Syncope in patients with atrial flutter during treatment with class Ic antiarrhythmic drugs.
We describe 2 atrial flutter (AFL) patients with syncope during treatment with class Ic antiarrhythmic drugs. During the syncope, 1:1 atrioventricular (AV) conduction during AFL preceded a wide QRS tachycardia. The class Ic drugs, flecainide and pilsicainide, slowed the atrial rate, resulting in AFL with 1:1 AV conduction, and the width of the QRS complexes became wider during the tachycardia. Syncope was abolished after successful radiofrequency catheter ablation of the AFL. These potential proarrhythmic effects of the class Ic drugs should be taken into account in AFL patients, and concomitant use of beta-blocking agents would be critical to prevent proarrhythmias.
First Department of Internal Medicine, School of Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
M
M
Kawabata
K
K
Hirao
T
T
Horikawa
K
K
Suzuki
K
K
Motokawa
F
F
Suzuki
K
K
Azegami
K
K
Hiejima
D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001282:Atrial Flutter / Q000150:complications* / Q000188:drug therapy* / Q000503:physiopathology; D017115:Catheter Ablation; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D015444:Exercise / Q000502:physiology; D005424:Flecainide / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D008012:Lidocaine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D013575:Syncope / Q000150:complications* / Q000503:physiopathology; D013610:Tachycardia / Q000503:physiopathology / Q000628:therapy
D000889:Anti-Arrhythmia Agents; D008012:Lidocaine; C042288:pilsicainide; D005424:Flecainide