Discrepancies in aortic growth explain aortic arch gradients during exercise

Abstract

Exercise testing detects hypertension and arch gradients in patients with a good coarctation repair as assessed at rest. The hypertension and arch "obstruction" appear to be related to discrepancies in the growth of the transverse aortic arch proximal to the repair site, rather than a "recoarctation" of the aorta.

Exercise capacity in young adults with hypertension and systolic blood pressure difference between right arm and leg after repair of coarctation of the aorta

“…This is probably because the blood pressure difference is influenced by factors such as altered arterial reactivity and baroreceptor function in the pre-coarctation vascular bed, which lead to increased blood pressure variability (Gardiner et al 1994;Guenthard and Wyler 1995). Some studies have also reported an increased arterial stiffness in the pre-coarctation vascular bed (Gardiner et al 1994;Ong et al 1992), aortic arch gradient due to discrepancies in growth of the transverse aortic arch (Weber et al 1993), hypoplasia of the distal aortic arch (Bharati and Lev 1986) and a hyperdynamic left ventricle (Ong et al 1992;Leandro et al 1992). Increased levels of catecholamines in the blood and changes in the renin-angiotensin system (Alpert et al 1979;Parker et al 1980Parker et al , 1982, and enhanced sympathetic nerve activity have been reported.…”

Impact of transverse aortic arch hypoplasia after surgical repair of aortic coarctation: An exercise echo and magnetic resonance imaging study

“…Several authors recommended exercise testing in the post-operative assessment of patients after repair of AoC for the detection of residual aortic gradients [19][20][21]. In contrast, others did not find a significant residual aortic arch gradient that could explain the post-operative exercise-induced hypertension.…”

“…The basis for a persistent hypoplasia of the TAA is unknown. End-to-end anastomosis does not enlarge the small horizontal aorta proximal to the AoC, but also discrepancies in the growth of the aortic arch proximal to the repair site have been suggested [19].…”

Pre- and Postoperative Exercise Testing of the Child with Coarctation of the Aorta

“…Weber and associates [43], utilizing maximal treadmill tests and isoproterenol infusion during cardiac catheterization, demonstrated aortic arch gradients in postop CoA patients who had no significant gradients or narrowing at the site of repair. They concluded that in some cases, discrepancies in growth of the transverse aortic arch (proximal to the coarct repair) may cause arch gradients and hypertension with exercise.…”