Study patients
This study consisted of 74 consecutive patients who underwent de novo
CRT implantation between January 2015 and July 2019. In addition, 8
patients with CRT upgrades from pacemaker or implantable cardioverter
defibrillation (ICD) systems, which were guided by Inner-Cath only, were
investigated. All patients received de novo CRT implantation or
upgrade to CRT systems according to guideline indications (17) that
included patients with NYHA classes II-III or IV despite optimal medical
treatment, LV ejection fraction (LVEF) ≦ 35% and QRS duration ≧120ms,
or LVEF <50% and expected high frequency right ventricular
(RV) pacing. The patients with de novo CRT implantation were divided
into two groups based on the type of guiding catheter used initially for
LV lead placement (LV-LP), namely, 7Fr Inner-Cath (Inner-Cath group,
N=42) and 9 or 10Fr Outer-Cath (Outer-Cath group, N=32). Outer-cath was
selected as a first-line method in the first 32 patients. Inner-cath was
selected as a first-line method in the latter 42 patients. This study
was a non-randomized retrospective observational study. The research
protocol had been approved by the local Research Ethics Committee.
Informed consent was obtained in the form of opt-out.