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.