[Electrophysiological evaluation of ventricular tachycardia by right and left ventricle endocardial mapping (author's...

Eight patients with ventricular tachycardia (VT) have been studied by unipolar recordings of 7 endocardial points of the left ventricle (LV) and 6 endocardial points of the right ventricle (RV) in order to record if possible: 1) where the VT arose; 2) a continuous electrical activity during the sistodiastolic phase of the intracardiac ECG [late potentials (LP)], suggesting the reciprocating mechanism of VT. All the patients underwent cardiac catheterization with left and/or right ventriculography. A coronary arteriography was performed in four cases. Four patients had no evidence of heart disease; one patient had aortic stenosis; one patient had two vessels coronary disease and extensive ipo-akinesis of the LV; two patients had dyskinetic areas of the RV. In all the cases it was possible to identify where the VT arose by means of recordings during spontaneous VT episodes (the sites of origin of the VTs were stated in the points where the intracardiac QRS began with an intrinsic deflection), or by means of asyncronous ventricular stimulation (the sites of origin of the VTs were stated in the points where the ventricular stimulation reproduced a surface ECG similar to the one recorded during spontaneous VT). The fact that the site of origin of the VT is never in the same point of the earliest endocardial activation during sinus rhythm and the fact that this site is located in a zone with rich terminations of the conduction system, suggest the reciprocating VT may develop in a circuit, with both conduction and myocardial tissue.