Investigation Of Sudden Cardiac Death In The Young
Funder
National Health and Medical Research Council
Funding Amount
$682,823.00
Summary
Sudden cardiac death is a major tragedy in young people. In approximately one third of such cases, no cause of death is found at autopsy. This study will investigate the causes of sudden cardiac death in the young, with a specific emphasis on the underlying genetic causes of sudden unexplained death. This information will be used for screening surviving family relatives, thereby improving both diagnostic and treatment-prevention opportunities and reducing sudden cardiac death in our community.
Cardiac Arrhythmias And Cardiac Contractility During Stress: Regulation By Brainstem Medullary Raph Neurons
Funder
National Health and Medical Research Council
Funding Amount
$425,250.00
Summary
Life is stressful, and in subjects with predisposed hearts stressful events may provoke sudden life-threatening or fatal disturbances of the heart rhythm (arrhythmias). Activity in nerves that control the heart is the main trigger of arrhythmias. This activity is initiated in the brain, when, for example, we have a sudden emotional shock. At present, the neurochemistry and connections of the brain neurons responsible for arrhythmias, have not been identified. Our project is designed to find answ ....Life is stressful, and in subjects with predisposed hearts stressful events may provoke sudden life-threatening or fatal disturbances of the heart rhythm (arrhythmias). Activity in nerves that control the heart is the main trigger of arrhythmias. This activity is initiated in the brain, when, for example, we have a sudden emotional shock. At present, the neurochemistry and connections of the brain neurons responsible for arrhythmias, have not been identified. Our project is designed to find answers to these questions. Our hypothesis is that the responsible neurons are located in the midline portion of the medulla oblongata (the lower part of the brain); that activation of these neurons will increase cardiac function in a manner that may provoke arrhythmias; and, conversely, that their inhibition will protect the heart during stressful events by suppressing potentially arrhythmogenic neural signals. We hypothesise that cardiac-controlling neurons possess receptors for serotonin (one of the brain neurotransmitters), and that the neurons can be inhibited by drugs that selectively activate a specific subtype of these receptors. Our results will increase our understanding of the causes of cardiac arrhythmias by elucidating the link between emotional-psychological events in the brain and stress-induced cardiac events. Our findings could contribute to the identification of new drugs that will protect the heart during stress.Read moreRead less
Disturbances to the normal rhythm of the heart beat cause ~15% of deaths in our community. We wish to understand why the electrical signals in the heart can become chaotic. We will study a particular heart rhythm disturbance called acquired long QT syndrome to see if it is possible to develop a computer model that can accurately predict when and how arrhythmias will occur.
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
Evaluating The Potential Of HERG Channel Agonists As Mechanistically Targeted Antiarrhythmics
Funder
National Health and Medical Research Council
Funding Amount
$414,786.00
Summary
Abnormal heart rhythms cause ~10 % of deaths in the western world and this number is increasing. To date there has been little success in identifying drugs that are effective in treating these disorders. By studying a rhythm disturbance called long QT syndrome we will examine whether specifically targeting drugs to the molecular building blocks of these arrhythmias is an appropriate route for development of more effective drugs.