Coronary Flow During Rapid Heart Rates
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Pressure and flow measurement during simulated VT.
- Who it may be relevant to
- Registry conditions: Ventricular Tachycardia, Coronary Artery Disease, Heart Failure, Coronary Microvascular Dysfunction. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United Kingdom
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
Coronary Epicardial and Microcirculatory Determinants of Ventricular Tachycardia Tolerability
Overview
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. 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.
Interventions
- Diagnostic test Pressure and flow measurement during simulated VT
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.
Primary outcome measures
- 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]
Secondary outcome measures (2)
- 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]
Eligibility criteria
Inclusion criteria
- Able to give valid consent
- Referred for coronary angiography or coronary angioplasty
- Suitable for percutaneous physiological interrogation and PCI when clinically indicated
Exclusion criteria
- 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
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
United Kingdom · 1 center
- Imperial College NHS Foundation Trust — London
Identifiers
NCT: NCT05841199 · 22HH7955