View clinical trials related to Arrhythmias, Cardiac.
Filter by:The purpose of this study is to evaluate product performance of Magnetic Resonance (MR) Conditional Cardiac Implantable Electronic Devices (CIED) following 3 tesla (3T) MRI exposure. This will be achieved by evaluating the changes in pacing capture threshold (PCT) measurements following 3T MRI scan exposure. This study is required by FDA as a condition of approval of 3T MRI compatible labeling of applicable CIED systems. This study is conducted within Medtronic's post-market surveillance platform, the Product Surveillance Registry (PSR).
Currently loop recorders diagnose arrhythmias and send automatic alerts to physicians based on R to R relationships only. We believe arrhythmia diagnostics could be improved if accurate detection of P and T waves as well as QRS complexes were possible. There is no technique available for long term outpatient monitoring of QT intervals for patient at risk of torsade de pointes when receiving QT prolonging drugs. We believe that if an accurate T wave detection algorithm were developed loop recorders could be used to monitor the QT interval, and perhaps even provide alerts for patients at risk. The objective of this study is to see if an algorithm can be developed to accurately define P and T waves using data from an implantable loop recorder.
This study is to assess if subjects receiving a clinically indicated implanted cardiac pacemaker or defibrillator can be safely discharge home the same day of the procedure.
Since the invention of electrocardiogram (ECG), ECG has been an important part of clinical practice. A primary reason for the popularity of the ECG is that it is non-invasive and can be performed in any patient by placing electrodes on the skin. The present methods of ECG recording focus on detecting electrical signals from the heart. the investigators propose that with high frequency sampling and high pass filtering, the investigators can also record SNA from the skin. The somata of the subcutaneous sympathetic nerves on the skin are located at the ipsilateral cervical and stellate ganglia. Because the left stellate ganglion nerve activity (SGNA) is known to trigger cardiac arrhythmias, including AF, VF and VF, It is possible that skin SNA can also be used for arrhythmia prediction. the investigators tested that hypothesis in our preclinical studies (supported by R01 HL71140) using canine models. The results showed that subcutaneous nerve activity (SCNA) recorded with implanted electrodes can be used to estimate stellate ganglion nerve activity(SGNA) in normal dogs and in a canine model of ventricular arrhythmia and sudden death. the investigators also showed that SCNA is more accurate than heart rate variability in estimating cardiac sympathetic tone in ambulatory dogs with myocardial infarction.Therefore, SKNA and SCNA may be useful in estimating cardiac sympathetic tone. In addition to studying the autonomic mechanisms of cardiac arrhythmia, these new methods may have broad application in studying both cardiac and non-cardiac diseases. For example, sympathetic tone is important in the pathogenesis of heart failure, atherosclerosis, peripheral neuropathies, epilepsy, vasovagal syncope, renal failure, hypertension and many others diseases. Direct SKNA and SCNA recording may provide new approaches to study the mechanisms of these common diseases. SKNA recording may also have immediate clinical applications by assisting in the diagnosis and treatment of hyperhidrosis (sweaty palms), paralysis, stroke, diabetes, and neuromuscular diseases. It may be used to assist biofeedback monitoring performed by neurologists to control neuropsychiatric disorders. Because of these potential clinical and commercial applications, the investigators propose that this research project is significant. b. Innovation - Using conventional electrodes on the skin to record SNA. The neuECG utilizes the conventional skin electrodes that are widely used in health care facilities. Skin SNA had been recorded using microneurography techniques, and had been estimated using cutaneous blood flow (vasodilator responses) skin temperature, skin conductance and sweat release. However, microneurography cannot be used in ambulatory patients. The other methods are not direct measurements of SNA. neuECG is the first method that can directly and non-invasively measure the SNA from the skin. - Automated real-time signal processing. the investigators will develop signal processing software to automatically eliminate noise, such as that generated by muscle contraction, electrical appliances, body motion, respiration, and radiofrequency signals. The remaining signals are then processed to separately display in real time to provide health care providers a new method to instantly estimate sympathetic tone. The ECG signals are used for automated arrhythmia detection while the SNA signals are available for risk stratification. This approach allows us to improve and broaden the clinical application of Einthoven's original invention by simultaneous detecting ECG and SNA from the skin. - SKNA patterns as new biomarkers. the investigators have identified unique SKNA patterns that precede the onset of human AF. If proven correct by Specific Aim 3, this new biomarker can help physicians to estimate the arrhythmia risk and to predict the efficacy of catheter ablation for AF.
The primary objective of the study is to determine the safety of MRI in patients with non-MRI conditional pacemakers. The secondary objective is to determine if there are clinically relevant parameter changes in the devices.
