Doppler echocardiography during exercise to predict residual narrowing of the aorta after coarctation resection.
Blood pressure measurements and Doppler echocardiography at rest and during exercise were performed in 36 patients at an average 17 years after coarctation resection. Interest focused on the study of Doppler systolic and diastolic gradients and half-times during exercise. Blood pressure gradients and Doppler values were compared with the degree of narrowing at the site of the anastomosis measured by magnetic resonance imaging. A systolic half-time of >110 ms together with a diastolic gradient of >/=17 mmHg on exercise Doppler sonography predicted a residual isthmic narrowing of >30%. We propose the use of this noninvasive method for identifying patients with narrowing of >30% at the site of the anastomosis after coarctation resection. In these cases evaluation by an imaging technique is necessary to confirm the need for surgery.