Dopamine in Orthostatic Tolerance
Postural Tachycardia SyndromeOne goal of this study is to determine whether people with different amounts of dopamine-beta-hydroxylase (DBH) have different responses to events that affect blood pressure and heart rate. We will also study whether increasing dietary salt improves symptoms during upright posture. Finally, we will examine whether the dietary sodium level influences serum DBH activity and whether DBH level influences the response to sodium. DBH levels and the function of the sympathetic or involuntary nervous system will be assessed in normal volunteers and in patients with postural tachycardia syndrome (POTS).
Follow-up of Patients With Implantable Cardioverter Defibrillators by Home Monitoring (ANVITE)
Cardiac PacingElectric Countershock1 morePatients with implantable cardioverter defibrillators (ICDs) should undergo regular device follow-ups every 3 months, to verify proper ICD function. However, many follow-ups are uneventful, revealing no relevant changes related to the implanted device and in the patient's diagnostic and therapeutic status. For time and economic reasons, longer follow-up intervals are frequently used although they are not according to recommendations. This may increase the delay in detection of relevant changes in the disease and in deviations from optimal ICD therapy in the individual patients. In the newest ICDs, the essential parameters reflecting safety and appropriateness of ICD therapy (threshold, impedance, intracardiac electrogram, etc.) are transmitted via Home Monitoring on a daily basis, to an internet platform accessible by the attending physician. In the present study, the investigators evaluate safety and efficacy of 12-month follow-up intervals in ICDs with Home Monitoring capability, as compared with conventional 3-month follow-up scheme.
Dipole Density Mapping in Supraventricular Tachycardia
Supraventricular TachycardiaUse of dipole density mapping to identify activation in complex supraventricular tachycardias.
VIVO™ Accuracy Study
Premature Ventricular ContractionVentricular TachycardiaA multi-center study designed to assess the accuracy of VIVO™ in determining the location of a PVC/VT foci in comparison to an electroanatomical mapping system.
A Study to Systematically Assess the Efficacy and Safety of Intravenous Albumin Infusions in Severe...
Postural Orthostatic Tachycardia SyndromePOTS is a relatively common condition that affects millions of patients around the globe. It has an estimated prevalence of 170/100,000 with approximately 80% of patients being women of childbearing age. POTS is characterized by an excessive heart rate increase on assuming an upright posture, either standing or even sitting and leading to disabling palpitations, light-headedness, and even in syncope in severe cases. More than 95% patients with POTS have pronounced cardiovascular deconditioning and show marked exercise intolerance. The severity of POTS is variable. In mild cases the affected patient may continue with routine activities with minimal limitations. Severe form of the disease precludes most normal life activities, such as sitting upright, walking or standing to perform even basic house chores. An estimated 40% of patients with POTS have a resistant form of the condition that is nonresponsive or mildly responsive to all treatments resulting in continued functional limitations in the long term. Many of the currently available treatments in POTS are geared towards increasing blood pressure. These include compression stockings, increased daily fluid intake and increased salt ingestion. Saline infusions may be helpful in certain patients in the short term, though many do not respond. The effectiveness of medications varies greatly, with many patient failing to improve. A small series of clinical patients suffering from severe POTS have shown robust response to weekly albumin therapy, which supports the hypothesis that periodic albumin infusions will provide significant and sustained symptomatic relief to patients with severe POTS. This pilot study will explore the effectiveness of albumin infusions as a treatment for POTS. Eligible patients will receive weekly intravenous infusions of 5% Albumin or Saline in a double blinded fashion for 4 weeks and will crossover to the other infusion for 4 weeks after an intervening 4-week washout period. The participants will be required to maintain a daily diary of their symptoms during the screening, the study and washout periods. Any possible adverse effects as the result of infusions will be documented. Outcome measures will be quantified and validated at the end of each study period and the percentage reduction of tachycardia will be determined at the completion of each study arm.
Stereotactic Non-invasive Ablation of Ventricular Tachycardia
Ventricular TachycardiaSTereotactic Ablative Radiosurgery of recurrent Ventricular Tachycardia in structural heart disease (STAR-VT).
Noninvasive Cardiac Radioablation for Ventricular Tachycardia Refractory to Medication and Catheter...
Ventricular TachycardiaThe purpose of this study is to evaluate the safety and efficacy of cardiac radioablation (CRA) as a means of noninvasive treatment of ventricular tachycardia (VT) refractory to both medication and catheter ablation.
Comparison of Ventricular Tachycardia Ablation Strategies in Patients With Ischemic Cardiomyopathy...
Ventricular TachycardiaThis is a prospective multicenter randomized open-label study aiming to assess whether endocardial or endocardial-epicardial ablation is superior to the standard approach (i.e., Antiarrhythmic drugs) in achievement of long-term ventricular tachycardia (VT) treatment success.
Passive Leg Raising Attenuates and Delays Tourniquet Deflation-induced Hypotension and Tachycardia...
HypotensionTachycardiaBackground: The pneumatic tourniquet is frequently used in total knee arthroplasty. Tourniquet deflation may result in hypotension and tachycardia caused by the rapid shift of blood volume back to the ischemic limb and a decrease in cardiac preload. Passive leg raising (PLR) represents a "self-volume challenge" that can result in an increase in preload. Such a PLR-induced increase in preload was hypothesized to attenuate the decrease in preload resulting from tourniquet deflation. This study was designed to evaluate the effect of PLR on hypotension and tachycardia following tourniquet deflation. Methods: Seventy patients who underwent unilateral total knee arthroplasty were assigned to either the bilateral PLR group (n = 35) or the control group (n = 35), in a prospective randomized trial. The patients' blood pressure and heart rate were measured before, during, and after tourniquet deflation.
Yoga and Rate and Duration of Inappropriate Sinus Tachycardia (IST) Episodes
Inappropriate Sinus TachycardiaInappropriate sinus tachycardia (IST) is an uncommon form of atrial tachycardia. The term "inappropriate" in medicine is commonly defined as a heart rate greater than 100 beats per minute at rest or with minimal physiological challenge. IST is characterized by an increased resting heart rate with an exaggerated response to exercise or stress. Yoga has been used extensively around the world as an alternative medicine approach in treating numerous chronic and debilitating diseases. Studies have been conducted in various countries to determine the benefits of Yoga as therapy for these chronic diseases. Several studies have confirmed that yoga can reduce anxiety and regulate the stress response. Studies in the past have shown that Yoga relieves stress, one of the most common triggers for the arrhythmia and increased heart rate in IST. Based on past studies we hypothesize that patients with IST might benefit by practicing yoga. Yoga may also help in better rate and rhythm control with yoga when employed in combination with usual medical arrangement.