Comparative study of electrophysiological parameters of endocardial septal stimulation with conventional endocardial pacing. / Estudo comparativo dos parâmetros eletrofisiológicos da estimulação endocárdica septal com a estimulação cardíaca endocárdica convencional.

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

02/05/2012

RESUMO

Background: The conventional endocardial pacing in right ventricular apex or subtricuspid area causes significant QRS enlargement and important left ventricular desynchronization with ventricular function damage. By the introduction of RV bifocal pacing and the need of a less deleterious ventricular stimulation right ventricular septal pacing has been increasingly used. However, despite rare, some authors have reported high pacing thresholds and low R wave in septal pacing. Objective: To compare the electrophysiological parameters of the apical and septal stimulation in the same patient, seeking for any difference that could affect the choice of the pacing point. This is not a resynchronization study however it has the aim to search for for a better monofocal ventricular pacing. Materials and methods: Prospective controlled study of 25 symptomatic patients (67.2 ± 9 years old, 10 [40%] female, 15 [60%] male) having permanent atrial fibrillation with high degree AV block and classical pacemaker indication. The etiologies were 9 (36%) aging, 8 (32%) coronary disease, 7 (28%) Chagas disease and 1 (4%) valvar cardiopathy. There were used active fixation leads both in septal and in apical locations. The generators were Biotronik Philos II DR and Entovis DR. There were measured and compared pacing thresholds, impedance and R wave uni and bipolar during implantation (direct measurement) and after six months of follow-up (telemetry measurement). Results: During implantation, the septal vs apical mean pacing threshold were respectively 0.73 vs 0.74V (unipolar) and 0.73 vs 0.78V (bipolar). Mean R wave septal vs apical were 10 vs 9.9 mV (unipolar) and 12.3 vs 12.4mV (bipolar). The mean impedance septal vs apical were 579 vs 621? (unipolar) and 611vs 629? (bipolar). All septal vs apical comparisons were non-significant (p >0.1, two-tailed paired t-test). After six months the mean pacing threshold septal vs apical were respectively 0.5 vs 0.72V (unipolar) and 0.71 vs 0.87V (bipolar). The mean R wave septal vs apical were 11.4 vs 9.5mV (unipolar) and 11.2 vs 12mV (bipolar). The mean impedance septal vs apical were 423 vs 426? (unipolar) and 578 vs 550? (bipolar). Only the unipolar septal vs apical mean threshold had significant difference (p = 0.02) with lower septal value. Conclusion: This study showed no significant difference between electrophysiological septal and apical pacing parameters when the 29 comparison is done in the same patient. By this way there are no restrictions for the right ventricular septal pacing. Despite being a non-resynchronization study it may contribute for chosen a less deleterious right ventricular monofocal pacing.

ASSUNTO(S)

bradicardia bradycardia marca-passo pacemaker ressincronização resynchronization

ACESSO AO ARTIGO

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