Electrical Resynchronization and Acute Hemodynamic Effects of Direct His Bundle Pacing Compared to Biventricular Pacing

Study Overview
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Brief Summary
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The aims are to compare Direct His Bundle Pacing (DHBP) with biventricular pacing (BiV) in terms of electrical resynchronization using electrocardiographic imaging (ECGI) and also in terms of acute hemodynamical effect using finger plethysmography and conduction velocimetry. The study will be a randomized crossover design with acute measurements.

Detailed Description
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By recruiting native conducting tissue to relay electrical activation of the ventricles via the Purkinje fibre network, DHBP may potentially achieve greater electrical resynchronization and hemodynamic benefit compared to BiV where the electrical activation wavefronts propagate from two discrete pacing sites. Electrical synchrony achieved by these pacing modes have however never been compared. Furthermore, the acute hemodynamic effect of DHBP has been compared to BiV only in a small single study to date. The aims are to compare DHBP with BiV in terms of electrical resynchronization using electrocardiographic imaging (ECGI) and also in terms of acute hemodynamical effect using finger plethysmography and conduction velocimetry. The primary endpoint will be left ventricular activation time, with secondary endpoints including various electrical (right ventricular activation time, total ventricular activation time etc) and hemodynamic parameters (systolic pressure, cardiac output, cardiac contractility). It is expected that DHBP offers shorter left ventricular activation time (i.e. better synchrony) and hemodynamic benefit compared to BiV.

Official Title
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Electrical Resynchronization and Acute Hemodynamic Effects of Direct His Bundle Pacing Compared to Biventricular Pacing

Conditions
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Cardiac Pacing, Artificial, Cardiac Resynchronization Therapy, Direct His Bundle Pacing

Intervention / Treatment
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* Device: Pacing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Treatment of heart failure with a standard indication for CRT (NYHA III-IV, LVEF < 35% and QRS > 130ms; or LVEF< 40% and requirement for frequent ventricular pacing, irrespective of baseline QRS duration) and optimal medical treatment. Permanent atrial fibrillation (allowing connection of the DHBP lead to the atrial port). Patients implanted with 1) a CRT pacemaker or CRT defibrillator 2) a His lead with selective or non-selective DHBP, connected to the atrial port of the generator 3) a functional right ventricular lead and 4) a functional coronary sinus lead. DHBP with selective or non-selective His capture Exclusion Criteria: Age <18 years Pregnancy Inability to undergo CT or an MRI (e.g. due to severe claustrophobia) Inability or refusal to sign the patient informed consent form.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Direct His Bundle Pacing<br>Pacing from the His bundle lead | Device: Pacing<br>* Programming of either Direct His Bundle pacing or biventricular pacing<br>|
| Active Comparator: Biventricular Pacing<br>Pacing from the right ventricular and coronary sinus leads | Device: Pacing<br>* Programming of either Direct His Bundle pacing or biventricular pacing<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Left ventricular activation time | Duration of left ventricular electrical activation | 5 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Right ventricular activation time | Duration of right ventricular electrical activation | 5 minutes | 
| Total ventricular activation time | Duration of total ventricular electrical activation | 5 minutes | 
| Systolic pressure | Systolic blood pressure measured by finger plethysmography | 5 minutes | 
| Cardiac output | Cardiac output measured by conductive velocimetry | 5 minutes | 
| Cardiac contractility | Cardiac contractilit measured by conductive velocimetry | 5 minutes |