Recurrent syncope attributed to torsade de pointes induced by worsened long QT interval after switching from peritoneal dialysis to hemodialysis: A case report

Abstract

A 46-year-old female patient with chronic renal failure was admitted to our hospital to switch from peritoneal dialysis (PD) to hemodialysis (HD). She reported no history of syncope, but she experienced syncope with palpitation during and after HD following discharge. The 24-h Holter electrocardiography (ECG) detected no arrhythmia-inducing syncope. She was admitted to our hospital to receive shunting for HD. However, she developed torsade de pointes (Tdp)-induced syncope during HD and immediately received electrical cardioversion. Her 12-lead ECG demonstrated a QTc interval of 557 ms (QT: 457 ms), blood examination revealed 3.5 mEq/L of potassium and 8.5 mEq/L of calcium, and echocardiography showed an ejection fraction of 46 %, which was lower than before. The coronary artery was normal, and temporary right ventricular pacing therapy was immediately performed. Evocalcet was discontinued because it is known to induce long QT, and bisoprolol was initiated. Additionally, her potassium level was corrected. However, long QT in the sinus rhythm did not improve, and daily ECGs detected T-wave changes. Nonsustained Tdp with presyncope developed after HD while pacing off. Thus, an implantable cardioverter defibrillator was implanted. We present a case of recurrent Tdp-induced syncope related to worsened long QT after switching from PD to HD.

Learning objective

Prolonged QT intervals are caused by various factors and are more prevalent in patients undergoing hemodialysis (HD). The present case developed torsade de pointes-related syncope that was induced by worsened, prolonged QT interval after switching to HD. The worsening of long QT is mainly attributed to fluctuation in potassium levels before and after HD. Thus, carefully monitoring the QT interval and changes in the serum potassium level is crucial, particularly, when initiating HD.