[An accelerated idioventricular rhythm and sports activity. Comments on a clinical case and a characterization of the arrhythmia].

In the evaluation of an accelerated idioventricular rhythm (AIVR) case presented by an athlete, even though considered qualified for agonistic sport practice in compliance with the COCIS protocol, the authors made some considerations relative to such type of arrhythmia. AIVR are characterized by a wide oscillation of frequency (from 40 to 120 b/min) and are distinguished as active AIVR when the ventricular center exceeds the discharge frequency in a non depressed sinusal activity; and it's passive AIVR when an automatic ventricular center substitutes the physiological pacemaker in the presence of sinusal bradycardia. This leads to think that it could be two different phenomenons. The first is characterized by a low frequency and is determined by the activation of some automatic cells located under the His bundle, and the second arises with the extrasystolic modality. Moreover, AIVR manifest a parasystolic type of behaviour that complicates the diagnostic differentiation. Therefore it can be considered that the arrhythmia of ventricular genesis (AIVR, ventricular tachycardia, parasystole) represents the varied expression of the same electrogenic substratum with different discharge potentiality. Thus was formulated the proposal of unifying the ventricular rhythms in one group which includes: rhythm of ventricular escapement, AIVR, parasystole and ventricular tachycardia.