Genetic Analysis of Heart Channelopathies in Brazilian Patients and Their Relatives
Channelopathiesseveral genes have been associated with ion channel diseases, but a large number of families do not yet have an identified genetic cause. There is a lack of information on the genetic characteristics of channelopathies in Brazilians affected by these diseases. This study aims to carry out a comprehensive genetic analysis of cardiac channelopathies in Brazilian patients and their families. The study will involve 20 patients and 80 family members (a total of 100 individuals) accompanied by the Rede D'Or arrhythmia group in Rio de Janeiro. Individuals will be recruited and subjected to DNA sequencing and phenotypic evaluation, including clinical evaluation, echocardiography, 24-hour Holter or longer electrocardiographic monitoring. An integrated analysis of phenotype-genotype will be made in all individuals included in the study. Patients and their families will be followed up annually for 2 to 5 years through clinical evaluations and the same complementary methods described. The DNA sequencing of patients and their families may contribute to improve the diagnosis of channelopathies and allow the determination of the pattern of occurrence of the disease in the cases involved. Besides, this study may lead to the discovery of new genetic variants associated with channelopathies that will serve as a basis for designing and carrying out broader molecular epidemiological studies. The study of the molecular genetics of channelopathies is important mainly so that patients can avoid sudden death, but also for the medical community, researchers, laboratories, companies involved in the production of medical devices, and public health authorities
Rare Disease Patient Registry & Natural History Study - Coordination of Rare Diseases at Sanford...
Rare DisordersUndiagnosed Disorders316 moreCoRDS, or the Coordination of Rare Diseases at Sanford, is based at Sanford Research in Sioux Falls, South Dakota. It provides researchers with a centralized, international patient registry for all rare diseases. This program allows patients and researchers to connect as easily as possible to help advance treatments and cures for rare diseases. The CoRDS team works with patient advocacy groups, individuals and researchers to help in the advancement of research in over 7,000 rare diseases. The registry is free for patients to enroll and researchers to access. Visit sanfordresearch.org/CoRDS to enroll.
National Exhaustive Cohort of Hereditary Stomatocytoses and Other Channelopathies Affecting the...
StomatocytosisHereditary stomatocytosis is a heterogeneous group of rare constitutional diseases of dominant transmission in the vast majority of cases. The data concerning their clinical and biological presentation, and their evolution are few, and come from about thirty clinical cases. The constitution of an exhaustive French cohort of hereditary stomatocytosis will improve the establishment of the diagnosis and the management of patients
Genetic Markers of Cardiovascular Disease in Epilepsy
EpilepsySeizures3 moreEpilepsy is a common condition which affects over 3 million people in the US. Patients with uncontrolled epilepsy have a lifetime risk of sudden unexpected death (SUDEP) of 35%, which is greatest in those under 40 years of age. The exact mechanisms and causes are not understood but can be due to underlying conditions which affect the heart and brain, which may lead to dangerous heart rhythms and death. Some of these conditions which affect heart and brain have an identifiable genetic cause. This study aims to identify known genetic causes of heart rhythm and sudden death related disorders in patients with epilepsy.
Distribution of Cell-cell Junction Proteins in Arrhythmic Disorders
Arrhythmogenic Right Ventricular DysplasiaBrugada Syndrome1 moreEvery week in the UK, 12 apparently healthy and fit individuals under the age of 35 die suddenly, a tragic event known as sudden cardiac death (SCD). The investigators have shown that heritable cardiac disorders affect the distribution of proteins at the cardiac cell-cell junctions, the areas where cardiac cells are mechanically and electrically coupled. This knowledge has helped the investigators diagnose specific heart disorders in individuals thus reducing the risk and incidence of SCD. Yet, the primary material required is a heart sample. A heart biopsy is an invasive process that comes with risks and is not performed unless absolutely necessary. And it is impossible to obtain a heart sample from an individual that may be carrying a disease-causing mutation (and hence be at risk of SCD) but does not yet show evidence of disease manifestation. The investigators recently showed that buccal cells show changes in protein distribution equivalent to those exhibited by the heart,hence providing them with a surrogate tissue for the myocardium. The investigators aim to use buccal smears as a means to identify those at risk of SCD. Patients regularly seen at the cardiology clinics at St. George's Hospital can participate in the study. The investigators shall take a buccal smear simply by rubbing a soft brush at the inside of their cheek and smearing it on a slide. Most individuals willing to participate in the study will only have to provide the investigators with a sample once. However, in selected cases (for instance, if the patients show disease progression or have a change in medication) they may be asked to provide the investigators with a subsequent sample during one of their scheduled follow-up visits. The process takes only a few seconds, is totally risk- and pain-free and it is anticipated to have great implications in diagnosis and patient management.
Safety of Local Dental Anesthesia in Patients With Cardiac Channelopathies
ChannelopathiesBrugada Syndrome3 morePatients with cardiac channelopathies needing restorative dental treatment will be included in two sessions of the study, using local dental anesthetic: lidocaine 2% with epinephrine and lidocaine 2% without vasoconstrictor. The safety of the use of two cartridges (3.6 mL) will be evaluated. The patients will be their own control and will be assessed by Holter monitoring for 28 hours, blood pressure measurement and anxiety measuring.
Post-mortem Genetic Testing
Cardiac Ion ChannelopathyThis is a prospective observational study to examine the incidence of cardiac ion channelopathies in unexplained still births.
