Development Of Endpoints For Catheter Ablation Of Non-mappable Scar-related Ventricular Tachycardia.
Funder
National Health and Medical Research Council
Funding Amount
$176,686.00
Summary
Ventricular tachycardia is a dangerous heart rhythm disturbance that affects people with scarring in the heart such as those with prior heart attacks or heart failure. Catheter ablation procedures, using wires passed from the groin, can be used to burn the short-circuits related to the scar. However in the majority of cases, it is very difficult to know when enough burning has been performed. This project aims to develop and validate several electrical and imaging endpoints for this procedure.
Renal Sympathetic Denervation As An Adjunct To Catheter-based Ventricular Tachycardia Abaltion
Funder
National Health and Medical Research Council
Funding Amount
$188,226.00
Summary
The most common cause of sudden death is lethal heart rhythms. Despite medications and medical procedures, many patients still suffer from these life-threatening rhythms. Treatment of the nerves around the kidneys may alter the production of hormones that contribute to these rhythms which could have a significant impact on these patients.
Utility Of Direct Endocardial Visualisation To Characterise Scar Morphology And Ablation Lesion Formation
Funder
National Health and Medical Research Council
Funding Amount
$421,285.00
Summary
Endocardial visualisation is a new technique in which a catheter is used to look at the internal surface of the heart without the need for surgery. We will use the visualisation catheter to find a better way of placing small burns within the heart to stop atrial fibrillation (one of the most common heart diseases). We will also use the visualisation catheter to find a better way of locating the scarred areas of the heart responsible for ventricular tachycardia (another common heart disease).
Validation Of Noncontact Mapping And Evaluation Of Catheter Intramural Ablation For Ventricular Tachycardia
Funder
National Health and Medical Research Council
Funding Amount
$252,780.00
Summary
Sudden death is the most common mode of death in patients who have had scarring in their hearts due to a heart attack. Sudden death is usually caused by a very rapid, abnormal heart rhythm called ventricular tachycardia. The most effective treatment is the implantation of a device called an implantable defibrillator. These devices are only palliative and are very expensive. Each device costs $15,000 - $30,000 and the cost of treating a patient during his-her lifetime could be as much as $150,000 ....Sudden death is the most common mode of death in patients who have had scarring in their hearts due to a heart attack. Sudden death is usually caused by a very rapid, abnormal heart rhythm called ventricular tachycardia. The most effective treatment is the implantation of a device called an implantable defibrillator. These devices are only palliative and are very expensive. Each device costs $15,000 - $30,000 and the cost of treating a patient during his-her lifetime could be as much as $150,000. New methods need to be developed to eradicate these abnormal rhythms completely. Ventricular tachycardia is usually due to reentrant electrical circuits deep within the heart muscle. The project aims to develop and evaluate a non-operative technique to eradicate these abnormal electrical circuits. Noncontact mapping is a promising new technology capable of detecting electrical signals from multiple sites in the heart simultaneously. This project aims to validate this technology using the gold-standard contact mapping. We have already developed two prototypes of catheters that will be evaluated in sheep and developed further. These catheters are specially designed to introduce a needle into the heart muscle to perform radiofrequency ablation. Radiofrequency ablation is a technique of destroying, in a well-controlled manner, a small area of heart muscle. If this technique is found to be successful, it might cure ventricular tachycardia in some patients or eradicate the most troublesome reentrant circuits in other patients. It is likely to negate the need for implantable defibrillator in a significant number of patients, resulting in a tremendous saving in health care costs. Patients who have the procedure after already having an implantable defibrillator will benefit from increased longevity of their device because of eradication of the most troublesome reentrant circuits.Read moreRead less
Longitudinal Mechanics Of The Peri-Infarct Zone And Ventricular Tachycardia Inducibility In Patients With Chronic Ischaemic Cardiomyopathy
Funder
National Health and Medical Research Council
Funding Amount
$438,449.00
Summary
Ischaemic heart disease is a major cause of death in developed countries. Sudden cardiac death is precipitated by lethal irregularities in heart rhythm that originate around the scar tissue that forms within the heart after a heart attack. This study�s aim is to investigate the role of new ultrasound technologies in characterising the heart tissue where fatal cardiac arrhythmias arise. We hope that these novel imaging tools will help to identify individuals whose lives may be saved by appropriat ....Ischaemic heart disease is a major cause of death in developed countries. Sudden cardiac death is precipitated by lethal irregularities in heart rhythm that originate around the scar tissue that forms within the heart after a heart attack. This study�s aim is to investigate the role of new ultrasound technologies in characterising the heart tissue where fatal cardiac arrhythmias arise. We hope that these novel imaging tools will help to identify individuals whose lives may be saved by appropriate preventative measures.Read moreRead less
Role Of Non-Invasive Imaging Using Speckle Tracking Echocardiography In The Identification And Treatment Of Patients At Risk Of Arrhythmias And Consequent Sudden Cardiac Arrest
Funder
National Health and Medical Research Council
Funding Amount
$437,034.00
Summary
Every year, 15,000 Australians die from sudden cardiac arrest. Identifying individuals at risk is a major challenge. We will investigate whether a heart ultrasound technique called speckle tracking allows clinicians to rapidly identify changes in heart muscle that are associated with cardiac arrest. If found to be positive, the technique may be broadly applied to large populations, identifying at risk individuals, potentially rescuing them before cardiac arrest occurs.
