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Associate Professor Raymond Sy

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Associate Professor Raymond Sy

Assessing the effect of quinidine in brugada syndrome

Associate Professor Raymond Sy, University of Sydney

2019 Vanguard Grant

Years funded: 2020-2022

Brugada Syndrome (BrS) is an inherited heart disease that can cause irregular heart rhythms (arrhythmias) and sudden cardiac death. It accounts for 20% of sudden cardiac deaths in young people whose hearts appear normal at autopsy. Despite being described nearly 30 years ago, BrS remains poorly understood and treatment options are limited. Currently, the only treatment to reduce the risk of sudden death in BrS is the implantation of a cardiac defibrillator. Although lifesaving in the event of dangerous arrhythmias, defibrillators do not prevent irregular heart rhythms and carry risks ranging from the psychological trauma of receiving a shock while conscious, to life threatening infections. As a result, implantable defibrillators are only recommended in patients with prior cardiac arrest, ventricular fibrillation or syncope. This leaves the majority of patients with BrS, who are asymptomatic, without protection.

Quinidine is the only medication that has been shown to be effective in BrS. It reduces the risk of arrhythmia in asymptomatic patients and the burden of arrhythmias in symptomatic patients. An electrophysiology study is an invasive procedure which tests the electrical activity of the heart by placing wires inside the heart via veins in the leg. Currently, this is the only way known to monitor the efficacy of Quinidine in BrS. In the QUIET BrS Study, we will assess the feasibility of using & non-invasive & tests to evaluate the efficacy of Quinidine therapy in BrS. We will investigate potential makers of response to therapy with investigations such as electrocardiogram and 24-hour Holter monitoring. We will also evaluate the application of a novel, non-invasive surrogate for electrophysiological studies in our cohort. This pilot data will underpin future larger studies to better identify those who may benefit from Quinidine therapy, monitor its efficacy non-invasively and ultimately improve the care of patients with BrS and reduce sudden deaths.

Last updated12 July 2021