Defining the Electrocardiographic Effect of Propofol on the Ajmaline Provocation Drug Challenge:...
Brugada SyndromeChannelopathies2 moreBackground: Brugada Syndrome is an inherited channelopathy associated with risk of ventricular fibrillation and sudden cardiac death in a structurally normal heart. The diagnosis is based on the characteristic electrocardiographic pattern (coved type STsegment elevation, 2mm followed by a negative T-wave in one or more of the right precordial leads V1 to V2), noted spontaneously or upon administration of a sodiumchannel blocker, such as Ajmaline. The majority of adults screened for Brugada Syndrome, undergo the Ajmaline provocation-test awake. Ajmaline is therefore injected continuously, with incremental steps through an intravenous placed catheter, according to cardiological protocols. In a subpopulation of anxious adults, or when another electrophysiological procedure is required at the same time, sedation or general anaesthesia is provided. Similarly, in the paediatric population, it is common practice to perform the challenge test under sedation. Based on the sodium channel blocking properties of propofol, it is not unthinkable that anaesthetic agents might interact with the pharmacodynamic or pharmacokinetic effects of Ajmaline on the myocardial sodium channels. Existence of such interaction would implicate altered diagnostic value of the Ajmaline-provocation-test for patients that undergo the challenge under general anaesthesia. Objective: The goal of this study is to evaluate if the Ajmaline-provocation-test results in altered electrocardiographic effects when performed under general anaesthesia with propofol. Study-design: A prospective observational study. Study population: Patients are eligible for inclusion if they have been diagnosed with Brugada Syndrome, are American Society of Anaesthesiologists (ASA) 2 - 4, older than 18 years and are scheduled for epicardial ablation. Exclusion criteria are known allergy for propofol, a body mass index (BMI) above 35 for female and 42 for male patients, obstetric patients, critical illness, conditions that exclude continuous propofol infusion due to higher risk for propofol infusion syndrome (PRIS), such as mitochondrial disease, fatty acid oxidation disorder, co-enzyme Q deficiency and any other condition that renders the patient unfit for elective surgery. Intervention: This study is prospective, observational. Main study parameters/endpoints: The primary endpoints are changes in the ST-, Jp-, QRS-, T(p-e)-segments and T(p-e)/QT -ratio changes during steady-state anaesthesia. The secondary endpoint is the occurrence of de novo arrhythmias. Nature and extent of the burden and risks associated with participation: This is an observational study; therefore, the risks associated are no other than those associated with the intervention itself. No additional blood-samples, tests or consults are necessitated during participation; therefore, no extra burden is associated.
Sudden Cardiac Death - Screening Of Risk Factors
Sudden Cardiac DeathCardiomyopathies1 moreThe investigators have created a way of quickly collecting information in a large scale young population regarding the presence of some severity indicators that may allow us to classify them into: seemingly "low risk" and possible "elevated risk" for the presence of heart disease. It would have to be a short questionnaire, in order to receive a great adherence but that could simultaneously provide precise information, with an adequate description of symptoms and warning signs, in a way that a triage in the young adult population could be performed in the general young adult population in order to select individuals with an indication for personalized clinical evaluation and possible need of complementary diagnostic means. Based on this premise the investigators have developed a fast-response questionnaire named the Sudden Cardiac Death Screening Of risk factorS (SCD-SOS). This questionnaire has already been tested in a population of approximately 1500 young adults, and some changes have been introduced in order to refine its performance. To best of the investigators knowledge, there are no large scale European surveys estimating the prevalence of cardiac disease and associated clinical symptoms in a non-selected (non-athlete) population of this age group. Purpose: To screen a young adult population from central regional of Portugal for heart disease possibly associated to a high risk of Sudden Cardiac Death (SCD). To determine the national prevalence of clinical symptoms of heart disease and of heart disease with increased risk for SCD in this age group. To detect young adults in risk of SCD and with an indication for evaluation by a cardiologist, and possible need of: medical treatment electrophysiologic (EP) study and percutaneous ablation an implantable cardiovertor defibrillator a pacemaker other type of specialized cardiac intervention
Painful Channelopathies Study
ErythromelalgiaPain Insensitivity3 moreTo understand the pathophysiological basis of heritable pain syndromes. This will consist of a number of components: Determine the genetic basis for heritable pain syndromes. Investigate the pain symptoms, psychological co-morbidity and quality of life in patients with heritable pain syndromes. Use quantitative sensory testing to investigate abnormalities in sensory processing. Use imaging modalities to investigate the neural correlates of pain perception in heritable channelopathies. In select patients to perform skin biopsy to determine if there has been any damage to C-fibres. To perform skin biopsy in order to culture fibroblasts and neural crest stem cells for future studies into the molecular basis of altered pain perception. To use neurophysiological tests, the axon reflex, and conditioning challenges to determine how peripheral nerves, in heritable channelopathies and unusual pain syndromes, have been altered. Microneurographic recordings for directly detecting the function of pain fibres in peripheral nerves. Knowledge gained from the study will be used to aid the further development of genetic testing and specific pain questionnaires for the diagnosis of heritable pain syndromes secondary to channelopathies. Ultimately better knowledge of underlying pathophysiology in these heritable pain conditions may inform the development of novel treatments.