125 Clinical Trials for Various Conditions
Out-of-hospital arrest can occur from multiple etiologies. In patients without an obvious reason for the sudden-death event, diagnostic evaluation is not clear. This study is to determine if early imaging with a head-to-pelvis CT scan may improve diagnostic accuracy, speed of diagnosis and potentially clinical outcomes.
This study is an observational study to determine predictors of sudden cardiac death or appropriate ICD therapy in patients with non-ischemic cardiomyopathy. Patients will be followed for 36 months for the occurrence of sudden cardiac death
Despite pharmacologic advances for the treatment of congestive heart failure (HF), sudden cardiac death (SCD) and pump failure remain the leading causes of mortality in patients with HF. Although, SCD is poorly understood, implantable cardiac defibrillators (ICD) have been shown to be an effective, but costly therapy in preventing SCD. At present, left ventricular systolic dysfunction is our best independent predictor of SCD, but only moderately predicts those patients who will eventually benefit from the placement of an ICD and, in most cases, left ventricular (LV) systolic dysfunction is a non-modifiable risk factor once acquired. As a result, there exists an intensive search for biomarkers that could improve the prediction of SCD and have the potential for risk factor modification. Experimental and clinical evidence has established that inflammation plays a critical role in stable coronary disease, plaque rupture, acute myocardial infarction, heart failure, and SCD. Studies at our institution have demonstrated that elevated levels of hsCRP and Interleukin-6 are predictive of arrhythmic SCD; however, the mechanism of causing this increased risk is unclear. Another well-known risk factor for SCD is abnormal sympathetic innervation. The most robust clinical test of sympathetic innervation to date is Iodine-123 Metaiodobenzylguanidine (MIBG) imaging with gamma scintigraphy. MIBG imaging has emerged as one of our strongest predictors of SCD by detecting sympathetic nervous system abnormalities in patients with HF. Preclinical and clinical evidence suggests that myocardial inflammation adversely affects myocardial innervation. Based on these findings, the investigators hypothesize that elevated levels of inflammatory biomarkers are associated with abnormal sympathetic innervation as measured by MIBG imaging. The investigators aim to establish the strength of this association. This proposal will leverage unique access to the largest, most extensively phenotyped cohort of patients who have undergone ICD implantation for primary prevention of SCD, the PRospective Observational Study of the ICD in SCD, (PROSE-ICD).
This study explores the hypothesis that wearable defibrillators can impact mortality by reducing sudden death during the first three months after a heart attack in persons with high risk for life-threatening arrhythmias.
The purpose of this study is to identify patients with cardiac sarcoidosis who may be at risk for sudden death.
People with epilepsy are at a higher risk for sudden unexpected death than the general population. Sudden unexpected death in epilepsy (SUDEP) is a major cause of death in this population, accounting for 10-50% of deaths for those with epilepsy. The risk for SUDEP is particularly high for those with refractory epilepsy. Several lines of evidence support a cardiac mechanism for SUDEP. This study plans to determine: 1. the frequency and types of cardiac arrhythmias that occur in this population and 2. whether these are increased above the general population in the same age group. Additionally, these data will be correlated to specific clinical data, including seizure history, anticonvulsant medications, and any accompanying clinical symptoms.
Female sex is an independent risk factor for the potentially fatal drug-induced arrhythmia (irregular heartbeat) known as torsades de pointes (TdP), which is associated with prolongation of the corrected QT (QTc) interval on the electrocardiogram (ECG). Mechanisms for this increased risk in women are not well-understood. QTc interval duration has been shown to fluctuate throughout the phases of the menstrual cycle. Evidence indicates that the QTc interval response to drugs that may cause TdP is greater during the menses and ovulation phases of the menstrual cycle, during which serum progesterone concentrations are lowest, and lesser during the luteal phase, during which serum progesterone concentrations are highest. Additional evidence from our laboratory suggests that progesterone may be protective against TdP. Specific Aim 1: Establish the influence of oral progesterone administration as a preventive method by which to diminish the degree of drug-induced QT interval prolongation in women. Working hypothesis: Oral progesterone administration effectively attenuates enhanced drug-induced QT interval response in women. To test this hypothesis, progesterone or placebo will be administered in a crossover fashion to women during the menses phase of the menstrual cycle. QTc interval response to low-dose ibutilide, a drug known to lengthen the QT interval, will be assessed. The primary endpoint will be individually-corrected QT interval (QTcI) response to ibutilide, in the presence and absence of progesterone, which will be assessed by: 1) Effect on maximum change in QTcI, and 2) Area under the QTcI interval-time curves (AUEC). At the conclusion of this study, we will have established that oral progesterone administration is a safe and effective method of attenuating drug-induced QT interval prolongation.
