Bradycardia Induced by Hyperkalemia in Older Patients Is Careful about Sick Sinus Syndrome

Abstract

Background: Recently, we had experience of repeat bradycaria patients induced by hyperkalemia with administrating Renin-Angiotensin-Aldosterone system inhibitors (RAAS-I). Aim: We discussed about clinical characteristic of severe bradycardia induced by hyperkalemia (hyperK bradycardia). Method: We researched the patients who visited our division reasoned for hyperK bradycardia during April 1, 2004 to April 30, 2011. Researching items were clinical characteristic, value of serum potassium and serum creatinine, electrocardiogram findings, treatment, and clinical course. Result: Nineteen patients carried into our division in emergency. Their average age was 82 years old, the average date of serum potassium and creatinine on visiting time was 7.4 mEq/L and 2.46 mg/dl. Electrocardiogram findings were followed, sinus arrest: 15 cases, sinus bradycardia: 3 cases, atrioventricular block: 1 case, widening QRS: 7 cases. RAAS-I was administrated in 16 cases. Seven patients needed emergent dialysis. Three patients needed temporary pacing. Most patients recovered within 24 hours. Recurrence was happened in 6 cases. Four patients of recurrence cases did not take RAAS-I. 2 cases were implanted Pacemaker. One patient already had pacemaker. Discussion: hallmark of hyperK bradycardia with administrating RAAS-I is that the degree of renal dysfunction and hyperkalemia is mild. Most patients recovered quickly, but one fourth of patients had recurrence or necessary of pacemaker without RAAS-I. The patients who complicate bradycardia induced by mild hyperkalemia have possibility of sick sinus syndrome. RAAS-I awakes latent sick sinus syndrome in older people.