Secondary Hypertension: Can it Result from Two Different Causes?

Background: In Portugal hypertension affects around 13% of all children. Essential hypertension is the commonest. Renovascular disease is an uncommon, but important cause of hypertension in children, which includes renal artery stenosis (RAS).

Case-Report: A two-year-old girl with a complex cyanotic cardiopathy (type B Aortic branch interruption, subaortic stenosis and a nonrestrictive intraventricular communication) submitted to two correction surgeries is admitted with fever, cough, rhinorrhea and anorexia. At observation she had a good general condition, with cyanotic lips and nails and no signs of respiratory distress and she was hospitalized for surveillance. During the hospitalization serial BP measures revealed hypertensive peaks and she initiated antihypertensive therapy with captopril and furosemide, with poor BP control. An echocardiogram was performed excluding an aortic recoartation and a renal ultrasonography revealed a small right kidney with diminished corticomedullar differentiation. During hospitalization there was no significant decrease in BP raising suspicion of renovascular etiology. A magnetic resonance angiography was performed revealing a stenotic right renal artery and distal aorta in “sack bottom” – consistent with important vascular malformation. Captopril was progressively stopped, a calcium channel blocker was initiated and later a beta-blocker was added to BP control. After discharge a percutaneous angiography was performed confirming the vascular malformation making it impossible to revascularize. The Tc 99m-MAG3 renal isotope scan was also performed and revealed a right kidney with 36% function. Currently she has a multidisciplinary follow-up and maintains antihypertensive therapy with propranolol and amlodipine, with therapeutic readjustments periodically needed.

Conclusion: Secondary causes for pediatric hypertension are variable, and should be suspected in children with early-onset hypertension. In a child with a repaired aortic coarctation a recoartation must be excluded as the hypertension etiology. Refractoriness to appropriate medical therapy should raise suspicion for renovascular etiology and CT or MRI angiography reveal the diagnosis.