Background The implantation of left ventricular (LV) lead was the most complicated process in the cardiac resynchronization therapy (CRT), the aim of this study was to investigate the availability of a novel Visionwire guide wire in the implantation ofLVlead in CRT.

Methods Five heart failure patients selected for CRT were involved in the study. The pacing threshold, R-wave sensing, phrenic nerve stimulation at local coronary sinus (CS) branch were measured by the Visionwire guide wire and LV lead separately.

Results The pacing parameters were analysed through the Visionwire guide wire and LV lead separately at the 16 CS branches in 5 patients. There was no significant difference between the pacing parameters measured by the two methods. Significant correlation was found betweenLVpacing threshold assessed by the Visionwire guide wire andLVlead (r = 0.90, P < 0.01). Correlation for R wave sensing was also significant (r = 0.67, P < 0.01). The pacing sites accompanied with phrenic nerve stimulation while pacing at 10 V/0.42 ms were similar by the two methods. Visionwire guide wire could be used for local potential electrical mapping. The procedure time for pacing test in a single coronary sinus branch by Visionwire guide wire was much less than that by LV lead (12.4 ± 7.5min vs 18.3 ± 12.2min, P < 0.01).

Conclusions Visionwire guide wire facilitated transvenousLVlead implantation by prediction of pacing parameter and locate the target CS branch quickly. The electrophysiological mapping function of Visionwire guide wire as a unipolar lead might have further potential usefulness.