Heart rhythm disorders
Sudden cardiac death (SCD) from ventricular arrhythmias claims over 300,000 lives per year in the U.S. and over 50,000 lives per year in the UK. Despite a recent fall in mortality from cardiovascular disease, the proportion attributed to SCD is increasing. Ventricular tachy arrhythmias are the usual cause, often occurring without warning or provocation most commonly in patients with underlying cardiac disease. Efforts at prediction and prevention therefore have become of major importance in combating this significant public health and socioeconomic problem. The mechanisms of cardiac arrhythmias in a number of conditions including ischaemic heart disease, Brugada syndrome, Arrhythmogenic Right Ventricular Cardiomyopathy and Long QT Syndrome are studied by the Cardiac Electrophysiology Group. The group is focussed on identifying new genes responsible for causing sudden cardiac death, identifying new markers of risk in specific patient groups and optimising prevention & treatment strategies.
Key research activities
- Using Genetics to Understand the Causes of Inherited Arrhythmia Syndromes
Sudden cardiac death under the age of 40 years is due to electrical anomalies in the heart. We screen families with a history of sudden death and look for inheritable causes which can be treated either by drugs or an implantable cardiac defibrillator. We have been investigating the relationship between surface ECG markers that may identify individuals at risk and the genes responsible for these features.
- Understanding the Functional Basis of These Genetic Effects
The electrical behaviour of the heart arising from specific genetic disorders such as Brugada Syndrome and ARVC is of a major focus of our group. Using high density mapping techniques we have been able to characterise the effects of specific gene mutations in patients. New methodologies and the novel use of Bioinformatics are being developed in our laboratory to identify new genes responsible for lethal arrhythmias.
- Cell signalling pathways in cardioprotection
We are currently undertaking an MRC funded study to investigate why electrical instability develops in the heart precipitating cardiac arrest. This involves mapping the surface of the heart and identifying regions of instability to look at differences in local gene expression. This will lead to:(i) a better understanding of the channels and proteins responsible for these instabilities in patients, (ii) providing new drug targets and opportunities to electrically stabilising the heart using novel pacing strategies, (iii) inform us regarding new surface ECG markers of risk & allow us to refine current approaches e.g. T wave alternans analysis.
- In-Vivo and Molecular Investigation of the Arrhythmogenic Mechanisms of Sudden Cardiac Death
Microvolt T-wave alternans is an important clinical marker of arrhythmic risk for sudden cardiac death. Its underlying mechanisms, however, remain unclear. The aim is to fill the void by simultaneously recording the body surface ECG and epicardial electrophysiology during corcordant and discordant alternans in patients classified as microvolt T-wave alternans positive or negative. This work is currently being done by Dr. Xiao Jie, email@example.com