Novel ICD Arrhythmia Detection Algorithm

Study Overview
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Brief Summary
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Implantable cardioverter defibrillators (ICD) are used to treat life-threatening heart rhythm disturbances (arrhythmias). They have been proven to reduce the risk of sudden cardiac death; however, there are limitations with current ICDs. Firstly, they may deliver inappropriate therapies (therapies delivered in the absence of life-threatening arrhythmias). Secondly, slower life-threatening arrhythmias may be left untreated because current programming recommendations, designed to minimise inappropriate therapies, rely predominantly on heart rates. Therefore, there is considerable potential to make ICDs safer with more sophisticated ICD algorithms. In this research study the investigators will collect data from participants with newly implanted or existing ICDs whilst they are in induced or spontaneously occurring abnormal rhythms. The data will come from sensors placed on the skin that can measure blood flow or electrical properties of the body. In addition, in 20 participants, the investigators will also collect further data from a small loop recorder implanted under the skin. The investigators will use this data to help develop and validate new methods of reliably identifying life-threatening arrhythmias so that future ICDs deliver therapies when only needed. The research is funded by the British Heart Foundation, and will take place at Hammersmith Hospital over 3 years. The investigators aim to recruit 100 patients in total.

Detailed Description
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This novel arrhythmia detection algorithm will incorporate a haemodynamic sensor and extra bipolar electrogram with an aim to outperform current commercially used arrhythmia detection algorithms that rely primarily on heart rate.

Official Title
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Improving Implantable Cardioverter-defibrillator Arrhythmia Detection: Development of a Novel Arrhythmia Detection Algorithm

Conditions
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ICD, Implantable Defibrillator User, Cardiomyopathies

Intervention / Treatment
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* Other: Observational Study during Clinical and Simulated arrhythmias in patients with ICDs


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Study A and B Patients referred for conventional defibrillator implantation or generator change. Adults (age > 18 years) Willing to take part and able to give consent. Study C Patients with defibrillators who are undergoing a VT ablation. Adults (age > 18 years) Willing to take part and able to give consent. Study D Patients with defibrillators already implanted who are able to exercise and raise their heart rate substantially Adults (age > 18 years) Willing to take part and able to give consent. Study E Patients with a defibrillator already implanted admitted with atrial arrhythmias, ventricular tachycardia or RV lead fracture. Adults (age > 18 years) Willing to take part and able to give consent. Exclusion Criteria: Exclusion criteria for studies A-E: Unable to give consent. Children (age < 18 years) Pregnant women. Exclusion criteria for studies A and B if undergoing VF induction: Intracardiac thrombus AF without regular anticoagulation Severe aortic stenosis Severe ischaemic heart disease Decompensated heart failure Exclusion criteria for study D Recent heart attack or stroke (within the last month) Thromboembolic event undergoing active treatment Severe aortic stenosis Severe ischaemic heart disease Hypertrophic obstructive cardiomyopathy Uncontrolled ventricular arrhythmias Physically unable to exercise, for example due to arthritis.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Simulated Arrhythmias<br>Simulate ventricular and/or atrial tachycardia via VVI or AAI pacing an ICD with an implantable loop recorder implant (or a surface bipolar electrogram) and haemodynamics. | Other: Observational Study during Clinical and Simulated arrhythmias in patients with ICDs<br>* Observational Study during Clinical and Simulated arrhythmias in patients with ICDs<br>|
| Clinical Arrhythmias<br>Genuine clinical VT (acute presentation), RV lead fracture/noise or sinus tachycardia on exercise whilst recording haemodynamics and a surface bipolar electrogram. | Other: Observational Study during Clinical and Simulated arrhythmias in patients with ICDs<br>* Observational Study during Clinical and Simulated arrhythmias in patients with ICDs<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Outperforming current arrhythmia detection algorithms | Improvement in sensitivity and specificity in accurately detecting ventricular arrhythmias in comparison to current algorithms. sensor and a separate electrical signal can out-perform current implantable cardioverter defibrillator algorithms. We will run different simulated and genuine arrhythmias through our novel detection algorithm and compare it against detection algorithms from all the major manufacturers with devices programmed as per HRS primary prevention guidelines. | 3 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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algorithm, haemodynamic sensor, bipolar electrogram, ICD, arrhythmia