Discussion
CRT relieves symptoms and decreases mortality in patients with heart failure, depressed LV systolic function, and prolonged QRS duration.5,6 To obtain maximum benefit from CRT, it is important to place the LV lead in a suitable region, particularly in lateral and non-apical positions, with a low pacing capture threshold, and without phrenic nerve stimulation. However, lead revision is required due to lead stability issues, such as incorrect pacing location, lead dislodgement, increase in pacing capture threshold, or phrenic nerve stimulation in up to 7% of CRT implantations.7 To overcome these, active fixation LV leads have been developed.8 The Medtronic Attain Stability Quad lead, which combines an active fixation mechanism with a quadripolar lead, allows for a targeted approach to LV pacing.3,9,10 Using an active fixation lead allows for better stability in veins, which often have large diameters, compared with a passive fixation lead, the stability of which concerns operators.11
It is also important to develop a technique to advance an LV lead through target vessels and to overcome lead stability issues. In clinical practice, it is sometimes difficult to advance an LV lead through narrow and tortuous vessels. In these cases, we use a subselection catheter, extra support guidewire, and an LV lead with minimum French size lead body diameter; however, these devices are sometimes ineffective. In such difficult cases, percutaneous coronary intervention techniques can be useful. For instance, in percutaneous coronary intervention, deep engagement of the guiding catheter could provide good support. Fujita et al. reported the use of the anchor method, in which deep engagement of the guiding catheter was achieved by pulling an anchor balloon inflated in a nontarget vessel. Using this method, superior guiding catheter support was maintained even after balloon deflation.4 And Kumagai et al. has reported the balloon anchor method for CRT implantation. 12 We applied this technique in LV lead implantation without using balloon catheter Temporary fixing of the lead was performed anterior to the target position. Pulling the fixed lead made the cannulation catheter advance further. This method provided superior cannulation catheter support without the LV lead falling out. Adjusting the cannulation catheter position could help the lead to advance further. It should be noted that pulling the lead too hard could cause the fixation helix to stretch. To avoid this, it was important to pull the lead as gently as possible. Moreover, if advancing the cannulation catheter was found to be too difficult, it should not be forced.
To our knowledge, this is the first study that reports the application of the anchor technique for LV lead implantation using the Medtronic Attain Stability Quad lead. The ‘lead anchor’ technique may help in the management of difficult cases of LV lead implantation. This novel technique could help the operators to efficiently advance LV leads through tortuous vessels during the CRT procedure.