This research will be a prospective, cohort study to determine if mothers of infants/newborns are more willing to complete CPR training using a 22-minute instructional DVD and infant manikin versus traditional four hour didactic instruction. Study Hypothesis: A 22-minute instructional DVD and infant manikin will be an effective and preferred tool for teaching mothers of infants infant CPR. Objectives 1. To determine if mothers of infants are more likely to complete infant CPR training with a 22-minute instructional DVD and infant manikin, than by attending a traditional CPR class. 2. To determine if learning infant CPR with a 22-minute instructional DVD and infant manikin is as effective as attending traditional infant CPR class. 3. To examine the number of mothers that were offered the opportunity to learn infant CPR either as part of their prenatal classes, or upon the birth of their infant. 4. To examine the number of mothers who have been previously trained in CPR. 5. To examine the reasons that mothers have been previously trained in CPR (e.g., mandated by work/career vs. personal reasons). 6. To examine the multiplier effect of an at home CPR education using a 22-minute instructional DVD and infant manikin at the time of the follow up phone call.
Background: People with sickle cell disease (SCD) have problems with their heart, brain, kidneys, liver, and lungs as they age. These problems may improve after transplant. Researchers want to learn how and why this happens. Objective: To study the benefits of treatments that are intended to cure SCD. Eligibility: People aged 18 and older with SCD who are either receiving curative therapy in the next 3 months or don t have any plans to receive a curative therapy in the next 2 years. Design: At their first visit, participants will be screened with their medical history and a physical exam. Participants will then have a baseline visit. This will take about a week to complete and will include: Blood and heart tests MRI of the brain, heart, and lungs. Participants will lie on a bed that will move into the MRI scanner. Special padding may be placed around their head to keep it still. Interactive games. Participants will complete computer games that test memory, attention, problem solving, language, spatial orientation, processing speed, and emotion. Questionnaire rating quality of life Iothalamate test. An IV catheter will be placed into a vein. A contrast agent will be injected through the IV. Blood will then be collected at different time points. Lung function tests and a 6-minute walk test Vibration controlled transient elastography. A probe placed on the abdomen will measure liver scarring. DOS test. A light attached to the finger or toe will measure blood oxygen. Participants will have an end-of-study visit about 2 years after their baseline visit. This will include repeats of the baseline visit tests.
The purpose of the study is to evaluate the safety and efficacy of wearable defibrillator use in patients with left ventricular dysfunction or advanced heart failure symptoms, who have a high-risk for sudden cardiac death but are either not eligible for an implantable defibrillator under current guidelines or are not able to receive the device due to their condition.
This study will assess whether an implantable defibrillator will increase the likelihood of survival in patients who have had a heart attack, have abnormal test results from a 24 hour heart monitor, and who have low normal heart function.
This is a prospective study to evaluating the ability of the PD2i Cardiac Analyzer to predict the risk of serious heart rhythm abnormalities in high-risk patients that do not already have an Implantable Cardioverter Defibrillator.
Sudden cardiac death continues to be a major contributor to mortality in patients with ischemic cardiomyopathy. While implantable defibrillators can prevent death from ventricular arrhythmias, our current approach to identify patients at highest risk primarily rests on demonstrating a reduction in left ventricular ejection fraction less than 35%. The purpose of this observational cohort study is to prospectively test whether this can be enhanced by quantifying the amount of sympathetic denervation, left ventricular end-diastolic volume or brain natriuretic peptide levels.
The purpose of the study is to see how effective a drug called ranolazine is in reducing the risk of ventricular arrhythmia and death in people with implantable cardioverter-defibrillators (ICDs). This drug will be used with standard medications that is routinely prescribed in enrolled patients.
This study will review medical information collected on children and adolescents with hypertrophic cardiomyopathy (HCM) to try to identify risk factors for arrhythmias (abnormal heart rhythms) in these patients and better guide the choice of treatment options for them. Arrhythmias arising from the ventricle (lower heart chamber) can cause dizziness, fainting or cardiac arrest. Predictors of arrhythmias in adult HCM patients may not apply to children and teenagers with HCM. Children and adolescents 21 years of age or younger who were diagnosed with HCM and evaluated in the National Heart Lung and Blood Institute's Cardiology Branch between 1977 and 2002 may be eligible for this study. Participants do not undergo any further testing or data gathering beyond a review of their medical records; only existing data previously collected for research purposes are used. Medical records are reviewed for age of the patient on admission to the NIH; family history of sudden death, fainting, exercise-induced low blood pressure, and results of tests on heart structure and function.
