April 17, 2006 (Monday)

Nonlinear Dynamics and Arrhythmias of the Heart

Stefan Luther
Laboratory of Atomic and Solid State Physics (LASSP)
Cornell University

Heart disease is one of the most prevalent diseases in the world and is the leading cause of death in industrialized countries. In the United States alone, heart rhythm disorders cause approximately 300,000 sudden deaths annually. Sudden cardiac death occurs unpredictably as a result of fast-developing electromechanical malfunctions of the heart. During normal functioning, the contraction of the heart is periodically triggered by planar electrical activation waves propagating across the heart followed by a refractory period. Numerical simulations suggest that during ventricular tachycardia (VT) the plane wave undergoes a transition to spiral waves (which are analogous to vortices in the Ginzburg-Landau model). Subsequently, spiral wave breakup results in a chaotic state corresponding to ventricular fibrillation (VF). Ventricular fibrillation essentially inhibits the contraction of the heart due to lack of spatial coherence. This becomes lethal to the organism if not stopped within a very short time. Some of the questions are: How are vortical structures created? How do they evolve and finally break up? Key to answering these questions is the development of a measurement system capable of imaging the spatio-temporal excitation patterns in cardiac tissues. Combining experimental data and complex nonlinear computer models of the heart, we are seeking strategies to understand and ultimately prevent sudden cardiac death. This understanding is key to the development of effective therapies, intelligent pacemakers and implantable micro defibrillators.
 

Time: 3:00 pm
Location: Lecture Room 5

The reception will be at 2:30 pm in room N201