[Ventricular tachycardia due to branch to branch re-entry]

Ventricular tachycardia due to branch to branch re-entry constitutes a rare clinical entity. This circuit is remarkable by the fact that it is made up of the branches or hemi-branches of the bundle of His bifurcation. They occur under specific conditions, with a combination of left ventricular dilatation and atrioventricular or intraventricular conduction defects. They are also very often found in Steinert's disease. A positive diagnosis can sometimes be difficult and relies on a variety of factors. Recording of the His potential shows His activity preceding each ventriculogram, and variations in spontaneous cycles between 2 ventriculograms preceded by variations between the 2 His potentials. Atrial capture without modification of the QRS is possible, but fusion excludes the diagnosis. Drug therapy is only slightly effective, and the best treatment is ablation of the right branch of the bundle of His, which stops the tachycardia definitively.