Cardiac arrhythmias are disturbances in normal heart electrical activity that alter heart rhythm and cause the heart to beat too fast, too slow, or irregularly. Sudden cardiac death (SCD) from lethal ventricular arrhythmias is a leading cause of death, responsible for up to half a million deaths annually in the U.S. and for approximately half of all mortality in patients with heart failure. In fact, the death rate from SCD is higher than that of all cancers combined.1 Establishing an individual’s risk for severe arrhythmias before a life-threatening event occurs is critically important so that appropriate preventive strategies can be implemented. However, this remains a significant medical challenge.
Today’s clinical measures—primarily assessment of cardiac function, electrical activity, and symptoms—help identify heart failure patients who might benefit from implanted device therapies (implantable cardioverter defibrillators (ICD)) for primary prevention. Using these measures, however, less than 25% of patients implanted with an ICD receive appropriate therapy within five years of implant and other patients who might benefit from ICD implant are not currently indicated to receive a device.2 Currently, low left ventricular ejection fraction (LVEF) is the best measure to identify patients who will benefit most from ICD therapies, but improved strategies are needed to better predict disease prognosis, rate of progression, and risk for developing lethal ventricular arrhythmias and SCD.
Genetic susceptibility to sudden arrhythmic death is demonstrated by genetic mutations that cause rare, inherited arrhythmia disorders. In broader populations, further lines of evidence implicate elevated genetic risk among relatives with a positive family history of sudden death.3,4 The aims of our cardiac arrhythmia program are to identify novel genetic and biological markers that are key components in predicting patient risk for lethal ventricular arrhythmias and to develop a test that will aid cardiologists in optimizing the management plan for patients at risk for these events.
- AHA/ACC/HRS Scientific Statement on Non Invasive Risk Stratification Techniques for Identifying Patients at Risk for Sudden Cardiac Death, JACC, Vol 52, 14.
- Bardy GH, Sudden Cardiac Death in Heart Failure Trial Investigators. Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure. Engl J Med. 2005;352:2146.
- Vincent G M, Timothy K W, Leppert M, Keating M. The spectrum of symptoms and QT intervals in carriers of the gene for the long-QT syndrome. N Engl J Med. 1992;327:846–852.
- Jouven X, Desnos M, Guerot C, Ducimetière P. Predicting sudden death in the population – The Paris Prospective Study I. Circulation. 1999;99:1978–1983.
