal therapy. Conclusion: Individuals with Turners syndrome, even without cardiovascular risk factors, do develop aortic dilation accompanied by decreased aortic distensibility, suggestive of an intrinsic abnormality in elastic property of the ascending aorta.