LAUSR

Dr Behar, Dr Rajani, and Dr Rinaldi are thanked for their interest in our recent trial evaluating the clinical benefit of multimodality imaging-guided left ventricular (LV) lead placement in cardiac resynchronization therapy (CRT).1,2 We acknowledge the potential of image integration for improving the precision of LV lead positioning towards a predefined optimal LV pacing site. A validated accurate algorithm for fusion of procedural fluoroscopic venography with pre-implant imaging is required to benefit from such a strategy. Preferably, a pre-implant ‘all-in-one’ imaging modality (e.g. cardiac magnetic resonance imaging) for visualizing myocardial scar, mechanical activation pattern, and cardiac venous anatomy should be performed and accurately integrated with the procedural venography to target the desired level of the optimal cardiac vein. The potential clinical benefit of such an approach remains to be evaluated in a prospective randomized setting. Previous trials investigating the impact of imaging-guided LV lead placement on CRT outcome applied fluoroscopy to guide lead position towards a predefined optimal segment for LV pacing as determined by .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. echocardiography.3,4 Designing the present trial, we acknowledged the inaccuracy and poor reproducibility of fluoroscopy to determine lead position in heart failure patients.5 Accordingly, we performed a pre-implant cardiac computed tomography (CT) to visualize the anatomical relation between available cardiac veins and underlying LV myocardium. Moreover, a three-dimensional reconstruction of cardiac venous anatomy could easily be co-registered with the procedural fluoroscopic venography to identify and target the optimal cardiac vein closest to the predefined optimal myocardial segment for LV pacing. Furthermore, cardiac CT verified final LV lead position according to the myocardial segmentation including relation to the optimal pacing site and pre-implant visualized cardiac veins.1 A LV lead location concordant or adjacent to optimal pacing site is generally considered ideal as reaching a concordant position is constrained by cardiac venous anatomy, lead stability, pacing threshold, and phrenic nerve stimulation. The present trial supports the use of an imaging-guided strategy for LV lead placement. Nevertheless, challenging the need for imaging-guided LV lead positioning, our control group routine approach targeting the LV lead towards a non-apical posterolateral region with late electrical activation resulted in a lead position concordant or adjacent to the optimal pacing site in the vast majority (98%) of patients. Accordingly, other strategies for optimizing LV lead positioning should be investigated. The alternative individualized strategy for LV lead placement, without the need for pre-implant imaging, targeting the region with .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. latest electrical activation needs prospective evaluation.6