José Carlos Pachón Mateos et al. Remy Nelson Albornoz Enrique Indalécio Pachón Mateos Vera Márcia Gimenez … Juán Carlos Pachón Mateos Maria Zélia Cunha Pachón Eusebio Ramos dos Santos Fº Paulo de Tarso Jorge Medeiros Marco Aurélio Dias da Silva Paulo Paredes Paulista José Eduardo Moraes Rêgo Sousa Adib Domingos Jatene
OBJECTIVE: To describe a new more efficient method of endocardial cardiac stimulation, which produces a narrower QRS without using the coronary sinus or cardiac veins. METHODS: We studied 5 patients with severe dilated cardiomyopathy, chronic atrial fibrillation and AV block, who underwent definitive endocardial pacemaker implantation, with 2 leads, in the RV, one in the apex and the other in the interventricular septum (sub pulmonary), connected, respectively, to ventricular and atrial bicameral pacemaker outputs. Using Doppler echocardiography, we compared, in the same patient, conventional (VVI), high septal (“AAI”) and bifocal (“DDT” with AV interval ~ 0) stimulation. RESULTS: The RV bifocal stimulation had the best results with an increase in ejection fraction and cardiac output and reduction in QRS duration, mitral regurgitation and in the left atrium area (p <= 0.01). The conventional method of stimulation showed the worst result. CONCLUSION: These results suggest that, when left ventricular stimulation is not possible, right ventricular bifocal stimulation should be used in patients with severe cardiomyopathy where a pacemaker is indicated.