A Rare Case Report of Flecainide-Induced Left Bundle Branch Block (LBBB) and Transient Cardiomyopathy

Abstract

Flecainide is an antiarrhythmic agent that has been reported to have numerous cardiotoxic effects, including the development of arrhythmias and the reduction of left ventricular ejection fraction (LVEF). However, it is not commonly reported as a cause for left bundle branch block and cardiomyopathy. In this case report, we present the case of a 67-year-old female patient who developed transient cardiomyopathy and left bundle branch block (LBBB) secondary to flecainide therapy. The patient's condition improved upon cessation of flecainide.

Keywords: cardiomyopathy; chf; congestive heart failure due to flecainide; flecainide; flecainide adverse effects; flecainide possible lbbb; flecainide toxicity; left bundle branch block; pacemaker induced cardiomyopathy; transient nonischemic reversible cardiomyopathy.

Figure 1. 12-lead EKG demonstrated a new left bundle branch block (LBBB) with left axis deviation and a wide QRS complex of 194 milliseconds on admission.

EKG: Electrocardiogram, LBBB: Left bundle branch block

Figure 2. EKG from 2013 was unremarkable and did not show LBBB

EKG: Electrocardiogram, LBBB: Left bundle branch block

Figure 3. Chest radiography demonstrated bilateral diffuse interstitial opacities and interstitial pulmonary edema with central pulmonary vascular engorgement, cardiomegaly, and a dual-chamber pacemaker.

CXR: Chest X-ray

Figure 4. 12-Lead EKG showing QRS complex duration improved from 194 milliseconds to 150 milliseconds after 24 hours following flecainide cessation

EKG: Electrocardiogram

Figure 5. 12-Lead EKG showing QRS complex duration improved from 150 milliseconds to 142 milliseconds after 42 hours following flecainide cessation.

EKG: Electrocardiograms

Figure 6. 12-lead EKG showing QRS complex duration improved from 142 milliseconds to 122 milliseconds after more than 72 hours following flecainide cessation

EKG: Electrocardiogram