Right ventricular bifocal stimulation in the treatment of dilated cardiomyopathy with heart failure
Pachón Mateos, J.C.; Albornoz, R.N.; Pachón Mateos, E.I.; Gimenez, V.M.; Pachón, M.Z.; Santos Filho, E.R.; Medeiros, P.; Silva, M.A.; Paulista, P.P.; Sousa, J.E.; Jatene, A.D.
Arquivos Brasileiros de Cardiologia 73(6): 485-498
1999
ISSN/ISBN: 0066-782X PMID: 10904269 Document Number: 500216
To describe a new more efficient method of endocardial cardiac stimulation, which produces a narrower QRS without using the coronary sinus or cardiac veins. 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 approximately 0) stimulation. 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. 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.