CRT In Narrow QRS 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). Also CRT has been seen to improve some heart failure patients with a normal electrical conduction (seen on the ECG as a narrow QRS complex). The investigators aim to see if cardiac MRI can be used to select patients with normal electrical conduction for CRT, therefore expanding the number of people who would stand to benefit from this treatment.

Official Title
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Cardiac Resynchronisation Therapy In Patients With Narrow QRS Morphology And 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: Body Surface 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. NYHA grade III-IV heart failure LVEF<35% 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. Contraindication to an MRI scan 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: Diagnostic
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Mechanical Dyssynchrony<br>Those with cardiac MRI evidence of mechanical dyssynchrony | Procedure: Temporary pacing study<br> <br> * Other names: Electrophysiological study;Radiation: Body Surface Mapping<br> <br> * Other names: ECG imaging;|
| Active Comparator: No Mechanical Dyssynchrony<br>Those without mechanical dyssynchrony on cardiac MRI | Procedure: Temporary pacing study<br> <br> * Other names: Electrophysiological study;Radiation: Body Surface Mapping<br> <br> * Other names: ECG imaging;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| LV dP/dT during pacing | To assess LV dP/dT during different pacing modalities by intraventricular pressure wire. A dP/dT change of >10% from baseline is a positive result. | during temporary pacing study, approximately 2 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of electrical and mechanical dyssynchrony | To correlate the amount of mechanical dyssynchrony seen prior to pacing with electrical dyssynchrony measures from non-contact mapping and body surface mapping | Data is collected prior to temporary pacing study, the post processing needed in order to correlate this data may take up to 2 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Heart Failure, Pacing, Resynchronization, Electrophysiology, Imaging, Cardiac Resynchronization Therapy