[Can 1/1 atrial flutter be foreseen by class I anti-arrhythmics?].
1/1 atrial tachycardia or "quinidine" flutter under class I antiarrhythmic drugs is a serious complication of these agents which, unfortunately, cannot be anticipated. The aim of this study was to review the cases of 11 patients who had suffered this complication of class I antiarrhythmic therapy to see if it could have been prevented. All drugs of this class were included. The 11 subjects were aged 57 to 78: 7 had no apparent underlying cardiac disease and the others had valvular (n = 1), hypertensive (n = 1) and ischaemic (n = 2) heart disease. They were treated for episodes of paroxysmal atrial fibrillation or tachycardia. In the absence of treatment, 7 patients had a short PR interval on the ECG (PR between 0.11 and 0.14 s). In the other 4, the PR interval was normal (0.16 to 0.20 s), but the P wave was widened with appearances of left atrial hypertrophy or an intra-atrial conduction defect. High amplification ECG performed in 3 patients showed continuity of atrial and ventricular depolarisation. Atrial stimulation showed excellent nodal conduction with a Wenckebach point of 200/min. The authors conclude that a short PR interval is predisposing factor to 1/1 atrial tachycardia with class I antiarrhythmics. High amplification ECG which allows identification of the end of the P wave with respect to the QRS complex could help identify subjects at risk when the P wave is widened and that, consequently, the PR interval appears to be normal.
Brembilla-Perrot
B
B
Service de cardiologie A, CHU de Brabois, Vandoeuvre.
Terrier de la Chaise
A
A
Jacquemin
L
L
Beurrier
D
D
Houplon
P
P
Louis
P
P
Danchin
N
N
D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000009:adverse effects*; D001282:Atrial Flutter / Q000139:chemically induced* / Q000503:physiopathology / Q000628:therapy; D004206:Disopyramide / Q000008:administration & dosage / Q000009:adverse effects*; D004562:Electrocardiography; D005260:Female; D005424:Flecainide / Q000008:administration & dosage / Q000009:adverse effects*; D006329:Heart Conduction System / Q000187:drug effects; D006801:Humans; D007093:Imidazoles / Q000008:administration & dosage / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011405:Propafenone / Q000008:administration & dosage / Q000009:adverse effects*; D011802:Quinidine / Q000008:administration & dosage / Q000009:adverse effects*; D012307:Risk Factors
D000889:Anti-Arrhythmia Agents; D007093:Imidazoles; D011405:Propafenone; D004206:Disopyramide; D011802:Quinidine; D005424:Flecainide; C032151:cifenline