LV Endocardial Cardiac Resynchronisation Therapy

  • Research type

    Research Study

  • Full title

    A randomised double-blinded cross over study to evaluate the improvement of left ventricular systolic failure using targeted left ventricular endocardial lead placement in cardiac resynchronisation therapy. (Endo-CRT)



  • Contact name

    Tom Wong

  • Contact email

  • Sponsor organisation

    Royal Brompton and Harefield NHS Foundation Trust

  • Research summary

    In some types of heart failure, a biventricular pacemaker can help the heart beat more efficiently. With these pacemakers, three electrical leads are placed in the heart: one in the right atrium (upper chamber) and one each in the right and left ventricle (lower chambers). The leads send electrical signals from the pacemaker to the walls of the heart to re-coordinate the timing of their contraction. This technique is called cardiac resynchronisation therapy (CRT), and can improve patients’ symptoms, morbidity, mortality, and reduce hospitalisation. Unfortunately, a significant proportion of patients do not respond to CRT, even though by conventional criteria they should, or CRT is technically unsuccessful, meaning left ventricular lead placement has been unsuccessful.

    In conventional CRT, an epicardial left ventricular (LV) lead goes through a vein on the outside of the heart. In contrast, CRT using an endocardial LV lead targets the lead placement inside the LV. We aim to show that targeted left ventricular endocardial lead placement improves LV function in patients who have limited response or technical failure with conventional epicardial LV lead placement. We will investigate the improvement of different aspects of heart failure including: oxygen consumption, exercise testing, symptoms, echocardiographic indices, non-invasive cardiac output measurement and biochemical markers. We will also investigate the correlation between echocardiographic, myocardial perfusion and voltage mapping for both scar location and site of latest electrical or mechanical activation. This may help predict the optimum LV lead implantation site prior to the procedure.

    While CRT with endocardial LV lead has been used when clinically appropriate, the technique has yet to be prospectively assessed. This trial could potentially inform a larger study with targeted selection for endocardial lead placement in patients in who are not likely to improve with conventional lead placement due to underlying venous anatomy or scar distribution.

  • REC name

    London - Bromley Research Ethics Committee

  • REC reference


  • Date of REC Opinion

    30 Apr 2014

  • REC opinion

    Further Information Favourable Opinion

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