Abstract 2164: Right Ventricular Apical Pacing Results in Better Overall Echocardiographic Outcomes than Non-Apical Right Ventricular Pacing
We recently reported that right ventricular (RV) pacing results in long term left ventricular (LV) dysfunction along with worsened mitral and tricuspid regurgitation (MR, TR). Although a few small studies suggest that RV apical (RVA) pacing produces worse LV dyssynchrony compared with other RV (non-RVA) pacing sites, we aimed to determine if long term outcomes were better in non-RV apical compared to RV apical pacing.
Methods: Consecutive patients presenting for first pacemaker (PM) placement with pre- and post device echocardiograms (TTE) and chest x-rays (CXR) were identified from a prospectively collected clinical database from 1996 –2007 and retrospectively reviewed. Left ventricular ejection fraction (LVEF), MR and TR were determined from pre-PM, 1st post-PM and last post-PM TTE. Lead placement was determined from post-PM CXR. Independent and paired T tests along with logistic regression were used for analysis.
Results: Among 446 patients, 242 had RVA and 204 non-RVA leads. Mean age was 69.58±13.2 yrs with baseline LVEF of 50.0±13.2%. First and last echos were obtained a mean of 1 and 2.6 yrs after PM implants, respectively. Comparing to baseline echos, in RVA leads, LVEF worsened by 5.3% (p=0.0001) and 6.0% (p=0.0001), MR decreased by 0.03 (p=0.61) then increased by 0.04 (p=0.51), and TR increased by 0.12 (p=0.10) and 0.23 (p=0.004) on 1st and last echos, respectively. In non-RVA leads, LVEF worsened by 4.6% (p=0.0001) and 5.1% (p=0.001), MR worsened by 0.19 (p=0.004) and 0.25 (p=0.0001), and TR worsened by 0.27 (p=0.001) and 0.52 (p=0.0001). When compared to RVA patients, non-RVA patients had more worsening in MR (p=0.01 and 0.02) and TR (p=0.1 and 0.01). After adjustment for comorbidities and age, RV lead position did not independently predict worsening of LVEF. Independent predictors of worsening LVEF included higher baseline LVEF (p=0.0001), a diagnosis of primary cardiomyopathy (p=0.03), and older age (p=0.06).
Conclusion: Non-RV apical leads do not appear superior to RV apical lead positioning. Non-RV apical positioning was associated with worsening in MR and TR compared with RV apical positions.