[Atrio-ventricular nodal reentrant tachycardia--concepts evolution on the propagation of the reentrant wave front].

Atrio-ventricular nodal reentrant tachycardia (AVNRT) is the most common narrow QRS tachycardia. The arrhythmia affects usually patients without any other structural heart disease. AVNRT may be the cause of the broad spectrum of symptoms, ranging from palpitations to clinical signs of impaired coronary and cerebral perfusion. Mechanism responsible for AVNRT is reentry, which involves right and some part of the left atrium. Employed in the early 80's the technique of radiofrequency current (RF) ablation (which allows removal of arrhythmic substrate by modification or destruction of the slow pathway), is safe and a high effective method of treatment in patients with AVNRT.