Improved electrophysiological mapping techniques have enhanced understanding of arrhythmia mechanisms and the development of curative ablation strategies. Advanced mapping systems utilize online visualization of catheters, 3D geometry, and annotation of ablation sites. To date, all commercially available systems rely on proprietary equipment to locate catheter positions and reconstruct chamber shape from multiple site recordings. Thus, cost is prohibitive, limiting widespread availability. An al ....Improved electrophysiological mapping techniques have enhanced understanding of arrhythmia mechanisms and the development of curative ablation strategies. Advanced mapping systems utilize online visualization of catheters, 3D geometry, and annotation of ablation sites. To date, all commercially available systems rely on proprietary equipment to locate catheter positions and reconstruct chamber shape from multiple site recordings. Thus, cost is prohibitive, limiting widespread availability. An alternative approach has emerged with the use of CT-MRI imaging and analysis. Novel techniques extract images of the endocardial surface from CT-MRI for use in electrophysiological mapping. This surface can be used as the chamber geometry instead of reconstruction based on expensive technology measuring spatial coordinates of the catheter tip inside heart. The proposed Anatomical Template Mapping System (ATMS) will generate maps of electrophysiological parameters derived from catheter recordings without the need for proprietary equipment. The physician will direct the virtual catheter position onto the 3D model of the chamber, obviating the need for equipment to map the spatial distribution of the catheters. The major advantage is that, without the need for specialized equipment, this method of mapping is substantially cheaper and can be used with any conventional electrophysiological mapping systems. Furthermore, it will provide the most important feature of the advanced mapping systems - an understanding of the arrhythmia mechanism.Read moreRead less
Substrate Mapping And Ablation Of Ventricular Tachycardia
Funder
National Health and Medical Research Council
Funding Amount
$444,129.00
Summary
Sudden death is a tragic occurrence and can afflict Australians of all ages, racial and ethnic backgrounds. This research will aim to understand abnormalities in the heart muscle that cause dangerous heart rhythm abnormalities, which is the most common cause of sudden death. We will study ways to improve the technology of keyhole cardiac procedures so that it can be used to prevent these arrhythmias from occurring in the first place, and in improving the chance of long-term successful cure.
Electrophysiologic Properties Of The Ventricular Myocardium Promoting Reentry
Funder
National Health and Medical Research Council
Funding Amount
$272,871.00
Summary
Ventricular tachycardia is a dangerous heart rhythm that usually occurs in people with prior heart attacks. These people often have scarring on their heart and the tachycardia occurs due to electrical activity forming a circuit around the scar. This study will examine the factors that cause ventricular tachycardia to begin by looking at the characteristics of the scarring.
Noncontact Biventricular Mapping And Intramural Ablation In A Chronic Ovine Model Of Septal Ventricular Tachycardia
Funder
National Health and Medical Research Council
Funding Amount
$519,279.00
Summary
Ventricular tachycardia (VT), an abnormal rhythm originating from the bottom portion of the heart is the major cause of sudden death in the community. Medications are not reliably effective. Expensive (costing about $40,000 every 5 years) implanted defibrillators are very effective in terminating VT, but frequently require painful shocks. Patients who require frequent treatment from their defibrillators are considered for mapping and ablation. About half of the patients with VT have the arrhythm ....Ventricular tachycardia (VT), an abnormal rhythm originating from the bottom portion of the heart is the major cause of sudden death in the community. Medications are not reliably effective. Expensive (costing about $40,000 every 5 years) implanted defibrillators are very effective in terminating VT, but frequently require painful shocks. Patients who require frequent treatment from their defibrillators are considered for mapping and ablation. About half of the patients with VT have the arrhythmia originating from the septum (heart muscle separating the two bottom portions of the heart). This area of the heart is difficult to map from an electrical point of view. A new type of mapping system called the Ensite 3000 system enables acquisition of 3,300 virtual electrical signals from within a heart chamber using an electrode array that does not have to be in direct contact with the heart muscle surface. Our evaluation of the Ensite system in one chamber of the heart has found it to be very good in identifying areas of abnormal electrical activity. It is possible that simultaneous mapping from both sides of the septum using Ensite might be useful in mapping VT originating from the septum. Destruction of the abnormal area, once identified, is generally done using a catheter, but is limited by its ability to destroy targets deep in the heart tissue. We have designed and developed a catheter that is equipped with a needle at its tip that can create deeper lesions. In this study we will be evaluating mapping using the Ensite electrodes in both ventricles in a chronic sheep model with VT originating from the septum. The Ensite mapping will be validated with detailed contact (conventional) mapping. The prototype catheter will be used to destroy the site of origin of VT, once identified. This study should enable more effective treatment of patients with VT and improve their quality of life.Read moreRead less