This study will explore what may cause people with sickle cell anemia to have heart problems and an increased risk of sudden death. People 18 years of age and older with sickle cell anemia may be eligible for this study. Candidates are screened with a medical history and physical examination, electrocardiogram (EKG), echocardiogram (heart ultrasound), and blood tests. Participants undergo the following tests and procedures: * Holter monitoring: The patient wears a small, battery-operated device to record heart rate and rhythm over 24 to 48 hours. * QRST surface mapping: An EKG using 64 electrodes is done at rest and during exercise to provide a detailed look at the heart and its conduction system. * Chest x-rays are taken to examine the lungs. * Bicycle exercise echocardiography test: Blood pressure, pulse, heart rhythm and oxygen use are monitored while the patient exercises on a stationary bicycle. Ultrasound pictures are also obtained during the exercise. * Echocardiogram: A heart ultrasound is done to check how well the heart is pumping blood. * Pulmonary artery catheterization: A catheter (plastic tube) is inserted into a vein and advanced to the chambers of the heart, through the heart valve and into the lung artery. The pressures in the heart and lung blood vessels are measured while the patient is resting and during exercise, with the bed tilted up and down, and after giving 500 mls of fluid into a vein. * Blood tests are done to measure a hormone called brain natriuretic peptide, which can increase with the development of heart failure, and nitrite, a substance that can affect blood vessel dilation. Some blood is stored to test for inflammatory markers and for possible future gene and protein analysis. * Cardiac magnetic resonance imaging (cMRI): The patient lies in a donut-shaped magnet while pictures of the heart are obtained using a magnetic field and radio waves. Earplugs are worn to muffle the loud sounds that occur with electrical switching of the magnetic fields. A contrast agent called gadolinium may be injected to enhance the quality of the images. * Invasive electrocardiographic (reveal) monitoring: This procedure permits study of the heart rhythms over a long time period. A small device is placed just under the skin on the left side of the chest. It can be left in for up to 14 months to monitor the heartbeat continuously during this time.
This study will examine the usefulness of a new test called an isoproterenol challenge in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and family members who may have the disease but do not have clear-cut evidence of it. ARVC is a rare condition that runs in families. Heart muscle is replaced with fatty, scar-like tissue, especially in the right ventricle (lower pumping chamber of the heart), and can sometimes extend to the left ventricle (the main pumping chamber). The fat can interfere with the heartbeat, producing abnormal heart rhythms, such as ventricular tachycardia (VT) - a very fast heartbeat that can cause sudden death, especially in young people. Isoproterenol is a drug that increases heart rate and heart muscle contractions. In isoproterenol challenge, subjects are given increasing doses of the drug through a catheter (see details below) to try to produce an abnormal heart rhythm. ARVC is hard to diagnose with current tests. This study will see if isoproterenol challenge provokes VT in patients with the disease and can confirm the diagnosis; if it can detect the disease in family members better than currently available tests; and if it provokes abnormal rhythms in healthy control subjects. In addition, the study will explore the genetics of ARVC and determine whether infection could contribute to its development. Patients with ARVC, their family members, and normal volunteers 18 years of age and older may be eligible for this study. Candidates are screened with a medical history and physical examination, electrocardiogram (EKG), treadmill and bicycle exercise testing, and an echocardiogram (ultrasound test of the heart). Participants undergo the following tests and procedures: * Blood tests - Blood is collected to study the genetics of ARVC, to test for evidence of old infections, and to measure brain natriuretic peptide - a hormone that can increase with development of heart failure. * Heart magnetic resonance imaging (MRI). This test looks at heart structure and function. MRI uses a magnetic field and radio waves to produce images of body tissues and organs. The subject lies on a table that is moved into the scanner (a narrow cylinder), wearing earplugs to muffle loud knocking sounds that occur during the scanning process. At some time during the test, the subject is given a contrast agent called gadolinium through a catheter (thin, flexible tube) in a vein to improve the scan pictures. The scan time varies from 30 to 90 minutes, with most scans lasting 60 minutes. (Control subjects do not undergo MRI.) * Isoproterenol challenge. Subjects are given increasing doses of isoproterenol through a catheter until the heart rate reaches 100 to 120 beats per minute for no more than 1 hour. A special EKG records heart rhythm during the test and an echocardiogram records right and left ventricular function. * QRST surface mapping EKG. This special EKG, done with 64 or 120 leads, maps abnormalities of heart rhythm and cardiac conduction during the isoproterenol challenge. These tests are like a regular EKG, except that more leads are placed on the chest, and on the back as well. Patients and family members who wish to have follow-up visits may return to the NIH Clinical Center once a year for 5 years for guidance about therapy based on clinical considerations and new information or investigations.
