Sudden cardiac death still a mystery.

• Position: Heart Disease

Sudden cardiac death (SCD) is a catastrophic disruption of the heart rhythm that can cause a seemingly healthy human to drop dead without warning. More people die from SCD each year than from AIDS, breast cancer, and lung cancer combined. The condition accounts for nearly 60% of all cardiovascular-related deaths, claiming the lives of approximately 300,000 people per year in the U.S.

Yet, because there are few warning signs or symptoms to identify people at risk, and since SCD is, by definition, fatal, leaving no survivors to study, scientists know little about the underlying mechanisms that cause the condition. The Center for Research in Cardiovascular Medicine at the University at Buffalo (N.Y.) is poised to change that scenario. The university has assembled a cadre of specialists in several fields who are investigating SCD from the single-cell level up, with the goal of developing strategies for treatment and prevention.

"Great strides have been made in treating ischemic heart disease, heart attack, and heart failure," points out John M. Canty, Jr., director of the center. "However, the impact of these developments on sudden cardiac death is disappointing. The percentage of sudden deaths is increasing, while mortality from other cardiovascular causes continues to decline. As a result, sudden death has become one of the nation's major public health problems."

A multidisciplinary team encompassing specialists in cardiology, physiology, biophysics, biochemistry, genetics, pharmacology and toxicology, positron emission tomography (PET) scanning, and electrophysiology is interested particularly in studying a phenomenon called "hibernating myocardium," in which hear cells receiving a depleted blood supply due to arterial narrowing adapt to the life-threatening situation by reducing their function and oxygen needs. The cells remain viable and are able to result normal activity if and when surgery restores full blood flow.

Nevertheless, since areas of hibernating myocardium exist side-by-side...