[Narrow QRS tachycardia].

Narrow QRS tachycardia are supraventricular tachycardia, atrial tachycardia or junctional tachycardia. The diagnosis is done with the ECG, after identification of atrial activation, eventually after vagal manoeuvres, and transoesophageal recordings. DC Choc, atrial pacing, or antiarrhythmic drugs can do interruption. All atrial tachycardia must be anticoagulated prior regularisation. There is seldom an emergency for regularisation, as drugs can always slow the ventricular rate down. Prevention of relapses uses oral antiarrhythmic drugs, sometimes pacing. Most of these tachycardia can be cured by catheter ablation, essentially flutter and junctional tachycardia.