PS-BPR03-6: A CASE OF COARCTATION OF THE AORTA THAT DOPPLER ULTRASOUND WAS USEFUL FOR INVESTIGATING THE CAUSE OF ADOLESCENT REFRACTORY HYPERTENSION

Abstract

A 17-year-old female was referred to our department with hypertension refractory to medical treatment. When she presented to the otolaryngologist 3 years earlier for dizziness, her systolic blood pressure was 170 mmHg. On physical examination, her blood pressures in right and left arms were 193/99 and 196/106 mm Hg, respectively. Also, a systolic ejection murmur of grade 2/6 was present at the left upper sternal border. She was prescribed cilnidipine 20 mg/day and nifedipine CR 40 mg/day, but her blood pressure was 160/90 mmHg. Plasma renin activity was 5.2 ng/ml/h, and serum aldosterone was 210.4 pg/ml, so renovascular hypertension was suspected. However, contrast-enhanced 3-dimensional computed tomography (3DCT) of the both renal arteries showed no stenosis. On the other hand, renal doppler ultrasound revealed a slow rise in systolic blood flow waveform in both renal arteries and intrarenal arteries. This indicates that the vessel upstream of the measurement site is stenotic. The similar blood flow waveform was observed in the abdominal aorta, suggesting aortic stenosis upstream of the abdominal aorta. 3DCT of the thoracic aorta revealed a significant coarctation of the thoracic aorta distal to the origin of the left subclavian artery. We diagnosed her as coarctation of the aorta, and performed a descending aortic replacement procedure. As a result, her blood pressure decreased to 130/80 mmHg under cilnidipine 20 mg/day. The waveform of both renal arteries, intrarenal arteries and abdominal aorta became a normal pattern by doppler ultrasound. Hypertension in adolescent is uncommon. As secondary causes are more commonly found in this age group than in older adults, aortic coarctation should be considered. Early diagnosis and treatment are essential for the prevention of morbidity and mortality from premature cardiovascular complications. Here, we described a case of coarctation of the aorta that doppler ultrasound was useful for investigating the cause of adolescent refractory hypertension.