New Drug Prevents Deadly Cardiac Arrhythmias, Using Fmri To Examine Sleep Deprivation's Impact On The Brain

Heart researchers at Columbia University Medical Center have developed and tested a unique heart arrhythmia drug that could prevent the sudden death of millions of people with heart failure, as well as people with an  inherited heart disorder exacerbated by exercise. The drug represents one of the first molecular-based therapies for cardiac arrhythmias and heart failure and avoids the toxicity of current treatments. Results of the initial animal test are published in the April 9 issue of Science.

In the new study, investigators tested the experimental drug in mice that had the same molecular defect as people with heart failure and some otherwise healthy people who develop fatal arrhythmias during exercise.

The defect causes a tiny channel in the heart muscle to leak calcium ions into heart cells, triggering arrhythmias in both types of patients). The researchers found that the drug completely prevented sudden death from arrhythmia. All 10 mice that received the drug thrived and never developed the problem, while 8 out of 9 untreated mice became arrhythmic and died.

“The drug will be an incredible advance if it works in patients,” says Andrew Marks, M.D., chairman of physiology and cellular biophysics at Columbia University College of Physicians & Surgeons, director of Columbia's Center for Molecular Cardiology, and leader of the new study. “It represents the beginning of an era when drugs will directly fix the molecular defects in heart failure. While our drug is one of the first molecular-based therapies for heart failure and arrhythmias, it won't be the last.”

For more information, to receive a copy of the full press release, or to arrange an interview with Dr. Marks, contact Annie Bayne at 212-305-3900 or as862@columbia.edu.

RESEARCH: Defining brain network affected by lack of sleep Researchers know that sleep deprivation acts as a brake on the brain, slowing alertness, reaction time, and memory. But until recently, scientists have been looking at the brain section by section to see which areas are affected by lack of sleep.

Now, Columbia University Medical Center researchers, taking a more holistic approach, have used functional magnetic resonance imaging (fMRI) in two recent studies to determine which brain areas change their activity levels together to form a network associated with sleep deprivation. In the latest study, Dr. Yaakov Stern,professor of clinical neuropsychology, Dr. Christian Habeck, postdoctoral research scientist in Columbia's Taub Institute, and colleagues examined the effects of sleep deprivation on the short-term memory of 19 young adults who went two days without sleep. The researchers identified a network of brain areas whose activity levels dropped after sleep deprivation and correlated with diminished memory performance.

“Although further research is needed, our findings suggest which brain regions need to be stimulated during sleep deprivation to overcome the cognitive effects of sleep loss,” Dr. Habeck says. The research was published March 28 online in the journal Cerebral Cortex.

For more information, contact Annie Bayne at 212-305-3900 or as862@columbia.edu.