Fast and furious: flecainide toxicity presenting as monomorphic ventricular tachycardia

Flecainide toxicity-Clinical diagnosis and management of an urgent condition

Clinical suspicion, clinical presentation, and electrocardiogram can help clinicians diagnose flecainide toxicity. Currently, there are no guidelines for the management of patients with flecainide toxicity. Sodium bicarbonate, lipid emulsion therapy, and extracorporeal life support have been used in this setting. Amiodarone and lidocaine can be used for the management of wide QRS complex tachycardias in hemodynamically stable patients with flecainide toxicity.

Flecainide toxicity with high pacemaker capture thresholds and associated takotsubo syndrome

We describe a case of a woman in her 80s with persistent atrial fibrillation (AF) despite being on flecainide who was admitted for AF with rapid ventricular response. Attempts with direct-current cardioversions were unsuccessful despite increased doses of the antiarrhythmic therapy. At atrioventricular (AV) nodal ablation, very high right ventricular capture thresholds resulted in abortion of the procedure as back-up ventricular pacing could not be assured with adequate margin for safety. Shortly following the electrophysiology (EP) study, the patient developed cardiogenic shock with new apical left ventricular regional wall motion abnormality suggestive of apical ballooning and a toxic-appearing wide QRS complex electrocardiogram (EKG). The patient was successfully treated with sodium bicarbonate infusion for presumed flecainide toxicity. The regional wall motion abnormality and EKG changes resolved along with normalisation of capture thresholds after 2 days of treatment. The patient underwent an uncomplicated successful AV nodal ablation several weeks later.

First Case of Acute Poisoning with Amiodarone and Flecainide in Attempted Suicide Successfully Managed with Lipid Emulsion Therapy in the Emergency Department: Case Report and Literature Review

Acute antiarrhythmics poisoning represents a challenge in the Emergency Department (ED). These patients often develop malignant arrhythmias in need of exceptional therapeutic measures in the ICU. We report a 47-year-old patient admitted to the ED 5 h after the ingestion of a large dose of amiodarone and flecainide in a suicide attempt. During their ED stay, the patient developed signs of cardiotoxicity evidenced by electrocardiogram and ventricular arrhythmias. The toxicological results showed a level of 4.8 mg/L amiodarone and 2.98 mg/L flecainide. He was successfully treated in the ED using a large dose of sodium bicarbonate and lipid emulsion therapy. After hospital admission, he remained stable, with no need for exceptional therapeutic measures such as mechanical circulatory support, cardiac pacing or ECMO. We emphasize the importance of an early start of pharmacological therapies in the ED, which might improve the outcome in antiarrhythmic acute poisoning.