Left Ventricular Septum Pacing in Patients by Transvenous Approach Through the Inter-ventricular Septum
Condition: Left Ventricular Dysfunction; Cardiac Conduction Defect; Heart Failure; Sick Sinus Syndrome
MeSH terms: Heart Failure; Ventricular Dysfunction; Ventricular Dysfunction, Left; Sick Sinus Syndrome; Cardiac Conduction System Disease
Study type: Observational

Summary: 
      Cardiac pacing is the only effective treatment for symptomatic bradycardia. The right
      ventricular apex (RVA) has become the most frequently used ventricular pacing site. However,
      RVA pacing has been shown to cause left ventricular (LV) dyssynchrony wich can lead to LV
      dysfunction and development of heart failure. Recent studies in animals have demonstrated
      that pacing at the LV septum induces significantly less ventricular dyssynchrony than RVA
      pacing and is able to improve LV function to a similar degree as biventricular (BiV) pacing.
      In addition it was shown that a LV septum lead can be placed permanently by driving a lead
      with extended helix from the RV side through the inter-ventricular septum into the LV
      endocardial layer. This was shown to be a feasible and safe procedure and lead stability was
      shown during four months of follow-up in otherwise healthy and active canines. LV septum
      pacing may therefore be a good treatment alternative in patients with symptomatic
      bradycardia, as well as patients with an indication for cardiac resynchronization therapy
      (CRT). The purpose of this study is to translate the findings from preclinical studies to the
      clinical situation by investigating the feasibility, long-term lead stability and safety of
      LV septum pacing by transvenous approach through the inter-ventricular septum in patients.
    

Detailed description: 
      Cardiac pacing is the only effective treatment for symptomatic bradycardia. After the
      introduction of the implantable pacemaker (PM), the right ventricular apex (RVA) has become
      the most frequently used ventricular pacing site. However, clinical studies have shown that
      RVA pacing leads to left ventricular (LV) dyssynchrony, and on the long run to adverse
      structural changes (remodeling), a higher risk of developing atrial fibrillation and heart
      failure, and higher mortality.

      Recognition of the adverse effects of RVA pacing has generated interest in alternative
      ventricular pacing sites. Recent studies in animals have shown that pacing at the LV septum
      induces significantly less ventricular dyssynchrony than RVA pacing. In addition it was shown
      that a LV septum lead can be placed permanently by introducing a custom lead with extended
      helix transvenously and, after positioning it against the RV septum, driving it through the
      inter-ventricular septum into the LV endocardial layer. This was shown to be a feasible and
      safe procedure and lead stability was shown during four months of follow-up in otherwise
      healthy and active canines.

      Animal studies have also shown that LV septum pacing is able to improve LV function to a
      similar degree as simultaneous biventricular (BiV) pacing used in cardiac resynchronization
      therapy (CRT). CRT was introduced to restore the abnormal ventricular activation and
      contraction in patients with heart failure and intra-ventricular conduction delay. Large
      clinical trials have shown that CRT improves LV systolic pump function, reverses structural
      remodelling, improves quality of life and exercise tolerance, and decreases mortality.
      Unfortunately, problems encountered during positioning and fixation of the LV pacing lead in
      the coronary vein result in suboptimal or loss of CRT in at least a quarter of CRT candidates
      and require re-operation in 7% during follow up.

      The adverse effects of RVA pacing, the limitations of BiV pacing and the promising effects of
      LV septum pacing in preclinical studies have led to the idea that LV septum pacing may be a
      good treatment alternative in patients with symptomatic bradycardia, as well as patients with
      an indication for CRT. In the latter category, CRT could then be performed using a single
      ventricular pacing lead, thus limiting the number of lead implantations, and thereby reducing
      complication rate and implantation costs as well as avoiding the difficult access route
      through the coronary vein.

      It is the aim of this study to translate the findings from preclinical studies to the
      clinical situation by investigating the feasibility, long-term lead stability and safety of
      LV septum pacing by transvenous approach through the inter-ventricular septum in patients
      with a PM or CRT indication. The results may have a large impact on future pacing therapy.
      The LV septum may become the universal pacing site, being preferred for anti-bradycardia
      therapy, and being an equal alternative for BiV pacing, but easier to apply, less invasive
      and more cost-effective.
    

Intervention name(s): Left ventricular septum pacing lead
Intervention type(s): Device
Intervention description(s): A left ventricular septum pacing lead is permanently placed by introducing a custom lead with extended helix transvenously and, after positioning it against the RV septum, driving it through the inter-ventricular septum into the LV endocardial layer.
Other intervention name(s): Adapted Medtronic Select Secure 3830 pacing lead
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Study subjects are recruited from patients referred to the out-patient pacemaker/ICD clinic
        of our hospital.
      
Keywords: Cardiac pacing; Left ventricular septal pacing; Feasibility and safety; Lead stability; Hemodynamics; Left ventricular dyssynchrony; Pacing for heart failure; Cardiac resynchronization therapy