Ventricular TachycardiaVT flowNCT05841199
Coronary Flow During Rapid Heart Rates
An observational study of Ventricular Tachycardia and Coronary Artery Disease, run by Imperial College London at 1 site in United Kingdom.
Trial summary
The goal of this observational study is to learn about the factors which determine how well ventricular tachycardia (VT) is tolerated. The main questions it aims to answer are: 1. What impact does coronary artery disease have on the ability for a patient to tolerate VT? 2. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Ventricular Tachycardia, Coronary Artery Disease, Heart Failure
- What is being tested?
- Pressure and flow measurement during simulated VT
- How many people
- 70 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 1 Aug 2023to 2 Jun 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adults referred for coronary angiography or coronary angioplasty.
Who may be able to join
- Able to give valid consent
- Referred for coronary angiography or coronary angioplasty
- Suitable for percutaneous physiological interrogation and PCI when clinically indicated
Who cannot join
- Unable to give valid consent
- Pregnant or breastfeeding women
- Unstable coronary artery disease (acute coronary syndrome)
- Severe multivessel coronary artery disease suitable for coronary artery bypass grafting
- Severe heart valve disease
- Severe (NYHA IV) heart failure
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site, 1 recruiting
- Recruiting
Imperial College NHS Foundation Trust
London, W12 0HS
Rahul Bahl, 020 7594 5735, r.bahl@imperial.ac.uk
Ricardo Petraco, 020 7594 5735, r.petraco@imperial.ac.uk
About this study
Official title: Coronary Epicardial and Microcirculatory Determinants of Ventricular Tachycardia Tolerability
The goal of this observational study is to learn about the factors which determine how well ventricular tachycardia (VT) is tolerated. The main questions it aims to answer are:
- What impact does coronary artery disease have on the ability for a patient to tolerate VT?
- Does treatment of coronary artery disease with stents improve the tolerability of VT?
Participants who are undergoing a clinically indicated coronary angiogram or coronary angioplasty procedure will have measurements of blood pressure, coronary pressure and coronary flow made during pacing at a range of heart rates.
Read the detailed description
Ventricular tachycardia (VT) is a common and life-threatening arrhythmia that occurs in people with heart problems. Some patients who develop this arrhythmia remain very stable with very little symptoms while others become unstable with low blood pressure or even sudden death. It is not known why some people tolerate the arrhythmia well and others do not.
If VT is not tolerated then current practice is to offer an implantable cardioverter defibrillator (ICD) which can deliver a shock to the heart if dangerous heart rhythms are detected. While shocks can be life-saving, they are also harmful, including causing psychological distress. ICDs also frequently deliver shocks when they are not needed.
If research could identify which factors predispose a person to be stable or unstable in VT, this would allow doctors to help them in a range of ways. One way would be to treat patients to improve the tolerance of VT, so avoiding the need for an ICD. Another would be to assess the the risk of instability and so allow a patient-centred decision on whether an ICD is needed.
In this study the investigators plan to recruit patients who are referred for a coronary angiogram. During the angiogram, the investigators will stimulate the heart at a range of fast heart rates and measure their blood pressure and flow in their coronary arteries. In patients who undergo stenting for a coronary stenosis, the investigators will also make these measurements after stenting so they can see if there is any difference. By recruiting a range of different cardiology patients, the investigators will be able to assess which factors contribute to stability during VT.
- Conditions
- Ventricular Tachycardia, Coronary Artery Disease, Heart Failure, Coronary Microvascular Dysfunction, Coronary Microvascular Disease
- Being tested
- Pressure and flow measurement during simulated VT
- Keywords
- Ventricular Tachycardia, Coronary Artery Disease, Heart Failure, Coronary Microvascular Dysfunction, Coronary Microvascular Disease, Percutaneous Coronary Intervention, Implantable Cardioverter Defibrillator
- Medical subject headings
- Tachycardia, Ventricular, Coronary Artery Disease, Heart Failure, Microvascular Angina
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Pressure and flow measurement during simulated VTDiagnostic test
Participants undergoing coronary angiography will have measurements of blood pressure, coronary pressure and coronary flow during simulated VT. VT will be simulated using pacing at a range of heart rates.
