Optimization of Right Ventricular Lead Position in Cardiac Resynchronisation Therapy

BACKGROUND: The benefit of biventricular pacing (BiV) may be substantially affected by optimal lead placement. AIM: To evaluate the importance of right ventricular (RV) lead positioning on clinical outcome of BiV. METHODS AND RESULTS: A total of 99 patients with symptomatic heart failure and implantation of BiV system were included. Position of the left-ventricular (LV) lead was selected based on timing of local endocardial signal within the terminal portion of the QRS complex. RV lead was preferably positioned at the midseptum (n=74, RVS group) where the earliest RV endocardial signal was recorded. A subgroup of patients had RV lead placed in the apex (n=25, RVA group). NYHA class, maximum oxygen-uptake (VO(2)max), LV end-diastolic diameter (LVEDD, mm) and ejection fraction were assessed every third month. A trend towards greater improvement in NYHA class and significant increase in VO(2)max was present in the RVS group. Moreover, a significant decrease in LVEDD (DeltaLVEDD) was observed in the RVS group only (-3.4+/-6.5 mm versus +1.7+/-6.4 mm in RVA group at 12 months, p=0.004). No significant correlation between the degree of DeltaLVEDD and QRS narrowing induced by BiV was found. LVEDD reduction was predominantly present in dilated cardiomyopathy. CONCLUSIONS: Midseptal positioning of the RV lead appears to promote reverse LV remodelling during cardiac resynchronisation therapy.