Organized ventricular arrhythmias (ventricular tachycardia (VT), torsades de pointes (TdP) and ventricular fibrillation (VF)) represent a major event in the clinical history of a patient and they can lead to hemodynamic instability and sudden cardiac death (SCD). Recurrences of ventricular arrhythmias and electrical instability have exponentially increased in the last decades and a new clinical entity called "electrical storm" (ES) has emerged as major morbidity and mortality factor. The ES is defined as a cluster of 3 or more sustained ventricular arrhythmias within 24 hours, or a sustained ventricular tachycardia lasting 12 hours or more and that does not respond to treatments. Most of the patients presenting ES are already implanted with an ICD. This is due to 3 factors: first, patients with ICD implant are at higher risk to develop ventricular arrhythmias for the cardiac disease that led to the ICD implant. Second, the device records and treats also asymptomatic or poor symptomatic arrhythmic episodes that otherwise would not be detected. Third, and more important, the device gives the possibility to survive to an arrhythmic episode, making it possible for the patient to experience an ES. The incidence of ES is debated in different studies and ranges from 10 to 60% in patients with ICD for secondary prevention and from 4 to 7% in patients with ICD for primary prevention. The aim of the ELECTRA registry is twofold: 1. To create an international registry on clinical features, optimal therapy, ablation strategy, prognosis and the effect of ICD programming on patients with ES. 2. To use the data derived from the registry for a prospective, observational study on mortality and rehospitalization rate in patients with ES.
The purpose of the study is to compare standard, single chamber transvenous ICD to sub-cutaneous ICD in occurrence of perioperative and long term device related complications and failed appropriate clinical shocks and arrhythmic death.
The purpose of this study is to identify markers of increased risk for incident ventricular arrhythmias and cardiovascular events in patients already being treated with an implantable cardioverter-defibrillator (ICD) by exploring patient history and clinical findings, biological markers, ECG markers, and echocardiographic markers.
Rationale: Sympathetic activity plays an important role in the pathogenesis of ventricular tachyarrhythmia. Previous studies have shown evidence of significant heritable influences on individual responses to adrenergic stimulation. Catheter-based renal sympathetic denervation (RDN) is a novel treatment option for patients with resistant hypertension, proved to reduce local and whole-body sympathetic activity. The investigators hypothesize that percutaneous transluminal electrical stimulation of the sympathetic nerve bundles in the renal arteries will cause ventricular arrhythmias and renal denervation will suppress these arrhythmias in patients with sympathetic ventricular arrhythmias. Objective: This study will investigate the effects of renal nerve stimulation before and after percutaneous transluminal RDN on cardiac excitable properties including induction of ventricular tachy-arrhythmias before and after RDN in six studies, i.e. patients with catecholaminergic polymorphic ventricular tachycardia (CPVT), long QT syndrome and arrhythmogenic right ventricular cardiomyopathy (ARVC), sympathetically driven ventricular arrhythmias, hypertrophic cardiomyopathy (HCM), dilated non-ischemic cardiomyopathy (DCM) and ischemic cardiomyopathy (ICM). The aim of the six studies is to assess the anti-arrhythmic effects of RDN in patients with sympathetic ventricular tachy-arrhythmias. Study design: Investigator initiated, multi centre, six pretest-posttest design studies. Study population: Patients with recurrent sympathetically driven ventricular arrhythmia despite optimal pharmacological therapy. Patients should be diagnosed with CPVT and certain types of long QT syndrome, ARVC, HCM, DCM and ICM. Eligible patients will be in the age category of 18-85 year. Intervention: RDN will be performed according to routine clinical practice. Prior to the ablation procedure, catheter mapping of the renal arteries will be performed according to routine clinical practice. Clinical and biological responses to transluminal electrical renal nerve stimulation will be assessed before and after RDN. Study endpoints: - Main procedural study endpoint: Induction of ventricular arrhythmias in response to renal nerve stimulation prior to RDN and absence of renal nerves stimulation induced ventricular arrhythmias after RDN. - Main clinical study endpoint: Development of ventricular arrhythmia during exercise stress testing performed 6 months after procedure. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: In several studies, it was shown that RDN was safe. The intervention resulted in significantly better control of blood pressure with less medication, and beneficial changes in heart rate variability, autonomic sympathetic balance, renal arteriolar function, and a higher success of atrial fibrillation prevention. In case reports and case series, RDN had a favourable effect in patients with sympathetic drug refractory ventricular tachy-arrhythmias.
The research goal is to continue to add to the extensive body of peer-reviewed evidence that demonstrates MRI may be safely performed in patients with cIEDs, after they have been evaluated and cleared by cardiology. This study will allow the researchers to collect data from the facilities ongoing clinical practice regarding the number and types of any adverse clinical reactions, and also to document any changes in the implanted cardiac device that may have occurred during the MRI scan. The researchers will also be assessing the results of the MRI and how the imaging findings impact patient care and the clinical outcome of the patient. This data will then be presented to the FDA and the Centers for Medicare and Medicaid Services to further influence federal guidelines and payment structures.