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

Abstract

Coarctation of the aorta represents 5-7% of congenital heart defects. Symptoms and prognosis depend on the degree of stenosis, age at surgery, surgical method and the presence of other heart defects. Postoperative complications are hypertension, restenosis and an abnormal blood pressure response during exercise. This study includes 41 patients, 15-40 years old, operated in the period 1975-1996. All were exercised on a treadmill until maximal oxygen consumption was achieved. Blood pressure was measured in the right arm and leg before and immediately after exercise, and in the right arm during exercise. Oxygen consumption was monitored and we defined an aerobic phase, an isocapnic buffering phase and a hypocapnic hyperventilation phase. The resting systolic blood pressure correlates with the resting systolic blood pressure difference between right arm and leg. A resting systolic blood pressure difference between the right arm and leg of 0.13 kPa (1 mmHg) to 2.67 kPa (20 mmHg) corresponds with a slight increase in resting systolic blood pressure. This rise in blood pressure increases the aerobic phase of the exercise test, helping the patients to achieve higher maximal oxygen consumption. A resting systolic blood pressure difference of more than 2.67 kPa (20 mmHg) corresponds with severe hypertension and causes reduction in the aerobic phase and maximal oxygen consumption. Resting systolic blood pressure and resting systolic blood pressure difference between the right arm and leg are not indicators for blood pressure response during exercise. Exercise testing is important to reveal exercise-induced hypertension and to monitor changes in transition from aerobic to anaerobic exercise and limitation to exercise capacity.

Ventricular–Vascular Stiffening in Patients With Repaired Coarctation of Aorta

“…Indeed, decreased exercise tolerance has been reported in patients with repaired COA. 27,41,42 Although hypertension was phenomenologically linked to this abnormality, the underlying mechanisms remain unclear. The present study has clearly demonstrated that high basal Ees limits ability to increase stroke volume despite greater increase in Ees during ␤-adrenergic stimulation, whereas further increases in both Ees and Ea with adrenergic stimulation augment the rise in systolic BP.…”

Exercise-induced hypertension in patients after repair of aortic coarctation

“…In this issue, Instebo et al (2004) report that resting systolic blood pressure is not an indicator of maximal exercise systolic blood pressure in 41 patients after repair of aortic coarctation. This result is in contrast with a recent study of our group.…”

“…In the study of Instebo et al (2004) mean systolic blood pressure in the right arm was 148 (11) mmHg for group 2 and 163 (16) mmHg for group 3, raising the question if any of these hypertensive patients received anti-hypertensive treatment, which could complicate analysis. The authors do not provide data on the successfulness of their coarctation repair.…”

“…The study by Instebo et al (2004) on exercise capacity and exercise blood pressure in patients after repair of aortic coarctation is a welcome reminder of the cardiovascular morbidity associated with-as was previously thought-''a simple and easily corrected lesion''.…”

The significance of the residual blood pressure drop across the site of coarctation repair

“…However, the results are not consistent, which fuels the discussion on how blood pressure is best measured, what treatment is most efficient, and how the effect is best evaluated. The letter to the Editors in the present issue, from Vriend and Mulder (2005), is an important contribution to this discussion.As part of our follow-up program of patients operated for coarctation of the aorta, their exercise capacity was studied (Instebø et al 2004). Most of these patients had dropped out of the program (Thu et al 1999).…”