Refractory long QT syndrome and the role of left cardiac sympathetic denervation

摘要

A 43-year-old woman, the proband, experienced syncope at age 9 and was diagnosed with long QT syndrome (LQTS) at age 11 years. Treatment with propranolol 40 mg three times daily (t.d.s.) rendered her asymptomatic. Her husband, three brothers and parents are all unaffected by LQTS. She has four sons; the eldest is asymptomatic; however, the younger three sons are severely symptomatic (Fig. 1). The second son is 19 years old and has a corrected QT interval (QTc) of 490 ms. Diagnosis of LQTS was made at birth because of neonatal bradycardia and a prolonged QTc interval. Initial treatment was with propranolol 1 mg/kg t.d.s. He remained asymptomatic until the age of 8 years, then presented with dizziness and was found to have episodic sinus bradycardia and torsade de pointes (TdP). An implantable cardioverter-defibrillator (ICD) was implanted, and he remained stable on beta-blocker therapy.