Abstract: SA-PO977

Dialysis Related Pacemaker Failure

Session Information

Category: Nephrology Education

  • 1302 Fellows and Residents Case Reports

Authors

  • Ogbonnaya-Odor, Chinonye Chika, University of Texas Houston, Houston, Texas, United States
  • Waguespack, Dia Rose, UTHealth, Houston, Texas, United States
  • Ziaolhagh, Ali, University of Texas, Housotn, Texas, United States
Background

Dialysis is used in the treatment of electrolyte disorders. Electronic pacemakers are used in the management of arrhythmia’s. Failure to capture is a term describing electronic pacemaker pacing, without desired cardiac response. We present a case of unstable bradyarrhythmia due to pacemaker failure to capture, resulting from transient electrolyte changes during hemodialysis.

Methods

An 87-year-old man with CKD III, bradycardia requiring pacemaker placement, and severe hypercalcemia related to left parathyroid adenoma, presented with altered mental status, constipation, and acute kidney injury. He was treated with calcitonin, crystalloids, cinacalcet and hemodialysis. On day 7 parathyroidectomy was performed. Post-surgery, Intact parathyroid (iPTH) trended down rapidly, ionized (iCa) levels gradually decreased, but Creatinine (Scr) increased, and patient became anuric. Labs showed Sodium (Na): 139 mEq/L Potassium (K): 3.9 meq/L Chloride (Cl):102, Bicarbonate (CO2): 21 q/L, iCa of 1.50 mmol/L, Magnesium (Mg):2.4 Mg/dL, Phosphorus: 4.1 Mg/dL. Hemodialysis (HD) was performed with dialysate containing Na: 140 Meq, K: 2.0 Meq, Ca: 1.5 mEq, CO2: 35 mEq. Vitals were stable. After 2 hours of dialysis, patients' heart rate decreased to 20-30 bpm, pacemaker failure to capture was noted on telemetry.Blood pressure (BP) decreased to 75/54, and he became less responsive. HD was discontinued. He was treated with intravenous albumin, crystalloid bolus and atropine with poor response in BP and HR. Transcutaneous pacing was initiated, with appropriate response. Labs revealed iCa: 1.20 mmol/L, K: 3.1 mEq/L, Mg: 1.1 mEq/L, hematocrit: 27%, glucose of 127mg/dL. Pacemaker was interrogated. Findings revealed an acute increase in cardiac pacing threshold during event, which normalized within the next 2 hours. Mg was replaced with intravenous magnesium sulfate.

Conclusion

Hypocalcemia affects cardiac conduction by increasing phase 2 of cardiac repolarization. The effects are bradycardia and prolonged QTc. Hypomagnesemia can produce similar effects.In this patient, electrolyte flux during dialysis led to pacemaker malfunction. Appropriate treatment for this patient included electrolyte replacement and changing pacemaker to asynchronous pacing, by placing a magnet on the pacemaker engine.