Active clinical trials for "Tachycardia, Ventricular"

This study will test the hypothesis that many human heart rhythm disorders are caused by small localized sources, where brief ablation may successfully eliminate the heart rhythm disorder.

The purpose of the study is to evaluate the safety and efficacy of wearable defibrillator use in patients with left ventricular dysfunction or advanced heart failure symptoms, who have a high-risk for sudden cardiac death but are either not eligible for an implantable defibrillator under current guidelines or are not able to receive the device due to their condition.

Risk prediction in in inherited heart rhythm conditions that may cause sudden cardiac arrest or death is difficult. Sometimes the risks may be low but the loss of life in an otherwise healthy young individual is catastrophic. Clinicians often treat to the extreme to prevent this and so often those at unknown risk for a serious cardiac event are treated with an implanted cardioverter defibrillator (ICD) to protect against sudden death even though the risk is low or unknown. ICDs them selves are not without adverse events such as needing battery replacements, mechanical complications, inappropriate shocks and body image and self esteem issues for the patient. This study will use an inject able monitor that is less invasive to monitor inherited heart rhythm patients long term to help gather long term heart rhythm data (3 years) on patients with an inherited heart rhythm that will help to detect symptoms of dangerous heart rhythms so that the appropriate care can be provided.

Catheter ablation in patients with ventricular tachycardia using a new mapping algorithm called, parallel mapping, that is aimed to increase the specificity of mapping and the outcome of ablation.

The purpose of this study is to determine whether levels of inflammatory markers in circulating blood can correlate with risk for dangerous heart rhythms. Patients with systolic heart failure, which has been shown to increase risk for dangerous heart rhythms, will be enrolled. All subjects will have an implantable cardioverter-defibrillator (ICD) in place, which allows regular evaluation of heart rhythm.

Implantable cardioverter defibrillators (ICD) may have the capacity to provoke or worsen ventricular tachyarrhythmias (VT). It has been reported that ICD shocks by itself can increase mortality. This study aimed to determine the role of back-up pacing-induced VT (PIT) to the overall ICD shock burden by avoiding pause-related ventricular back-up pacing by programming the pacing output to a sub-threshold level for ineffective pacing.

The Magnetecs Catheter Guidance Control and Imaging (CGCI) system is a magnetic remote navigation system which is comprised of a magnetic chamber of eight electromagnets around the patient torso. The system can change the magnetic field almost instantaneously and enables almost real time manipulation of a special magnetic catheter (Maxwell mapping catheter) which results in accurate, repeatable, rapid and safe target acquisition within the four chambers of the human heart. The trial is a prospective, non-randomized, clinical one designed to test the study hypotheses of (a) technical equivalence of the study device in comparison to other magnetic remote navigation systems, (b) performance equivalence or non-inferiority of the study device target acquisition capability compared to presently used catheter navigation techniques, and (c) safety equivalence or non-inferiority of the study device in comparison to catheter navigation devices using other navigation techniques.

Patients sometimes suffer from life-threatening abnormal heart racing that originates from the lower chamber of the heart. These patients will often need an implantable defibrillator which has the ability to shock the heart back to a normal heart rhythm, but this does not prevent them from getting frequent recurrences of the bad heart rhythm needing shocks from the device. This can be painful and potentially harmful. Medicines to prevent recurrences of shocks are not very effective and have many side effects. An alternative to medicines for this is a procedure called a catheter ablation in which a wire is passed up through the blood vessels of the leg into the heart and used to find the short circuits which cause the dangerous heart rhythm. When the spot causing the trouble is found, the investigators can burn it ("ablate" it). This procedure is challenging and methods are needed to make it more effective and easier to do. One of the main ways for finding the short circuits involves using the electrocardiogram (the "ECG"). The regular ECG is simplistic and only makes use of recordings from 10 sites (6 precordial sites and 4 sites on both upper and lower limbs) on the body surface. The investigators are testing whether making recordings from 120 sites on the chest and back and using special computerized analysis of the recordings can help make catheter ablation for dangerous heart rhythms more effective.

In this study, changes in electroencephalogram (EEG) and the hemodynamic state during ventricular fibrillation or induced ventricular tachycardia are investigated.

This observational protocol will evaluate the effects of monopolar electrocautery (ME) on implantable cardioverter defibrillators (ICDs) in patients undergoing surgery. ME can cause electromagnetic interference (EMI) leading to ICD damage or inadvertent ICD discharge (shocks). Recommended practice calls for the preoperative reprogramming of ICDs when ME will be used to prevent patients from receiving inadvertent shocks. This requires the presence of someone trained in ICD programming, but a trained person is not always readily available. In this study the investigators will reprogram ICDs prior to surgery according to current practice, but will also record what would have happened had the ICD reprogramming not occurred ("detection on" but "therapy off"). In addition, the investigators will evaluate the effect of the location of the electrosurgery unit (ESU) return pad on the incidence of EMI. The investigators hypothesize that directing the current return path away from the ICD will result in lower EMI rates than previously described.