Active clinical trials for "Tachycardia, Ventricular"

Ventricular tachycardia is one of the commonest cause of sudden death in chronic chagas disease. As most ventricular tachycardias originate from scar in patients with heart disease, catheter ablation is an important step in patient treatment. Identification of fibrosis prior to ablation of sustained ventricular tachycardia (SVT) might reduce the time of anesthesia, procedure time, radiation exposure and possibly the risk of complications. Knowledge of arrhythmia circuit within scar allows planning strategies for each procedure. Condreanu et al. stablished that voltages inferior to 6.52 mV (unipolar) and 1.54mV (bipolar) are useful tools in detecting scar during electroanatomic mapping. Accuracy, however when compared to magnetic resonance imaging is limited due to difficulties in maintaining good contact between ablation catheter and ventricular wall. Contact force catheters might help increase accuracy of voltage mapping because they allow detection of poor contact areas. Although the threshold for identification of scar in ischemic and non ischemic patients during electroanatomical mapping is already known, this parameters still lacking for chronic chagasic individuals. A marked qualitative histological difference between these fibrous scars supports the hypothesis that voltage scar in chagasics might be different. Catheter ablation contact with endo and epicardial surface is an important issue when ablating arrhythmias. Conventional catheter ablation is not equipped with sensors capable of detecting degree of contact with the target. To our knowledge, the literature lacks information in regard to late lesions produced by a known contact force pressure "in vivo". The pattern of electrical activation in these patients and their relationship with local coronary veins for resynchronization likely to approach through the coronary sinus can be useful in defining chagasic that can benefit from resynchronization. Compare endocardial and epicardial impedance and voltage using CARTO 3 with fibrosis on 3T MRI Correlate areas of late activation within scar during activating mapping in sinus rhythm with different signal intensity in 3T MRI Evaluate the influence of contact pressure during application of radiofrequency in making fibrosis analyzed 30 days after the procedure using a 3T MRI. Assess the site of latest left ventricular activation in sinus rhythm and correlate with the coronary veins location

Time-limited adaptive responses of thyroid function are common in the critically ill. About 70% of all patients treated on intensive care units develop a so-called non-thyroidal illness syndrome (NTIS) or TACITUS (thyroid allostasis in critical illness, tumours, uraemia and starvation), which is marked by low serum concentrations of the thyroid hormone T3 and other adaptive reactions of thyroid homeostasis. Occasionally, temporarily elevated concentrations of thyrotropin (TSH) and peripheral thyroid hormones are to be observed, especially after cardiopulmonary resuscitation (CPR). However, the available evidence is limited, although abnormal concentrations of thyroid hormones after CPR have occasionally been reported. Aim of the planned study is to investigate the thyrotropic (i.e. thyroid-controlling) partial function of the anterior pituitary lobe immediately after CPR. It is intended to evaluate statistical measures of TSH concentration and peripheral thyroid hormones in de-identified datasets (protocol A). Additionally, a prospective sub-study (protocol B) aims at a more precise description of pituitary and thyroid responses by means of serial investigations in routine serum samples, both immediately after CPR and during the course of ongoing treatment. This includes the evaluation of additional possible predictors, too. Primary endpoint of the study is changed TSH concentration immediately after CPR compared to the TSH value 24 hours later. Secondary endpoint is the relation between thyroid-controlling pituitary function and mortality. A high proportion of patients undergoing CPR will eventually receive iodinated radiocontrast media (e.g. for computed tomography or coronary angiography). This is one of the reasons why early identifying subjects at high risk for possible iodine-induced thyrotoxicosis is important. Increased oxygen consumption of the heart in hyperthyroidism is one of the reasons for high mortality in thyrotoxicosis. Therefore, accurate diagnosis of alterations in the hypothalamus-pituitary-thyroid (HPT) axis is of paramount importance.

Arrhythmogenic Cardiomyopathy (ACM) is increasingly identified as an important cause of cardiac morbidity and mortality, especially of SCD, in a younger population. Although there are no epidemiological data available, the investigators' experience is that in the North Indian region, ACM is rare outside our regions. ACM is also an understudied cardiac disorder in the South-Asian region. An ethnic nonmigratory population inhabits the two regions, and consanguineous marriages are common. Based on these observations, the investigators firmly believe that there may be a founder gene in our populations responsible for the increased incidence of ACM. Our project includes a thorough phenotypic analysis ((ECG, Holter, and echocardiography) in the ACM patients and their first-degree relatives; cardiac MRI and high resolution endocardial bipolar and unipolar voltage mapping (using HD grid catheter) in the patients. The patient provided blood for the extraction of DNA will first undergo target panel sequencing for 20 known classic right-dominant ACM and left-dominant ACM. If this is negative for known pathogenic and likely pathogenic variants but identified novel variants of uncertain significance (VUS), then co-segregation analysis in family members will be performed. This technique can provide helpful information to reclassify VUSs. If both these are negative, then whole-exome 'trio' analysis will be performed, whch includes the proband and two family members, to triangulate from all 20,000 genes to a list of candidates for further interrogation. The investigators wish to provide comprehensive answers to the research question by combining the genetic analysis with phenotypic evaluation.

