02292nas a2200181   4500000000100000008004100001100001400042700001800056700001800074700001300092700001400105245011900119250001500238300001200253490000700265520179200272020004602064       2011                            d1 aAlhous M.1 aBroadhurst P.1 aHillis Graham1 aSmall G.1 aHannah A.00aImpact of temporary right ventricular pacing from different sites on echocardiographic indices of cardiac function  a2011/07/19  a1738-460 v133 a<p>
AIMS: To assess the impact of pacing from different right ventricular (RV) pacing sites on left ventricular (LV) function. Chronic apical RV pacing may induce heart failure. To reduce this RV, mid-septum and outflow tract are suggested as alternative pacing sites. We therefore assessed cardiac performance during temporary RV pacing from apical vs. mid-septum or outflow tract sites, using echocardiography and electrocardiography. METHODS AND RESULTS: Patients scheduled for a permanent pacemaker underwent temporary pacing in dual-chamber mode (DDD) and with atrio-ventricular delay optimized. The ventricular lead was moved to either the RV apex, mid-septum or outflow tract. Comprehensive echocardiography was performed in each position. Twenty-two patients completed the study. The baseline data was collected at atrial pacing mode (AAI). QRS duration lengthened with RV apical pacing (97 +/- 22 ms AAI vs. 154 +/- 18 ms RV apical, P &lt; 0.001) and shortened with mid-septum or outflow tract pacing (147 +/- 14 ms RV mid-septum and 136 +/- 16 ms RV outflow tract, P = 0.001 and P &lt; 0.001, respectively, vs. RV apical). Right ventricular apical pacing was associated with reductions in stroke volume and LV ejection fraction (54 +/- 6% AAI vs. 48 +/- 5% RV apical, P = 0.001). Right ventricular mid-septum (52 +/- 5%) and outflow tract (54 +/- 6%) pacing improved LV ejection fraction in comparison with apical pacing (P &lt; 0.01 for both). Pacing at all sites induced dyssynchrony. In comparison with RV apical pacing dyssynchrony was reduced by mid-septum or outflow tract pacing. CONCLUSIONS: Right ventricular pacing at the mid-septum or outflow tract results in narrower QRS complexes, less dyssynchrony, and better LV systolic function than RV apical pacing.
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  a1532-2092 (Electronic)1099-5129 (Linking)