Resident Physician

Internal Medicine

University of California, San Francisco (San Francisco, CA)

Using a combination of experimental studies and computational/mathematical modeling, I studied the mechanism of so-called "subcellular alternans" in cardiac myocytes, in which a well known dynamical mechanism of pattern formation causes a spontaneous desynchronization of subcellular calcium transients within individual cells.

Using both a theoretical and experimental biophysical approach, I studied the basic mechanisms of cardiac repolarization alternans, a common cardiac rhythm which is a precursor to ventricular tachycardia, ventricular fibrillation, and sudden cardiac death. Alternans, seen clinically as beat-to-beat alternations in T-wave amplitude on the electrocardiogram, is a manifestation of cardiac myocyte dynamics at the subcellular, cellular, and tissue level. My work employed a combination of mathematical physics, computational modeling, and experimental electrophysiology to study the mechanisms of this phenomenon, and proved that a common mechanism of physical pattern formation (a ``Turing instability'') may underlie the formation of alternans at multiple spatial scales. In addition to providing novel insights into the basic mechanisms of a clinically important rhythm disturbance, this may also represent the first explicit biological example of a Turing instability since it was first proposed in 1952.