This study aims to evaluate the electrophysiological properties of the heart conduction system in patients with unexplained polymorphic ventricular tachycardia (VT) and/or ventricular fibrillation (VF), in patients with specific genetic mutations regarding sudden cardiac death or sudden cardiac arrest, in their family members and in a control cohort. The electrophysiological properties will be measured with the relatively new technique ECG-Imaging (ECGI). Also a National Dutch registry for patients with unexplained polymorphic VT and/or VF and their family members will be created. By combining the data from the registry and the results of ECGI, The investigators hope to identity risk markers for patients at higher risk for apparently idiopathic ventricular fibrillation, and use these for an adapted flow chart for the 'general'population of patients at risk for unexplained polymorphic VT and/or VF. The investigators aim to be able to identify patients before the first arrhythmic event, and aim for better treatment strategies in the future.

The "Registry of Malignant Arrhythmias and Sudden Cardiac Death - Influence of Diagnostics and Interventions (RACE-IT)" represents a mono-centric registry of patients being hospitalized suffering from malignant arrythmias (ventricular tachycardia or fibrillation) and sudden cardiac death (SCD). Detailed findings of patients' clinical outcome regarding mortality and co-morbidities related to the presence of invasive diagnostics or therapies including coronary angiography, percutaneous coronary intervention (PCI), electrophysiological testing (EP), catheter ablation and implanted cardiac devices (e.g. implantable cardioverter-defibrillators) will be documented. Patients will be included when being hospitalized from the year 2004 until today.

Background: The wearable cardioverter defibrillator (WCD) is an established treatment option for patients at high risk for ventricular tachycardia / ventricular fibrillation (VT/VF), either in whom this risk may only be temporarily present, or in patients at high risk for sudden cardiac death (SCD) or after VT/VF in whom an implantable cardioverter defibrillator (ICD is currently not possible for other reasons (infection, recent MI <40days, recent PCI/CABG < 3months etc.). Methods: Comprehensive registry including all patients in Austria who received a WCD in 2010-2016.

High-resolution, non-invasive electromechanical mapping in genotyped long-QT syndrome patients and healthy controls at baseline and during smart provocation.

Sudden cardiac death is a frequent cause of cardiovascular mortality. Numerous rhythmic risk assessment criterion have been described targeting the substratum, the cardiac nervous tone or the trigger of arrhythmias. Development of ventricular tachycardia ablation in the past few years show interesting results preventing the recurrence of ventricular arrhythmias.

The primary hypothesis is that an ICD shock may be predicted days in advance by a combined score derived from different data obtainable from the ICD

Background: Patients at increased risk for sudden cardiac death (SCD) may receive an implantable cardioverter defibrillator (ICD). The primary criterion for a primary prevention ICD implantation is a left ventricular ejection fraction (LVEF) below 35%, but refinement of ICD criteria is important since only a small proportion of ICD patients receives appropriate device therapy (ATP or a shock) during follow-up. Post-extrasystolic potentiation (PESP) may be a new risk marker for SCD. PESP is defined as a temporary increase in contractility that follows an extrasystolic beat (ESB) and is associated with myocardial calcium handling. In heart failure, changes in calcium homeostasis may lead to afterdepolarisations and thus predispose for SCD. PESP can be measured indirectly and non-invasively as post-extrasystolic blood pressure potentiation (PESP-BP). Abnormal PESP-BP was previously found to be an independent predictor of increased mortality in post-myocardial infarction patients with a reduced LVEF. However, it is unknown if this increased mortality in heart failure patients with abnormal PESP-BP is caused by an increased risk of SCD. Hypothesis: The investigators hypothesize that PESP-BP might be a new predictor of the occurrence of SCD, and can be used to enhance patient selection for primary prevention ICD therapy. Design: During scheduled device replacement ESB with various extrasystolic and post-extrasystolic coupling intervals will be evoked by electrical stimulation via the right atrial and ventricular device leads of the patient. Throughout the stimulation study blood pressure will be measured non-invasively a continuous electrocardiogram will be recorded. Either before or after the procedure, patients will undergo a 30-minutes assessment of spontaneous ESB, again with blood pressure and ECG recordings. Study population: 30 patients who are scheduled for device replacement or reposition, are eligible for this study; (1) 10 ICD patients who previously received appropriate device therapy (ADT); (2) 10 ICD patients who are free from ADT and (3) 10 dual-chamber pacemaker patients (control group). Outcomes: (1) Evoked PESP-BP (i.e. blood pressure differences between baseline, ESB and post-ESB); (2) Spontaneous PESP-BP (i.e. blood pressure differences between baseline, ESB and post-ESB); (3) Timing parameters (in ms): the basic cycle length interval; Extra-systolic interval (ESI); Post-extrasystolic interval (PESI).