| Study group | Role | What they receive |
|---|---|---|
| Controls | 10 patients with unobstructed coronary arteries, normal microvascular function and normal LV function. Receives: Diagnostic Test: Pressure and flow measurement during simulated VT | |
| Coronary artery disease | 25 patients with severe, single-vessel coronary artery disease of the proximal LAD or proximal other dominant vessel awaiting PCI. Receives: Diagnostic Test: Pressure and flow measurement during simulated VT | |
| Microvascular dysfunction | 15 patients with without severe disease in any coronary artery, impaired microvascular function and normal LV function. Receives: Diagnostic Test: Pressure and flow measurement during simulated VT | |
| Heart failure | 20 patients with LV systolic dysfunction (LVEF<40%). Receives: Diagnostic Test: Pressure and flow measurement during simulated VT |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in coronary flow in participants with different levels of coronary microvascular function.
Measured: At baseline and during simulated VT
Change in coronary flow in participants immediately before and after PCI
Measured: At baseline and during simulated VT, immediately before PCI and after PCI
Change in blood pressure in participants with different levels of coronary microvascular function.
Measured: At baseline and during simulated VT
Change in blood pressure in participants before and after PCI
Measured: At baseline and during simulated VT, immediately before PCI and after PCI
Secondary outcomes (2)
Change in coronary flow in participants with different levels of left ventricular function
Measured: At baseline and during simulated VT
Change in blood pressure in participants with different levels of left ventricular function
Measured: At baseline and during simulated VT
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 May 2023
- Study start1 Aug 2023
- Primary completion2 Jun 2026 (estimated)
- Study completion2 Jun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Ventricular TachycardiaStudies of the same condition, open and under way.
- More trials run by Imperial College LondonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 70 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Imperial College London
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Ricardo Petraco, Principal investigator, Senior Clinical Research Fellow
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05841199
- Sponsor's protocol ID
- 22HH7955
- Acronym
- VT flow
- Status last verified
- Mar 2026
- First submitted
- 23 Mar 2023
- Last updated
- 27 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 27 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Coronary Epicardial and Microcirculatory Determinants of Ventricular Tachycardia Tolerability
- ClinicalTrials.gov ID
- NCT05841199
- Acronym / sponsor ID
- VT flow / 22HH7955
- Conditions
- Ventricular Tachycardia, Coronary Artery Disease, Heart Failure, Coronary Microvascular Dysfunction, Coronary Microvascular Disease
- Keywords
- Ventricular Tachycardia, Coronary Artery Disease, Heart Failure, Coronary Microvascular Dysfunction, Coronary Microvascular Disease, Percutaneous Coronary Intervention, Implantable Cardioverter Defibrillator
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 70 participants (estimated)
- Lead sponsor
- Imperial College LondonUniversity, hospital or other
- Study start
- 1 Aug 2023 (actual)
- Primary completion
- 2 Jun 2026 (estimated)
- Study completion
- 2 Jun 2026 (estimated)
- First posted
- 3 May 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this observational study is to learn about the factors which determine how well ventricular tachycardia (VT) is tolerated. The main questions it aims to answer are:
- What impact does coronary artery disease have on the ability for a patient to tolerate VT?
- Does treatment of coronary artery disease with stents improve the tolerability of VT?
Participants who are undergoing a clinically indicated coronary angiogram or coronary angioplasty procedure will have measurements of blood pressure, coronary pressure and coronary flow made during pacing at a range of heart rates.
Detailed description
Ventricular tachycardia (VT) is a common and life-threatening arrhythmia that occurs in people with heart problems. Some patients who develop this arrhythmia remain very stable with very little symptoms while others become unstable with low blood pressure or even sudden death. It is not known why some people tolerate the arrhythmia well and others do not.
If VT is not tolerated then current practice is to offer an implantable cardioverter defibrillator (ICD) which can deliver a shock to the heart if dangerous heart rhythms are detected. While shocks can be life-saving, they are also harmful, including causing psychological distress. ICDs also frequently deliver shocks when they are not needed.
