View clinical trials related to Tachycardia.
Filter by:The study evaluates 3 different populations: It is an open, randomized, parallel-group study comparing the effectiveness of intravenous (iv) ajmaline with currently used antiarrhythmic drugs in the acute treatment of : 1. recent-onset atrial fibrillation versus iv flecainide 2. sustained monomorphous ventricular tachycardia versus iv procainamide The study also evaluates in an open, randomized, crossover study, the use of iv ajmaline versus iv flecainide in the diagnosis of Brugada syndrome
Chronic beta-adrenoceptor blockade is known to improve outcome of high risk patients whereas amelioration of autonomic activity was demonstrated to be a major cause of outcome improvement. Therefore, perioperative beta-adrenoceptor blockade is recommended in patients with Revised Cardiac Risk Index score of three or greater. The investigators hypothesise that preoperative intravenous beta-adrenoceptor blockade for treatment of hypertension and/or tachycardia improves autonomic activity reflected by increase of Total Power of Heart Rate Variability. Material and Methods: After IRB approval 20 patients scheduled for elective cardiac surgery were included into the study. Routine medication was continued throughout the study as recommended by the guidelines. HRV (TP and Low to High Frequency ratio (LF/HF) reflecting sympathetic to parasympathetic balance) was analysed prior to induction of general anesthesia and beta-adrenoceptor blockade in all patients (Baseline). Patients were assigned by their baseline hemodynamics. Patients with hypertension (systolic blood pressure > 140mmHg or diastolic blood pressure > 90mmHg) or tachycardia (heart rate > 80bpm) were assigned to group BETA-BLOCK. In this group metoprolol-boli (2mg) were administered intravenously in stepwise manner until hemodynamic values decreased to normal. Total dosage was recorded. After normalisation of hemodynamics, second HRV analysis was performed (Intervention). Normotensive and normocardic patients were assigned to group CONTROL. No intervention was performed. Statistics: Mann Whitney U test for comparison between groups and between events Baseline and Intervention within group BETA-BLOCK, p<0.05.
The purpose of the proposed research is to determine how changes in kidney dopamine (DA) activity influence urinary sodium excretion. We will decrease DA activity in the kidney by inhibiting DA synthesis via carbidopa administration. We want to compare findings in normal volunteers and in patients with postural tachycardia syndrome (POTS). We will test the null hypothesis (Ho) that the effects of oral carbidopa administration on urinary sodium excretion will not differ between patients with POTS and healthy volunteers.
To generate a list of potential genetic markers that correlate with an increased risk of life-threatening arrhythmias. To evaluate ECG-based risk markers such as heart rate variability and T-wave Alternans for their association with arrhythmic events.
In case of sinus node dysfunction, it is often necessary to choose the safer option provided by a DDD pacemaker even though the most appropriate mode of pacing is AAI mode. In addition to saving energy, the latter mode allows spontaneous ventricular activation, the haemodynamic consequences of which are, in most cases, better than those obtained with dual chamber pacing. Recent studies as the MOST study suggest also that ventricular desynchronization imposed by right ventricular apical pacing even when AV synchrony is preserved increases the risk of atrial fibrillation in patients with SND. Similar results were already given by anterior studies (PIPAF) which, taking into account the percentage of ventricular pacing, suggested that AF prevention algorithm in combination with a preserved native conduction are efficient in reducing AF burden. However, current practice is to implant a dual chamber pacemaker to prevent the risk of atrioventricular block (AVB) even if DDDR pacing with a fixed long AV delay was found inefficient in reducing ventricular pacing and was associated with a high risk of arrhythmias. The Symphony 2550 cardiac pacemaker offers pacing modes that automatically switch from AAI(R) mode to DDD(R) or DDI(R) in event of severe atrioventricular conduction disorder, irrespective of whether or not these are accompanied by an atrial arrhythmia, returning spontaneously to AAI(R) mode as soon as the spontaneous AV conduction has resumed. These 2 particular modes are called the AAI SafeR and DDD/AMC (R) mode. The main differences between both modes are that (i) AAI SafeR does not trigger any AV Delay after a sensed or paced atrial event which allows long PR intervals or even limited ventricular pauses with no switch to DDD(R), while (ii) DDD/AMC (R) is able to optimize AV Delay after switching to DDD(R) according to measured spontaneous conduction times and to provide an acceleration in case of vaso-vagal syndrome. This pacing mode has previously been assessed in clinical studies. This study intends to demonstrate that the automatic modes switching significantly reduce the percentage of ventricular pacing in patients implanted with a spontaneous AV conduction and reduce the occurrence of atrial arrhythmias, on a mid-term follow-up period, in comparison to standard DDD pacing with long AVDelay.
- Determine the accuracy of the NTX wireless monitoring system alerts - Evaluate patient compliance with wearing device - Determine false alarm rates
- Reduction in time to detection of Clinically Significant events - Reduction of time to Intervention during Clinically Significant events - Reduction in the number of admissions to Intensive Care
The purpose of this post approval study of heart block is to gather additional information regarding how often patients develop heart block (atrioventricular block) after having standard ablation procedure using cryotherapy with the Freezor™ catheter.
The MADIT-II trial has shown that patients with severely reduced left ventricular ejection fraction (LVEF) post myocardial infarction benefit from the implantable cardioverter-defibrillator (ICD). However, retrospective analyses of the MADIT-II data have revealed a significantly increased morbidity and mortality in patients with appropriate ICD therapy: Appropriate ICD therapy is associated with 3.3-fold increased all-cause mortality, and the risk of a first heart failure hospitalization is 90% higher after 1st appropriate ICD therapy. Hence, the 1st appropriate therapy might indicate the necessity and utility of further clinical diagnostics and therapy in these patients. This trial is designed to (i) improve the knowledge of the group characteristics of patients suffering from 1st appropriate ICD therapy, (ii) but moreover to take additional therapeutic steps to reduce the mortality of this patient population.
The purpose of this study is to determine/identify what mechanisms/factors are involved with regard to AV nodal reentrant tachycardia.