An observational study in Inherited Cardiac Arrhythmias, Long QT Syndrome and Arrhythmogenic Right Ventricular Cardiomyopathy, sponsored by University of British Columbia. Completed at 1 site in Canada. Open to participants aged 2 Years and older. Per ClinicalTrials.gov, last updated 2020-11-16.
Sponsored by University of British Columbia · Observational
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Risk prediction in in inherited heart rhythm conditions that may cause sudden cardiac arrest or death is difficult. Sometimes the risks may be low but the loss of life in an otherwise healthy young individual is catastrophic. Clinicians often treat to the extreme to prevent this and so often those at unknown risk for a serious cardiac event are treated with an implanted cardioverter defibrillator (ICD) to protect against sudden death even though the risk is low or unknown. ICDs them selves are not without adverse events such as needing battery replacements, mechanical complications, inappropriate shocks and body image and self esteem issues for the patient. This study will use an inject able monitor that is less invasive to monitor inherited heart rhythm patients long term to help gather long term heart rhythm data (3 years) on patients with an inherited heart rhythm that will help to detect symptoms of dangerous heart rhythms so that the appropriate care can be provided.
Risk stratification is challenging in latent genetically mediated sudden death syndromes, where the absolute risks are low but the loss of life is catastrophic in otherwise well young individuals. Countering this is the manifest drawbacks of liberal use of Implantable Cardioverter Defibrillator (ICDs) in this population, who may suffer harm from the limitations of ICDs with respect to repeated generator changes, lead/mechanical complications, non-target shocks and issues with body image and self esteem. This balance is struck with patients and clinicians in the inherited arrhythmia clinics daily.
The Principal Investigator has a longstanding interest in cardiac monitoring and syncope, with extensive experience with cardiac monitoring technologies. Recently published data from the study team indicates that 69% of unexplained cardiac arrest patients had suffered syncope, presyncope, chest pain or palpitations, significantly greater than the 43% incidence in their first-degree relatives8. The prevalence of syncope was 34% in those patients with subsequently diagnosed inherited causes of cardiac arrest. This suggests an excellent opportunity to detect symptomatic and asymptomatic arrhythmias in patients to risk stratify patients and direct ICD resources to patients that are likely to benefit. Coupling of recording with remote monitoring of device-detected events enables a short time from detected arrhythmia to reporting and resultant clinical decision-making (base station in the patient's home transmits any acquired data daily).
An intermediate risk population is seen regularly in the inherited arrhythmia clinic, based on a wide array of clinical features that are proven or suspected risk markers in patients who either prefer to avoid an ICD, or whose risk is insufficient to clearly warrant an ICD. The risk in these individuals is hampered by the relatively uncommon short-term risk of spontaneous arrhythmia that is detected by routine 24-48 Holter surveillance to assist as a "tie breaker", to favor more aggressive therapy with an ICD. This study will extend the monitoring period of intermediate risk patients to 3 years and enable detection of symptomatic and asymptomatic ventricular arrhythmia that would inform risk discussion with the patient and favor more aggressive therapy. The latter may involve incremental drug therapy, cardiac sympathectomy or an ICD.
Loop recorder implantation (Reveal LINQ, Medtronic, Minneapolis MN), also called an insertable cardiac monitor (ICM) has the ability to analyze the beat to beat variability of cardiac cycles on a 2 minute ECG strip and stores the tracing for visual confirmation of any cardiac events. The device also provides the patient with the ability to activate the device manually and so facilitates analysis of heart rhythm during symptomatic events.
The device is manufactured and will be provided by Medtronic Canada Ltd, 99 Hereford Street, Brampton, Ontario L6Y 0R3 +1 905-460-3800. The Medtronic Reveal LINQ is a programmable device that continuously monitors a patient's ECG and other physiological parameters. The device records cardiac information in response to automatically detected arrhythmias and patient activation. The form factor of the device has changed from that similar to a USB thumb drive that requires surgical implantation to that of a paper clip that can be injected in a minimally invasive environment including office based clean rooms. This device is small leadless and is inserted under the skin, in the chest. The device can be inserted by the physician in the office, saving precious healthcare resources.
Potential Adverse Events include but are not limited to:
101 studies on the registry are indexed under Long QT Syndrome; 20 are open to participants now.
This study's enrollment of 1,051 is above the median of 150 across 53 observational studies indexed under Long QT Syndrome.
Browse Long QT Syndrome studies →University of British Columbia is the lead sponsor of 1,340 studies on the registry; 260 are open to participants now.
Of its 6 completed or terminated interventional studies of FDA-regulated products, 1 (17%) have results posted.
Counted across the registry records on this site, refreshed daily.
Risk stratification is challenging in latent genetically mediated sudden death syndromes, where the absolute risks are low but the loss of life is catastrophic in otherwise well young individuals. Countering this is the manifest drawbacks of liberal use of Implantable Cardioverter Defibrillator (ICDs) in this population, who may suffer harm from the limitations of ICDs with respect to repeated generator changes, lead/mechanical complications, non-target shocks and issues with body image and self esteem. This balance is struck with patients and clinicians in the inherited arrhythmia clinics daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Inherited Heart Rhythm (IHR) patient with breakthrough symptoms on best medical care that does not warrant an ICD, or patient declines ICD:
Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) with at least 2 minor or 1 major 2010 task force criteria,
Asymptomatic IHR patient with extreme phenotype, does not warrant an ICD
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Detection of ≥5 beats of non-sustained wide QRS complex tachycardia (i.e. likely to be VT).
The number of irregular heart rates requiring change in treatment
Time frame: From time of implant to time of cardiac event requiring intervention (maximum 3 years)
Time to diagnosis
Time to determine risk and required intervention
Time frame: From time of implant to time of recorded finding indicating a diagnosis (maximum 3 years)
ICD implant rate
How many participants will require treatment with an implanted cardioverter defibrillator
Time frame: From time of implant to time of preventative treatment (maximum 3 years)
Mortality
In the event of a death the cause will be classified by the site investigator as cardiac, non cardiac, sudden and non sudden
Time frame: Time of implant until date of death (maximum 3 years)
ICM Complication rate
Number of problems related to the device, infection, pain, premature removal
Time frame: Time of implant to time of treatment for complication (maximum 3 years)
Plan to share: No
No publications or documents are linked to this record.
Ran from May 2015 to primary completion in Aug 2020, 63 months.
Of 21 observational studies under Long QT Syndrome, half reached primary completion within 56 months of starting (the median), counting those still running; a quarter within 26 and three quarters within 81. This study's 63 months is above that.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Nov 2020. You cannot join it, but the record below documents what was studied.
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University of British Columbia →