Active clinical trials for "Tachycardia"

The investigators propose to test the hypothesis that the sympathetic nervous system contributes to the cardiovascular and inflammatory abnormalities present in the chronic fatigue syndrome (CFS) and, in particular in the subset of patients characterized by postural tachycardia syndrome (POTS). CFS and POTS are seen mostly in otherwise normal young women, and are the cause of significant disability. A substantial proportion of patients referred for evaluation of POTS met diagnostic criteria for CFS and, conversely, a subset of patients referred for treatment for CFS have POTS. The investigators hypothesize that sympathetic activation underlies the pathophysiology of patients in whom CFS and POTS overlap (CFS-P).

Primary objective is to evaluate the safety and performance of the implanted Subcutaneous implantable cardioverter defibrillator (S-ICD) system. A maximum of 10 subjects were to be enrolled and followed for one month to collect data on the safety, efficacy, and performance of the implanted S-ICD system. Additionally, patient comfort will be assessed as will cosmetic outcome.

The purpose of this study is to assess the performance and safety for the use of the investigational catheter for intracardiac mapping in the atria and ventricles.

Patients 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.

The long-chain n-3 polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), appear to offer protection against sudden cardiac death and ventricular arrhythmias. EPA and DHA are essential fatty acids which are incorporated into cellular membranes after regular ingestion of fatty fish or fish oil. This study investigates a possible acute effect of intravenous infusion of n-3 PUFA on inducibility of ventricular tachycardia (VT) in patients with an ICD-pacemaker. The hypothesis is that an acute rise in the concentration of n-3 PUFA in plasma will increase the electric stability of the myocardial cells, so that VT is more difficult to induce. In a randomized, placebo-controlled, double-blind, crossover study, a lipid emulsion with a high content of n-3 PUFA (or placebo: isotonic saline) will be administered intravenously before a non-invasive electrophysiologic examination performed via the ICD and following a predefined protocol. The main outcome is inducibility of VT. If sustained VT is induced in a patient after both n-3 PUFA and placebo, the strength of the required stimulus after n-3 PUFA and after placebo is compared.

The completed MADIT II study has shown that implantation of a cardioverter-defibrillator (ICD) in patients with a reduced left ventricular ejection fraction and a prior myocardial infarction reduces death from any cause. The probability of the first therapy due to ventricular tachyarrhythmia was about 34% within 3 years. With a 3-month ICD-follow-up scheme, as it is in the standard ICD therapy, the majority of patients is followed more closely than necessary with respect to anti-tachyarrhythmia ICD therapy. A Home Monitoring (HM) function has been integrated into several ICD models from Biotronik (Berlin , Germany), for close remote monitoring of ICD patients. The HM function may substitute in-clinic follow-up controls. The objective of our study is to compare a standard 3-month follow-up scheme and a 12-month follow-up scheme using HM in ICD recipients with the "MADIT II indications". The comparison should be made with respect to the difference in follow-up burden and the associated costs, and regarding possible impact of the remote follow-up via HM on all cause mortality, hospitalization, and patients' quality of life.

The purpose of this study is to assess the performance and safety for the use of the OPTRELL Catheter for intracardiac mapping in the atria and ventricles.

The purpose of this study is to evaluate the effects that electromagnetic field exposure from using a tablet and smart phone have on a leadless pacemaker (MICRA device).

The primary objective of this study is to assess the effect of an energy drink on ventricular repolarization as measured by the interval between the cardiac Q wave and the cardiac T wave (QT interval)obtained from the body surface ECG. The secondary objective is to assess the effects of an energy drink on heart rate and blood pressure (hemodynamic effects). To place the observed changes in context, comparison will be made to a commonly consumed drink, coffee: Starbuck's K-cup Breakfast Blend.

Patients with Postural Tachycardia Syndrome (POTS) may not adequately expand their plasma volume in response to a high sodium diet. Mechanisms involved in the regulation of plasma volume, such as the renin-angiotensin-aldosterone system and renal dopamine (DA), may be impaired in POTS and may respond inappropriately to changes in dietary sodium. The investigators propose that the changes in urinary sodium and dopamine excretion caused by consuming low-sodium and high-sodium diets will be different between patients with POTS and healthy volunteers. The purpose of this study is to determine (1) whether changes in dietary sodium level appropriately influence sodium excretion in POTS; (2) whether changes in dietary sodium level appropriately influence DA excretion in POTS; (3) whether a high dietary sodium level appropriately expands plasma volume in POTS; and (4) whether patients with POTS have improvements in their orthostatic tachycardia and symptoms as a result of a high dietary sodium level.