A single introduction electro-catheter to be used for permanent, semipermanent or termporary cardiac stimulation through the Coronary Sinus. Said electro-catheter featuring the possibility to stimulate from one to four cardiac chambers, according to the preferred stimulation protocol, either in sequence or simultaneously, said catheter being characterized by part or all of the following features. A) A configuration such to be able to support one, two three or four electrodes, placed on separated segments whenever necessary, said electrodes being placed in contact with the targeted cardiac chambers. B) A stent structure is permanently tied to the electro-catheter, in its distal portion close to the electrode bearing portion of said lead. C) The stent structure, and the mated electro-catheter segments will be kept in their compressed form while introduced in the access vein. Such compressed form being of an acceptable diameter for trasvenous introduction. D) Once the system is advanced to the targeted position in the Coronary Sinus, the stent structure will be expanded, dilating the bifurcation of the lead and pushing the electrodes against the cardiac walls. E) A suitable pre-curvature (40.degree. . . . 90.degree.) is intrinsically given to the lead body along its length, so to allow for an easy positioning of the whole structure in the Coronary Sinus, as described in FIG. 2.