Cor Vasa 2008, 50(4):149-154 | DOI: 10.33678/cor.2008.053

Assessing the effect of right ventricular septal or apical pacing on echocardiographic parameters of dyssynchrony in patients with preserved left ventricular function - mid-term follow-up.

Kateřina Lefflerová, Petr Lupínek, Jan Bytešník, Robert Čihák, Renata Krausová, Vlastimil Vančura, Josef Kautzner

Klinika kardiologie, Institut klinické a experimentální medicíny, Praha, Česká republika

Aim of study:
A number of experimental and clinical studies have shown that right ventricular (RV) apical pacing leads to marked asynchrony of ventricular activation. This can result in systolic and diastolic left ventricular (LV) dysfunction. A solution is pacing from alternative RV sites. The study was designed to compare the effect of septal vs. apical pacing using echocardiographic parameters of ventricular dyssynchrony on mid-term follow-up.

Method:
Forty-one patients (31 men, mean age 73 ± 10 years) with advanced AV block and preserved LV ejection fraction (EF > 45%) were included into the study. Patients were randomized to septal or apical pacing at a 2 : 1 ratio. The electrode with active fixation was placed either on the septum or the RV apex. Echocardiography including tissue Doppler echocardiography (TDE) was performed within a week post-implant and at a six-month interval. We assessed parameters of interventricular and intraventricular dyssynchrony. Interventricular mechanical delay (IVMD) was assessed as the difference between pre-ejection left and right ventricular times. Intraventricular LV dyssynchrony was analyzed using TDE data, assessed as the difference in peak velocities of septal and LV lateral wall contraction.

Results:
Immediately after implantation, LV pre-ejection times in the septal and apical pacing groups were 141 ± 22 ms and 148 ± 23 ms, respectively, being 142 ± 30 ms and 151 ± 24 ms, respectively, at six months. IVMD was 20 ± 23 ms with septal pacing and 21 ± 19 ms with apical pacing, with the values being 36 ± 16 ms and 35 ± 21 ms, respectively, at six months. The difference in the peaks of septal and lateral wall contraction was 28 ± 58 ms and 24 ± 55 ms at baseline, respectively, and 39 ± 56 ms and 37 ± 56 ms, respectively, at six months.

Conclusion:
In the present study, no statistically significant difference was demonstrated in patients with preserved LV function between the effects of RV septal vs. apical pacing on parameters of interventricular and intraventricular dyssynchrony acutely or on mid-term follow-up. However, an appreciable interindividual spread in all monitored parameters was observed in both groups.

Keywords: Cardiac pacing; Cardic dyssynchrony; Echocardiography; Lead

Published: April 1, 2008  Show citation