The team at Melbourne Heart Rhythm is world renowned for producing novel and award-winning research. We have an excellent doctoral (PhD) program affiliated with the University of Melbourne with a team of enthusiastic and dedicated young researchers. You may have the opportunity to be involved in one of our research project and meet some of our PhD fellows during the course of your treatment. Below is a sample of the exciting research that we are undertaking at Melbourne Heart Rhythm. If you are interested in becoming involved with some of our research please contact us and our helpful research team will discuss this with you in more detail.
We have an international reputation of excellence in both clinical and mechanistic arrhythmia research in both Atrial Fibrillation and Ventricular Tachycardia. Our research into electrical remodelling of the atrium in a range of conditions which lead to the development of atrial arrhythmias, including congestive cardiac failure, sinus node dysfunction and congenital heart disease has been published in leading international journals and has been referenced by other leading researchers.
One of our main research focuses has been to try and understand the underlying mechanism of persistent atrial fibrillation in humans. We are developing a technique to map AF in 'real-time' which will hopefully help us treat patients with this condition. Indeed, this is an exciting time for the field of electrophysiology as we are now able to intergrate electrical data obtained during human mapping with structural information obtained from CT and MRI. These technological advances will allow us to understand the complex interplay between between electrophysiology and three dimensional anatomy.
Not only are we interested in mechanistic research, we are also involved in a wide range of clinical trials and clinical research in the areas of Atrial Fibrillation treatment, Atrial Fibrillation Ablation, Atrial Fibrillation and Heart Failure, Sudden Cardiac Death in patients with Renal Dysfunction and the assesment of Novel Mapping and Ablation technologies.
Our Current Research Projects:
Mapping of Atrial Arrhythmias using High Spatial Resolution Mapping Catheters and the Rhythmia 3D Mapping System
During a catheter ablation procedure a specialized mapping catheter and a three-dimensional computer mapping system is routinely used to record the abnormal electrical signals in the heart to locate the focus or circuit that is causing the abnormal heart rhythm.
Recently, a new three-dimensional computer mapping system called Rhythmia (Boston Scientific) and new specialized mapping catheters (IntellaTip-MiFi and IntellaMap-Orion) have become available for clinical use. The fundamental advantage of the new mapping catheters is that they have a much higher spatial resolution and more recording electrodes than currently available mapping catheters. In addition, the new computer mapping system has specialized software that automatically analyzes and processes the electrical data to create highly detailed three-dimensional electrical maps of the heart. We predict that this new technology will result in more accurate electrical maps of the heart and help us better understand and treat abnormal heart rhythms.
The purpose of this research study is to determine the resolution and accuracy of these new mapping catheters (IntellaTip-MiFi and IntellaMap-Orion) and computer mapping system (Rhythmia) in the treatment of atrial arrhythmias.
Epicardial Mapping of Human Atrial Fibrillation
In this study we have aimed to characterize the precise nature of atrial activation in human persistent AF, through high-density recording of electrical signals from the outer surface of the heart during elective cardiac surgical procedures, followed by dynamic wavefront mapping. In preliminary findings we have observed a high degree of spatiotemporal stability of AF activation patterns and of the cycle length of atrial activation, we have demonstrated that short cycle length activity is overwhelmingly due to passive wavefront collision rather than representing active drivers of the fibrillatory process, but we have demonstrated a high prevalence of transient reentry circuits centered on locations of high frequency activity and consistent with the rotors described in early reports by other research groups.
Global Left Atrial Mapping In Human AF
In this study we have been exploring the use of multi-electrode basket catheters for recording of electrical signals from the interior surface of the left atrium prior to catheter ablation procedures in human paroxysmal and persistent AF. Such technology has been used by a research group in the USA to demonstrate a high prevalence of spatiotemporally stable rotors as active drivers of the fibrillatory process. Our preliminary data suggests that these spherical basket catheters allow imperfect global recording and lack the spatial detail provided by epicardial mapping. Whilst gross activation patterns, such as activity emanating from the pulmonary veins during paroxysmal AF, can be demonstrated, we have not reliably identified stable drivers in human persistent AF.
Progressive Left Atrial Remodelling In Human AF
In this study we have used transthoracic echocardiography to measure left atrial strain, as a putative marker of left atrial remodeling and fibrosis. Over 12 months we have performed serial echocardiograms in cohorts of patients with paroxysmal and persistent AF undergoing medical management, in patients with AF undergoing AF ablation, and in a control cohort with no history of AF. We have also performed serial electrocardiographs to measure P-wave duration and dispersion. First, we have demonstrated that left atrial strain parameters do reflect the extent of remodeling as measured through invasive electro-anatomic mapping. As has been demonstrated previously, we have shown reversal in the extent of remodeling after effective catheter ablation. In preliminary data a new finding is that, in the absence of AF ablation and with with ongoing AF, there is progressive remodeling that appears to be in proportion to the burden of arrhythmia. This suggests that the arrhythmia itself is a key driver of pro0gressive atrial disease in human AF.
Predictors Of Symptom Severity In Human AF
In this study we have been exploring factors that underlying the severity of the patient experience of AF. In preliminary data the central finding is that personality style, and particularly a personality marked by vulnerability to stress and by negativity, along with the presence of psychological distress comprised of symptoms of anxiety and depression, is the central driver of symptom severity and of impairment in quality if life. Clinical variables including weight, age and female gender also play a role. Importantly, the objective burden of AF as measured by implanted recorders also appears to be a key factor, something which has not previously been demonstrated.
Identification and Characterisation of Risk Factors for Atrial and Ventricular Arrhythmias in Chronic Kidney Disease (CKD) Patients Using the Implantable Loop Recorder.
This study aims to investigate the underlying mechanisms of lethal cardiac arrhythmias in CKD patients undergoing haemodialysis who experience sudden cardiac death by evaluating the long term incidence/spectrum of arrhythmias and determining the mode of sudden cardiac death. Potential high risk predictors including autonomic tone, ventricular repolarisation and corrected QT interval will also be assessed.
Cardiac Arrhythmias in Sudden Unexplained Death in Epilepsy (SUDEP)
Patients with severe refractory epilepsy are known to be at increased risk of sudden death. The mechanisms of sudden cardiac death in these patients is unknown but it is postulated that it may be related to central nervous system over stimulation of the heart resulting in life-threatening cardiac arrhythmias. This study seeks to determine the link between SUDEP and cardiac arrhythmias.
CAMERA-MRI is a prospective multi-centre cardiac MRI guided randomised controlled trial investigating the role of AF ablation in patients with persistent or long standing persistent AF and otherwise unexplained LV dysfunction. It includes the 'AF Substrate in Heart Failure Sub-study" evaluating the electrophysiological characteristics of the atria in the setting of AF and LV dysfunction.
Cardiac Resynchronization Therapy (CRT) And AV Node Ablation Trial in AF (CAAN-AF)
The purpose of this research study is to investigate whether there are beneficial effects related to AV Node ablation compared with rate control drugs, for people with heart failure and AF who currently have or are eligible for a CRT device. Your doctor has approached you about this study because you have been diagnosed with cardiomyopathy and are suffering from AF and heart failure.
Catheter Ablation versus Antiarrhythmic Drug Therapy for Atrial Fibrillation (CABANA)
This CABANA study aims to investigate the beneficial effects of a therapy with standard anti-arrhythmic drugs compared with the beneficial effects of catheter ablation in patients with atrial fibrillation. This study has been designed to assess which therapeutic approach is better and under which circumstances one or the other type of therapy would be preferable. This scientific study also compares the treatment costs of the two procedures and determines the effects these treatment methods have on quality of life.