Genetically inherited heart diseases (familial cardiopathies) are conditions affecting the heart passed on to family members by abnormalities in genetic information. These conditions are responsible for many heart related deaths and illnesses. Researchers are interested in learning more about the specific genetic abnormalities causing heart diseases. In addition, they would like to find out how these abnormal genes can contribute to the development of other medical problems. In order to do this, researchers plan to study patients and family members of patients diagnosed with genetically inherited heart disease. Those people participating in the study will undergo a variety of tests including blood tests, echocardiograms, and magnetic resonance imaging studies (MRI). These tests will be used to help researchers find the genetic problem causing the familial cardiopathy. Researchers hope that the information gathered from this study can be used to develop better medical care through early diagnosis, management, and treatment plans.
The purpose of this study is to learn about heart and skeletal muscle problems related to neuroacanthocytosis (also called Mcleod's syndrome and Levine-Critchley disease). This inherited condition causes problems of blood, brain, heart and muscle function. About 60 percent of patients have an unusual heart muscle abnormality that increases the risk of sudden death. Although the molecular (genetic) changes responsible for neuroacanthocytosis have recently been identified, the heart and skeletal muscle problems are not well understood. This study will try to correlate the specific genetic abnormalities with the clinical features of the disease and identify possible causes of sudden death. Patients and first degree relatives of patients with neuroacanthocytosis 18 years of age or older may be eligible for this study. Participants will be admitted to the National Institutes of Health Clinical Center for 2 to 5 days for the following tests: * Electrocardiogram - to measure the electrical function of the heart * Echocardiogram - uses ultrasound to measure heart thickness and detect heart vessel obstructions * Cardiac magnetic resonance imaging (MRI) - uses a magnetic field and radio waves to provide pictures of the heart for measurements of muscle thickness and muscle function * Exercise testing on a stationary bicycle - to measure and record symptoms during exercise, exercise duration, heart rate and blood pressure, oxygen consumption and aerobic threshold * Holter monitoring - uses a device attached to the chest for continuous recording of heart rhythms * Blood tests - to look for muscle damage, to exclude other causes of muscle disease, and to perform DNA (genetic) testing * Neurological consultation - to test muscle function, coordination and tests of certain brain functions such as memory and concentration Patients with evidence of muscle disease may also undergo a muscle biopsy. This is done under a local anesthetic and possibly small amounts of sedation. A small area of skin over a large arm muscle (biceps) is numbed, a short incision is made and a small sample of muscle tissue is removed for microscopic examination. Patients with evidence of heart disease may also undergo the following additional tests: * Cardiac catheterization and electrophysiological study - to determine the extent of heart disease and study abnormal heart rhythms. Cardiac catheterization is done under mild sedation. The groin is numbed with an anesthetic and catheters (thin plastic tubes) are inserted and passed through the blood vessels into the chambers of the heart. Pressures inside the heart are measured and pictures may be taken of the heart arteries. During this procedure an electrophysiology test may be done to study abnormal heart rhythms. * Cardiac biopsy - to examine heart muscle tissue. This may be done at the end of the cardiac catheterization. Small samples of heart muscle are obtained using a fine instrument passed through the catheter in the groin. Family members who do not have signs of heart or muscle disease will only undergo non-invasive tests. All participants will be given the results of all tests and treatment options will be discussed.
The goal of this feasibility study is to test the Korus smart mattress in healthy volunteers. The main questions it aims to answer are: * Can Korus accurately detect body position in bed (left, right, supine, prone) * Can Korus reposition the subject from a prone to recovery (sideways) position? Participants will be asked to lie down on Korus and turn into various positions; when the prone position is detected, they will be repositioned.
The purpose is to increase the understanding of the characteristics, circumstances, medical histories and pathologies of children from ages 11 months through 18 years who have died suddenly and unexpectedly, and in some instances, without explanation. The SUDC Registry and Research Collaborative will analyze cases of sudden unexpected deaths in these children to understand risk factors and causes, and develop preventative measures.
