Isoproterenol stress test during catheterization of patients with coarctation of the aorta.

Background:  The exercise test is considered useful in selecting high-risk patients with repaired coarctation of the aorta (CoA), but it is difficult to obtain the cooperation of pediatric patients. The present study determines the feasibility of the isoproterenol stress test (IST) among pediatric patients with CoA. Methods:  Thirteen patients with repaired or mild preoperative CoA aged 1–207 (median 13) months underwent 16 IST during cardiac catheterization. Peak-to-peak pressure gradients (PG) over the coarctation site were measured at baseline and at IST. Balloon angioplasty (BAP) was applied to patients with significant stenosis on angiography. Results:  The PG between the ascending and the descending aorta was significantly higher at IST than at baseline (20.5 ± 11.5 vs 5.6 ± 3.9 mmHg, P 10 mmHg in three of six patients after BAP. Conclusions:  Significant pressure gradients over the coarctation site develop at IST in pediatric patients with repaired CoA or in preoperative patients with mild coarctation.