L/N-type Ca²⁺ channels blocker cilnidipine ameliorated the repolarization abnormality in a chronic hemodialysis patient

A 53-year-old woman with end-stage renal disease and hypertension, who had received regular artificial hemodialysis for 10 years, has been treated with candesartan in a dose of 8 mg/day against her hypertension, but premature ventricular contractions were often observed during the hemodialysis. QT interval was 445 ms before hemodialysis, which was prolonged to 515 ms immediately after it, possibly reflecting the presence of reduced repolarization reserve in her heart. Since the blood pressure was often elevated to >160 mmHg before the hemodialysis, a daily dose of an L/N-type Ca²⁺ channels blocker cilnidipine of 5 mg/day was added. Three months later, the electrocardiogram was obtained before hemodialysis, revealing the basal QT interval was shortened to 416 ms. More importantly, in the electrocardiogram recorded immediately after the hemodialysis, the QT interval was 429 ms, indicating that 3 months administration of cilnidipine may restore the reduced repolarization reserve. As well, we observed that premature ventricular contractions during the hemodialysis had disappeared. Thus, cilnidipine may become a new upstream therapy to reduce the risk of lethal arrhythmias.