If research could identify which factors predispose a person to be stable or unstable in VT, this would allow doctors to help them in a range of ways. One way would be to treat patients to improve the tolerance of VT, so avoiding the need for an ICD. Another would be to assess the the risk of instability and so allow a patient-centred decision on whether an ICD is needed.
In this study the investigators plan to recruit patients who are referred for a coronary angiogram. During the angiogram, the investigators will stimulate the heart at a range of fast heart rates and measure their blood pressure and flow in their coronary arteries. In patients who undergo stenting for a coronary stenosis, the investigators will also make these measurements after stenting so they can see if there is any difference. By recruiting a range of different cardiology patients, the investigators will be able to assess which factors contribute to stability during VT.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Controls | – | Diagnostic Test: Pressure and flow measurement during simulated VT10 patients with unobstructed coronary arteries, normal microvascular function and normal LV function. |
| Coronary artery disease | – | Diagnostic Test: Pressure and flow measurement during simulated VT25 patients with severe, single-vessel coronary artery disease of the proximal LAD or proximal other dominant vessel awaiting PCI. |
| Microvascular dysfunction | – | Diagnostic Test: Pressure and flow measurement during simulated VT15 patients with without severe disease in any coronary artery, impaired microvascular function and normal LV function. |
| Heart failure | – | Diagnostic Test: Pressure and flow measurement during simulated VT20 patients with LV systolic dysfunction (LVEF<40%). |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adults referred for coronary angiography or coronary angioplasty.
Key inclusion criteria (3 listed)
- Able to give valid consent
- Referred for coronary angiography or coronary angioplasty
- Suitable for percutaneous physiological interrogation and PCI when clinically indicated
Key exclusion criteria (6 listed)
- Unable to give valid consent
- Pregnant or breastfeeding women
- Unstable coronary artery disease (acute coronary syndrome)
- Severe multivessel coronary artery disease suitable for coronary artery bypass grafting
- Severe heart valve disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Pressure and flow measurement during simulated VTParticipants undergoing coronary angiography will have measurements of blood pressure, coronary pressure and coronary flow during simulated VT. VT will be simulated using pacing at a range of heart rates. | Diagnostic test | Controls, Coronary artery disease, Heart failure, Microvascular dysfunction |
Primary outcome
Change in coronary flow in participants with different levels of coronary microvascular function.
Time frame: At baseline and during simulated VT
Change in coronary flow in participants immediately before and after PCI
Time frame: At baseline and during simulated VT, immediately before PCI and after PCI
Change in blood pressure in participants with different levels of coronary microvascular function.
Time frame: At baseline and during simulated VT
Change in blood pressure in participants before and after PCI
Time frame: At baseline and during simulated VT, immediately before PCI and after PCI
2 secondary outcomes
Change in coronary flow in participants with different levels of left ventricular function
Time frame: At baseline and during simulated VT
Change in blood pressure in participants with different levels of left ventricular function
Time frame: At baseline and during simulated VT
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Mar 2026.
- Individual participant dataSharing planned: Undecided
Related trials for Ventricular Tachycardia
Enrolling by invitation
VINTAGE (Ventricular Intramyocardial Navigation for Tachycardia Ablation Guided by Electrograms) Using Commercial Off-The-Shelf (COTS) Catheters
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RecruitingPhase 1
A Study of SGT-501 Gene Therapy in Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT)
Catecholaminergic Polymorphic Ventricular Tachycardia
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Safety and Effectiveness of the Sphere-9™ Catheter and Affera™ Ablation System for the Treatment of Ventricular Tachycardia (Sphere VT)
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Active, not recruiting
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SPIKE FLOW Endocardial Lead Safety and Performance Study
Acute Myocardial Infarction (AMI), Asystole
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Ricardo Petraco principal investigator
Senior Clinical Research Fellow
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Ventricular Tachycardia and Coronary Artery Disease, run by Imperial College London at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 27 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Rahul Bahl (+44 20 7594 1093, r.bahl@imperial.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in coronary flow in participants with different levels of coronary microvascular function. (time frame: At baseline and during simulated VT). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Mar 2026.