Cardiac Resynchronisation Therapy In Patients With Heart Failure: Mechanistic Insights From Cardiac MRI And Electroanatomical Mapping

Study Overview
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Brief Summary
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Cardiac Resynchronisation Therapy (CRT) is a specialist pacemaker procedure that aims to improve the efficiency of the heartbeat. This treatment is used routinely in patients with heart failure and a delay in electrical conduction across the heart seen on the surface ECG (heart tracing). The investigators aim to assess acute response to CRT and compare different methods of delivering CRT using hemodynamic data from invasive dP/dTmax and electroanatomical data from either invasive mapping or non-invasive body surface mapping.

Official Title
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Cardiac Resynchronisation Therapy In Patients With Heart Failure: Mechanistic Insights From Cardiac MRI And Electroanatomical Mapping

Conditions
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Heart Failure

Intervention / Treatment
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* Procedure: Temporary pacing Study
* Radiation: Thoracic CT
* Diagnostic Test: Acute hemodynamic study
* Diagnostic Test: Non-invasive body surface mapping
* Diagnostic Test: Invasive catheter-based mapping


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participant is willing and able to give informed consent for participation in the study. Male or Female, aged 18 years or above. Either 1) has CRT system in situ or 2) has a planned CRT system implant or 3) has a planned upgrade to CRT from a standard pacemaker NYHA grade II-IV heart failure LVEF<35% Intrinsic QRS duration >120ms On optimum medical therapy for heart failure Female participants of child bearing potential must be willing to ensure that they or their partner use effective contraception during the study and for 3 months thereafter Able (in the Investigators opinion) and willing to comply with all study requirements. Willing to allow his or her General Practitioner and consultant, if appropriate, to be notified of participation in the study. Exclusion Criteria: Female participants who is pregnant, lactating or planning pregnancy during the course of the study. Scheduled elective surgery or other procedures requiring general anaesthesia during the study. Participant who is terminally ill or is inappropriate for placebo medication Any other significant disease or disorder which, in the opinion of the Investigator, may either put the participants at risk because of participation in the study, or may influence the result of the study, or the participant's ability to participate in the study. Rate uncontrolled atrial fibrillation precluding a cMR Significant peripheral vascular disease precluding an EP study A contraindication to anticoagulation A prosthetic aortic or tricuspid valve Significant Aortic valve disease Known LV thrombus Insufficient capacity to consent to the study

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: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Body surface mapping and temporary pacing<br>Temporary pacing procedure with acute hemodynamic study and non-invasive body surface mapping. | Procedure: Temporary pacing Study<br>* Temporary delivery of CRT<br>* Other names: Electrophysiology study;Radiation: Thoracic CT<br>* As part of non-invasive mapping protocol<br>Diagnostic Test: Acute hemodynamic study<br>* Measurement of invasive dP/dTmax<br>Diagnostic Test: Non-invasive body surface mapping<br>* Cardioinsight body surface mapping<br>|
| Experimental: Catheter-based mapping and temporary pacing<br>Temporary pacing procedure with acute hemodynamic study and invasive catheter-based mapping. | Procedure: Temporary pacing Study<br>* Temporary delivery of CRT<br>* Other names: Electrophysiology study;Diagnostic Test: Acute hemodynamic study<br>* Measurement of invasive dP/dTmax<br>Diagnostic Test: Invasive catheter-based mapping<br>* Invasive electroanatomical mapping<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Improvement in LV dP/dTmax >10 percent during temporary multisite pacing |  | Intra-procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Electrical dyssynchrony measured from electro-anatomical mapping |  | Intra-procedure |