Management
Despite guideline-directed medical therapy his heart failure symptoms
persisted. Considering the LV impairment and dyssynchronous ventricular
activation, he was offered a device upgrade to a CRT-P with either a
conventional LV lead or a His bundle lead, in addition to an RA lead to
improve VV and AV synchrony, respectively. Prior to implantation left
sided venography was performed to evaluate vein patency which showed an
occluded subclavian vein (Figure 1). Options considered included: 1) a
contralateral CRT-P implantation; 2) implanting a right sided RA and LV
lead and tunneling across to the left; 3) venoplasty facilitated
CRT-upgrade; 4) lead extraction of the functional RV lead for
re-canalisation and upgrade; 5) a conservative approach. After careful
discussion, the patient elected to proceed with an upgrade strategy
(including venoplasty and lead extraction).
As a centre with experience in His Bundle pacing (HBP), and in alignment
with recent AHA/ACC guidelines (1), we targeted CRT-P via this approach.
The least aggressive strategy was preferable and therefore prior to
opening the left-sided pocket, the SCV occlusion was probed in a
retrograde manner using a multipurpose catheter (6F MPA1 Impulse, Boston
Scientific, Mass) from right femoral venous access (secured for
temporary pacing wire support). In doing so, we were able to direct the
catheter to the brachio-cephalic vein and define the occlusion in
detail. Furthermore, contrast highlighted a large collateral branch,
which we felt could be punctured directly from a left sub-clavicular
approach (Figure 1). We left a 0.035in J wire in this branch, and
successfully secured venous access through the Seldinger technique
(Figure 2, Video 1). A passive lead to the right atrial appendage was
implanted and a 69cm Select Secure 3830 lead (Medtronic Inc, MN) was
deployed via a C315 sheath (Medtronic) at the His bundle.
Intracardiac electrograms confirmed underlying complete AV dissociation
with an intrinsic His-QRSend interval of 192ms. With
HBP, non-selective capture was achieved resulting in a shortened
Stim-QRSend of 158ms with a threshold of 1V at 0.5ms
(Figure 3). The device was programmed DDD-60 with an “LV” to RV delay
of 60ms, to allow protective back up RV pacing in the event of loss of
His capture. There were no complications and post procedural 12-lead ECG
confirmed non-selective His capture.