Cardiac devices with class 1C antiarrhythmics: a potentially toxic combination

A patient taking regular flecainide for paroxysmal atrial fibrillation presented with broad complex tachycardia and circulatory compromise. With no history of pacemaker insertion and no pacing spikes visible on the ECG, this was presumed to be ventricular tachycardia and treated with electrical card...

Full description

Saved in:
Bibliographic Details
Published in:BMJ case reports 2015-08, Vol.2015, p.bcr2015210598
Main Authors: Apps, Andrew, Miller, Charles Philip, Fellows, Sarah, Jones, Michael
Format: Article
Language:English
Subjects:
80 years
Aged, 80 and over
Anti-Arrhythmia Agents - adverse effects
Anti-Arrhythmia Agents - therapeutic use
Antiarrhythmics
Atrial Fibrillation - drug therapy
Atrial Fibrillation - therapy
Atrial Flutter - drug therapy
Atrial Flutter - therapy
Cardiac arrhythmia
Drug dosages
Electric Countershock
Electrocardiography
Europe (West)
Flecainide - adverse effects
Flecainide - therapeutic use
Heart Atria - physiopathology
Heart Ventricles - drug effects
Heart Ventricles - physiopathology
Humans
Male
Pacemaker, Artificial
Patients
Questioning
Tachycardia - drug therapy
Tachycardia - therapy
Unexpected Outcome (Positive or Negative) Including Adverse Drug Reactions
White
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A patient taking regular flecainide for paroxysmal atrial fibrillation presented with broad complex tachycardia and circulatory compromise. With no history of pacemaker insertion and no pacing spikes visible on the ECG, this was presumed to be ventricular tachycardia and treated with electrical cardioversion, leading to p-wave asystole. An indwelling pacemaker was now recognised and ventricular capture was eventually attained by significantly increasing ventricular lead output. Invasive haemodynamic support was required due to new ventricular systolic dysfunction. Pacing thresholds and ventricular function normalised within 72 h consistent with flecainide toxicity; levels were shown to be toxic. Pacemaker interrogation revealed evidence of an undiagnosed atrial flutter, at presentation this was likely slowed by flecainide toxicity to a rate below the pacemaker mode switch, such that it was tracked in the ventricle at the upper tracking rate (120 bpm). Cardioversion terminated the arrhythmia but raised the capture threshold of the ventricle above the maximum lead output.
ISSN:1757-790X
1757-790X
DOI:10.1136/bcr-2015-210598