Resumo

CHIESA, Pedro et al. Miocardiopatía dilatada en la edad pediátrica por marcapasos con estimulación en el ápex del ventrículo derecho. Arch. Pediatr. Urug. [online]. 2008, vol.79, n.2, pp.125-138. ISSN 0004-0584.

Since the beginning of the implementation of this technique, the ventricular pacemaker electrode is usually implanted at the apex of the right ventricle. There is now enough information about the side effects of the desyncronization which determines the risk of having ventricular failure. This problem is under diagnosed particularly in the pediatric age. An analysis of patients that required the implantation of a definitive pacemaker in our pediatric population (n = 85) evaluating those who had an evolution to dilated miocardiopathy without any other cause linked to the form of stimulation is presented. The clinical features, the basic diseases, evolution, therapy adopted and follow up in the first year of treatment is described. One patient was evaluated with Doppler Tissue Color Echocardiogram with Q analysis curves speeds to see the electromechanic desyncronizations and its evolution over time. We studied 7 patients (8%), 3 male who were between 2 and 10 years old at the time of the implant. 3 patients had a congenital complete atrioventricular blockade and 4 had an acquired complete atrioventricular blockade after the cardiac surgery. In 5 of them a VVIR (ventricular sensing and paced) pacemaker was implanted, in 1 a VDD (atrioventricular sensing and ventricular paced) and in 1 a DDD (atrioventricular sensing and paced). In 3 patients the electrode was implanted via the endocardium and 4 via the pericardium. The baseline electrocardiograms showed stimulation of 100% of the QRS (electrocardiography complex indicating ventricular depolarization) with 179 ms of duration. (160-200 ms). The deterioration of its functional class was evident after 2 to 7 years of the implant (average 3 years). All had normal function and diameters without dilation of left chambers and there was a 16% drop in the ejection fraction (11-19%). 3 patients underwent a heart transplant and in 3 patients the pacemaker was replaced by a cardiac resyncronization treatment. The remaining died waiting for a donor. The tissue Doppler color echocardiogram with velocity curve analysis showed clearly the desyncronization values both intra and interventricular, which disappeared once the patient underwent the resyncronization therapy. Dilated miocardiopathy induced a pacemaker stimulation located at the apex of the right ventricle is not a rare event. It occurs in patients stimulated 100%, with wide QRS and after a certain period of time since the implant

Palavras-chave :  VENTRICULAR DYSFUNCTION, LEFT;  CARDIOMYOPATHY, DILATED; PACEMAKER, ARTIFICIAL; CHILD.

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