The current standard of care for ventricular tachycardia (VT) includes the use of medicine called anti-arrhythmic drugs (AADs) and Implantable Cardioverter Defibrillator (ICD) therapy. These treatments are used to terminate the irregular heartbeats and bring the heart back to a normal rhythm. Catheter ablation is a procedure used to eliminate (damage) the heart cells causing the arrhythmia. Patients eligible for this may benefit from an ablation procedure in addition to an ICD to treat their VT condition or risk of developing VT. This study aims to show that treating VT with catheter ablation, if performed preemptively at the time of ICD implantation, will reduce subsequent recurrent VT, ICD shocks, and lead to improved survival.
The purpose of the study is to determine whether prolonged paced QRS duration is a marker of sudden cardiac death in subjects with implantable cardioverter-defibrillators (ICD).
The purpose of this study is to determine whether a blunted heart rate response to regadenoson is an independent predictor of sudden cardiac death.
The main purpose of this study is to develop a North American registry for SUDEP cases; requesting family members of epilepsy patients who died suddenly of unclear causes (SUDEP) to contact the study team. The family members who decide to participate in the study will be asked to complete a brief telephone interview about their loved one's epilepsy and seizure history and the circumstances of his or her death. If the death has occurred within the past 24 hours, and the family is willing to consider donating tissue to the study, the subject will be transferred to the Autism Tissue Program, and the remainder of the phone interview will be conducted at a later time. In addition to the phone interview, the family will be asked to provide access to the deceased's medical records. Any costs involved in obtaining medical records will be covered by the study, and all medical information will remain completely confidential.
The overall purpose of this investigation is to better understand factors contributing to the high incidence of prone sleep positioning in African-American infants. In addition, the investigators are interested in investigating other races and ethinicities to understand their beliefs and perceptions and determine differences socioeconomically and socioculturally within and between groups. The investigators will address the following specific aims: (-) To compare knowledge, attitudes, and practices regarding infant sleep position in parents of higher and lower SES. (-) To identify risk factors for non-use of recommended supine sleep position in families with higher and lower SES (-) to develop a phenomenologic understanding of the decisions made by parents of higher SES and lower SES who do nt use recommended supine sleep position, using qualitative techniques.
Sudden cardiac death (SCD) poses a significant health care challenge with high annual incidence and low survival rates. Implantable cardioverter defibrillators (ICDs) prevent SCD in patients with poor heart function. However, the critical survival benefit afforded by the devices is accompanied by short and long-term complications and a high economic burden. Moreover, in using current practice guidelines of reduced heart function, specifically left ventricular ejection fraction (LVEF)≤35%, as the main determining factor for patient selection, only a minority of patients actually benefit from ICD therapy (\<25% in 5 years). There is an essential need for more robust diagnostic approaches to SCD risk stratification. This project examines the hypothesis that structural abnormalities of the heart itself, above and beyond global LV dysfunction, are important predictors of SCD risk since they indicate the presence of the abnormal tissue substrate required for the abnormal electrical circuits and heart rhythms that actually lead to SCD. Information about the heart's structure will be obtained from cardiac magnetic resonance imaging and used in combination with a number of other clinical risk factors to see if certain characteristics can better predict patients at risk for SCD.
The overall hypothesis of this study is that subtle interactions between structural (substrate) and functional (trigger) abnormalities of the heart, some of which are genetically-determined, can be used to identify patients at high risk of sudden cardiac death (SCD). Such information may be used to better define patients most likely to benefit from replacement of an internal defibrillator (ICD). The prospective, observational study to enroll, categorize and follow patients who receive an ICD pulse generator replacement for primary prevention of SCD (PROSe-ICD) was established to : 1. to gain a better understanding of the biological mechanisms that predispose to SCD 2. to develop readily determined clinical, electrocardiographic, genetic and blood protein markers identify patients with an increased risk of dying suddenly
As an ancillary study to the KEEPS study (see ClinicalTrials.gov Identifier: NCT00154180), the primary purpose is to measure effects of estrogen vs. placebo in menopausal women, on autonomic function and repolarization; both measured non-invasively via holter monitoring.
This is a pilot study to find a correlation between MRI and ICD therapy in patients with known cardiomyopathies, aiming to determine if cardiac scarring identified by MRI correlates with ventricular arrhythmias and the occurrence of ICD therapy.