Torsades de pointes을 동반한 Liddle 증후군 1예

Abstract

Liddle syndrome is a rare cause of hypokalemic hypertension and caused by renal tubular sodiurn channel defect resulting in excessive sodium absorption, potassium wasting and metabolic alkalosis. Clinically this syndrome resembles the primary aldosteronism, however, aldosterone and renin secretion are markedly suppressed due to chronic state of volume expansion. This syndrome is transmitted in an autosomal dominant pattern. We have experienced a case of Liddle syndrome, a 74 years old female accompanying severe hypokalemia, long-standing hypertension, metabolic alkalosis and suppressed aldosterone and renin level in serum and urine. She had a history of arrhythmia, torsades de pointes, of unknown cause. We believe that the arrhythmia resulted from severe hypokalemia secondary to this syndrome. Two of her siblings died suddenly, probably from cardio-, cerebrovascular accidents. Five her offspring needed to be evaluated for this syndrome due to its autosomal dominant inheritance. Endocrinologically there was no clue for us to seek other diseases of enzyme deficiency needed in aldosterone synthesis. Once the diagnosis of Liddle syndrome was suspecti, we treated her with amiloride 5mg/day for several days. Thereafter metabolic abnormalities including persistent hypertension, not responded to conventional parenteral potassium replacement and antihypertensive drugs, were reversed and normalized until now. We believe that in some of patients of secondary hypertension of unknown cause, Liddle syndrome should be ruled out, and that the incidence of this syndrome has been underes- timated due to lack of suspicion.