Aortic Root Dimension and Hypertension: A Chicken-Egg Dilemma

T he structural and functional characteristics of ascending aorta, receiving ejected volume at each beat, are important biological factors in the pathophysiology of arterial hypertension. Whatever cause is found in the background of hypertension, elevation of blood pressure (BP) occurs when the amount of blood pushed into the arterial tree is not offset by a corresponding reduction of the impedance load opposed to the outflow, as the interplay between elastic conduits and high resistance terminal arteries. Whereas a logical sequence of pathophysiologic alterations would consider high BP as one of determinants of enlarged aortic root dimension, most studies could not identify a close enough association to hypothesize a cause–effect relationship.1 One potential reason of the inconsistency between assumption and reality could lay on the different pathophysiology sustaining systolic and diastolic hypertension, as well as on the cross-sectional nature of the studies. In this issue of the journal, Farasat et al.2 examine correlates of aortic root dimensions in well-defined sub-types of arterial hypertension, including normality (N), prehypertension (PH), isolated systolic (ISH), isolated diastolic (IDH), and combined systo-diastolic hypertension (SDH). This study proposes results that help understanding some method limitations, favor a better comprehension of the interplay between conductance arteries and hypertension, and eventually might track research in this field.