Flecainide toxicity resulting in pacemaker latency and intermittent failure to capture

John M. Suffredini, Joshua Rutland, Peter Akpunonu, Regan Baum, John Catanzaro, Claude S. Elayi

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Objective: Unusual clinical course Background: Flecainide is a class Ic antiarrhythmic agent used in the treatment of supraventricular and ventricular arrhythmias. It is associated with a potent adverse effect profile however, the effects of flecainide toxicity in the setting of a pacemaker have not been well described. We describe a unique case of flecainide toxicity secondary to acute kidney injury in the setting of a dual-chamber pacemaker, resulting in ventricular capture latency and intermittent failure to capture. Case Report: The patient was a 91-year-old female with a history of atrial fibrillation maintained in sinus rhythm on flecainide, who presented complaining of purple visual disturbances and syncope. She was found to be hypotensive and bradycardic, with a heart rate between 30 to 40 beats per minute. Lab work was notable for creatinine at 2.12 mg/dL. A 12-lead ECG demonstrated atrial and ventricular pacing with severely widened QRS complex and a significant latency between the pacemaker ventricular spike and the ventricular capture. The pacemaker was interrogated, revealing a significant increase in ventricular threshold from 0.75 V at 0.5 ms at baseline to 5.0 V at 1 ms to obtain consistent capture. After multiple boluses of IV sodium bicarbonate, the QRS acutely narrowed, latency interval improved, and consistent pacing capture was achieved. The flecainide level drawn on arrival was 3.09 mcg/mL. Conclusions: Flecainide increases the ventricular capture threshold for pacemakers. Toxicity in these patients may present with pacemaker ventricular capture latency or failure to capture.

Original languageEnglish
Pages (from-to)1279-1283
Number of pages5
JournalAmerican Journal of Case Reports
Volume20
DOIs
StatePublished - 2019

Bibliographical note

Publisher Copyright:
© Am J Case Rep, 2019.

Keywords

  • Acute Kidney Injury
  • Artificia
  • Drug-Related Side Effects and Adverse Reactions
  • Flecainide
  • Pacemaker

ASJC Scopus subject areas

  • General Medicine

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