“Understanding and preventing sudden cardiac death”

Sudden cardiac death kills hundreds of thousands of North Americans each year. This number could be reduced significantly if a medical device - the implantable cardiac defibrillator - had been implanted prior to the sudden death. However, since we do not have good ways of predicting who will suffer sudden cardiac death or when, physicians face a major problem in deciding in whom to implant a cardiac defibrillator. This problem is made more severe since implantable cardiac defibrillators are expensive, and complications, though rare, do add to the risk of using the devices in those who would not benefit. In this talk I will describe attempts to understand cardiac arrhythmias - especially those responsible for sudden cardiac death. A goal is to understand the mechanisms of arrhythmias sufficiently well in an individual patient, that it is possible to better assess the risk of sudden death in that patient. To help understand arrhythmias, I use methods that include analysis of electrocardiographic records of patients who experienced sudden cardiac death, recording activity in tissue culture models of cardiac arrhythmias, and the formulation of mathematical models of cardiac arrhythmia employing a range of techniques from number theory to nonlinear dynamics.