[Atrial flutter with 1/1 nodo-ventricular conduction with amiodarone. From physiopathology to diagnosis].
Atrial flutter with 1/1 nodo-ventricular conduction is a classical complication of Vaughan-Williams's Class I antiarrhythmic drugs. The increase of the flutter cycle and weak action of the antiarrhythmic on the atrioventricular node leads to 1/1 conduction of atrial depolarisation to the ventricles. In view of their marked action on the atrioventricular node, this type of pro-arrhythmic effect is very unexpected with Class III antiarrhythmics. The authors report 7 cases of 1/1 atrial flutter with oral amiodarone observed between 1994 and 2001. The patients were 6 men and 1 woman with an average age of 58 +/- 14 years. Four of them had underlying cardiac disease; none were hyperthyroid. The initial arrhythmia was 2/1 atrial flutter (n = 4), 1/1 atrial flutter (n = 2) and atrial fibrillation (n = 1). Treatment was preventive with doses of 400 mg/day associated with carvedilol in one patient and 200 mg/day in another. The other five patients all received loading doses of 9200 +/- 2400 mg over 10 +/- 4 days. The symptoms were palpitations (n = 2) associated in one patient with hypotension, one syncope, one near syncope and one cardiogenic shock. The ventricular cycle of the 1/1 flutter was 287 +/- 33 ms. The QRS duration was 136 +/- 35 ms with ventricular tachycardia-like appearances in 3 cases. An adrenergic trigger factor was noted in 5 patients. One patient required emergency cardioversion. The authors discuss the physiopathology of 1/1 flutter and theoretical diagnostic methods are proposed. In conclusion, amiodarone does not always prevent the occurrence of 1/1 nodo-ventricular conduction in atrial flutter.
Aouate
P
P
Hôpital Jean-Rostand, 39-41, rue Legalleu, 94200 Ivry-sur-Seine. philip.aouate@ch-creil.fr
Elbaz
N
N
Klug
D
D
Lacotte
J
J
Raguin
D
D
Frank
R
R
Lelouche
D
D
Dubois-Randé
J L
JL
Tonet
J
J
Fontaine
G
G
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000638:Amiodarone / Q000009:adverse effects* / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001145:Arrhythmias, Cardiac / Q000188:drug therapy; D001282:Atrial Flutter / Q000139:chemically induced*; D001283:Atrioventricular Node / Q000473:pathology; D005260:Female; D006801:Humans; D007022:Hypotension / Q000209:etiology; D008297:Male; D008875:Middle Aged; D013575:Syncope / Q000209:etiology
D000889:Anti-Arrhythmia Agents; D000638:Amiodarone