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
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.
Physiological, Biological And Genetic Abnormalitities Associated With The Postural Tachycardia Syndrome
Funder
National Health and Medical Research Council
Funding Amount
$462,290.00
Summary
Postural Orthostatic Tachycardia Syndrome (POTS) is a clinical syndrome characterized by the development of excessive tachycardia (heart rate increases by 30 beats or more per min) when the upright position is assumed. The condition is accompanied by weakness, dizziness, presyncope or fainting. POTS has only recently come to international medical attention as the number of patients with the condition is steadily rising. The symptoms and ongoing disability in POTS appear to primarily result from ....Postural Orthostatic Tachycardia Syndrome (POTS) is a clinical syndrome characterized by the development of excessive tachycardia (heart rate increases by 30 beats or more per min) when the upright position is assumed. The condition is accompanied by weakness, dizziness, presyncope or fainting. POTS has only recently come to international medical attention as the number of patients with the condition is steadily rising. The symptoms and ongoing disability in POTS appear to primarily result from a supernormal reflex sympathetic activation on standing, in ways which are readily apparent for some symptoms, such as tachycardia, but obscure for others, such as postural syncope in the absence of postural hypotension. Poorly defined diagnostic criteria and the likelihood of multiple causes have made it difficult to clarify the underlying pathophysiology of POTS. In this project I will investigate the sympathetic nervous system response to head-up tilt in patients with POTS as well as possible genetic and epigenetic mechanisms which might underpin the syndrome. Preliminary results are encouraging and merit to be taken further.Read moreRead less
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.
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
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).
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.