Canadian Journal of Cardiology

Mid-Depth-Septal Pacing Optimized Cardiac Resynchronization Therapy: A Novel Strategy

Published:April 14, 2022DOI:
      A 68-year-old man had had heart failure (HF) with dilated cardiomyopathy for 7 years. He had CRT indications including LV ejection fraction (LVEF) 28%, left bundle branch block (LBBB) with QRS duration 203 ms (Fig. 1A), and New York Heart Association (NYHA) functional class III. He received conventional CRT by right ventricular (RV) apical pacing (RVAP) and CVP in 2015 (Fig. 2B and B1). The QRS duration was shortened to 142 ms (Fig. 2B), and LVEF increased to 30%. However, the patient still experienced recurrent HF-related hospitalizations before he was admitted for elective replacement indicator in September 2021.
      Figure thumbnail gr1
      Figure 1Left: Twelve-lead electrocardiograms with intracardiac electrograms during baseline rhythm (A), right ventricular septal pacing (RVSP) (B), and mid-depth-septal pacing (MSP) (C). Right: Cardiac X-ray image with contrast agent for illustrating the depth (approximately 7 mm) of 3830 lead inside the septum (A1) and schematic possible propagating pattern of RVSP (B1) and MSP (C1). Green area represents right ventricular wall. Pink area represents left ventricular wall. LVAT, left ventricular activation time.
      Figure thumbnail gr2
      Figure 2Left: Twelve-lead electrocardiograms during conventional cardiac resynchronization therapy (CRT) (A, B) and MOT-CRT (C). Right: Schematic possible propagating patterns of conventional CRT (A1, B1) and MOT-CRT (C1). Green area represents right ventricular wall. Pink area represents left ventricular wall activated by RVSP (A1) or RVAP (B1) or MSP (C1) during different CRT. Yellow area represents left ventricular wall activated by coronary venous pacing. MOT-CRT, mid-depth-septal pacing optimized cardiac resynchronization therapy; MSP, mid-depth-septal pacing; RVAP, right ventricular apical pacing; RVSP, right ventricular septal pacing.
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Canadian Journal of Cardiology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Boettler P.
        • Claus P.
        • Herbots L.
        • et al.
        New aspects of the ventricular septum and its function: an echocardiographic study.
        Heart. 2005; 91: 1343-1348
        • Vijayaraman P.
        Left bundle branch pacing optimized cardiac resynchronization therapy: a novel approach.
        JACC Clin Electrophysiol. 2021; 7: 1076-1078
        • Strik M.
        • van Deursen C.J.
        • van Middendorp L.B.
        • et al.
        Transseptal conduction as an important determinant for cardiac resynchronization therapy, as revealed by extensive electrical mapping in the dyssynchronous canine heart.
        Circ Arrhythm Electrophysiol. 2013; 6: 682-689