A novel fluoroscopic method of measuring right-to-left interlead distance as a predictor of reverse left ventricular remodeling after cardiac resynchronization therapy.

Purpose: In spite of technological breakthroughs, the choice of a suitable location for the coronary sinus (CS) lead in biventricular implants is still mostly empiric. The aim of this study was to investigate the utility of a radiological index-the distance between the right ventricular (RV) and CS lead tips on fluoroscopic recordings, measured by means of a new method-as a tool for selecting the most profitable left ventricular (LV) lead position.
Methods: Forty-nine consecutive patients (36 male, 13female; mean age 63 ± 19 year), in whom the LV electrode was implanted in a lateral/postero-lateral position in the CS, were evaluated immediately after implantation. The fluoroscopic distances between the RV and LV lead tips were calculated off-line in antero-posterior (2DAP) and latero-lateral (2DLL) projections by means of integrated software.
Results: On 1-year follow-up evaluation, 53 % patients were classed as responders (R) (>15 % reduction in LV end-systolic volume) and 47 % as non-responders (NR). On receiver-operating curve analysis, 2DAP and 2DLL showed cut-off values of 81 mm and 51 mm, respectively. In discriminating between R and NR, 2DAP >81 mm displayed 95 % specificity and 74 % sensitivity, while 2DLL >51 mm displayed 74 % specificity and 92 % sensitivity. On multivariate analysis, the cut-off values of 2DAP and 2DLL were significantly predictive of R to CRT.
Conclusions: In our single-center prospective experience, RV-LV interlead distance measured by means of a novel method on fluorographic recordings correlated with CRT response. The use of this method as an intra-operative guide to identifying suitable lead placement in the CS needs evaluating on-line and on a large scale.