Right ventricular bifocal stimulation in the treatment of dilated cardiomyopathy with heart failure.
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 approximately 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.


CONCLUSIONS
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.
Pachón Mateos
J C
JC
Instituto Dante Pazzanese de Cariologia and Hospital do Coraço, São Paulo, SP, Brazil.
Albornoz
R N
RN
Pachón Mateos
E I
EI
Gimenez
V M
VM
Pachón
M Z
MZ
Santos Filho
E R
ER
Medeiros
P
P
Silva
M A
MA
Paulista
P P
PP
Sousa
J E
JE
Jatene
A D
AD
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000628:therapy; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000628:therapy*; D002908:Chronic Disease; D004567:Electrodes, Implanted; D005260:Female; D006327:Heart Block / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000628:therapy; D010138:Pacemaker, Artificial; D014463:Ultrasonography