br Methods br Results br Discussion br Conclusion br

Methods
Results
Discussion
Conclusion
Conflict of interest
Introduction Placement of the left ventricular (LV) pacing lead in a tributary of the coronary sinus (CS) is one of the most challenging technical aspects of cardiac resynchronization therapy (CRT) device implantation. Failure to implant an LV lead during attempted CRT occurs in 5–15% of the cases [1,2]. This may be because of an inability to cannulate the CS ostium, inability to pass the LV lead into a CS branch, unsatisfactory pacing parameters, or phrenic nerve stimulation (PNS). Despite improvements in leads and lead delivery systems and increased operator experience, some lead implants remain difficult and technically challenging. We tested a novel technique based on the combined use of an Amplatz guiding catheter and Quick-Cross support catheter to create a progressively supportive rail to implant the LV lead.
Case report A 32-year-old male with non-ischaemic cardiomyopathy, left bundle-branch block (LBBB; QRS 160ms), an LV ejection fraction (LVEF) of 30%, and New York Heart Association (NYHA) class II symptoms was referred to our centre for a further attempt at an LV lead implant. Cannulation of the CS had proved difficult at the referring centre and the implanter had been unable to advance different guide catheters over the wire into the CS. A dual-chamber buy p-Chlorophenylalanine was left in situ. At our centre, a coronary angiogram was done to visualise the anatomy of the CS and to locate the ostium in the right and left anterior oblique views. A 6-Fr Decapolar Livewire steerable catheter (St. Jude) was advanced from the right femoral vein to locate the coronary sinus ostium. With these markers in place, the CS was successfully cannulated using a 6-Fr Amplatz coronary guiding catheter (AL2) and an exchange length 0.035in. straight-tip standard Terumo guide wire placed in the distal CS. Attempts to advance the delivery sheath into the CS resulted in buckling, prolapse of the guide wire, and repeated dislodgement of the sheath. Repeated attempts using a buddy wire failed to advance the delivery sheath into the distal CS (Fig. 1). A 135-cm support catheter (Model number 518-037, Spectranetics Quick-Cross) with a proximal shaft diameter of 4.8Fr tapering to a distal shaft diameter of 3.8Fr (Fig. 2) was advanced through the AL2 guided over the Terumo guide wire into the distal CS (Fig. 3). The Terumo guide wire was exchanged for a 0.035in. standard J-tip polytetrafluoroethylene (PTFE) guide wire while maintaining the support catheter in place. The proximal luer fitting of support catheter was cut and an inner sheath (Attain Select II) advanced over the support catheter into the distal portion of the CS (Fig. 4). After removal of the support catheter and the 0.035in. guide wire, a 0.014in. percutaneous transluminal coronary angioplasty (PTCA) wire (PT2, Boston Scientific) was advanced through the inner sheath into one of the lateral branches of the CS. A 4-Fr bipolar LV pacing lead (Attain Ability 4196-88, Medtronic) was advanced over the wire to the selected branch (Fig. 5). In view of the LV dysfunction and documented non-sustained ventricular tachycardia, the right ventricular pacing lead was extracted with gentle traction. A single coil defibrillation lead (Sprint Quattro Secure 6935) was placed at the right ventricular apex instead (Fig. 6). The patient tolerated the procedure well without any complications and was discharged from hospital the following day. The total fluoroscopy time was 25min.
Discussion Recognising the importance of guide support for LV lead delivery, implanting physicians are moving toward a more interventional approach. Various pre-shaped guide support based systems are available with different manufacturers [3]. In our patient, the use of a support catheter to serve as a rail for placement of the inner sheath deep into the CS facilitated implantation of the LV pacing lead. This technique is safe and easily applied.