203 NORMOTENSIVE RESPONSE TO MULTISTAGE TREADMILL EXERCISE IN POSTOP COARCTATION PATIENTS

Persistent systolic hypertension and differential gradient after successful coarctectomy have been noted during stress exercise. We evaluated 9 patients 8 to 17 years of age with a modified multistage Balke treadmill protocol. Each patient was normatensive at rest without evidence of persistent gradient, and was clinically asymptomatic 6 months to 9 years post resection or patch angioplasty. The patients were stressed to physical exhaustion at a speed of 3-3.4 mph with a grade increase of 2.5° every two minutes. The patients were observed ten minutes during recovery. Heart rate, blood pressure and 12 lead ECG were recorded at rest and every two minutes during exercise and recovery. Simultaneous blood pressure recordings of left leg and right arm were obtained at rest and at two to four minutes into recovery phase. Duration of exercise was 12-20 minutes. Maximal heart rate was 80-95% of predicted. Systolic pressure increased 35-65 mm in the right arm and when simultaneous pressures were recorded during recovery at two to four minutes, the systolic leg pressure was 10-20 mm higher. No arrhythmias or significant ST or T wave changes were noted during exercise or recovery. In summary, a group of post coarctation patients who are normatensive, fall to demonstrate a blood pressure gradient and have insignificant associated defects, had a normal response to stress exercise.