Circadian Rhythms and the Heart

Researchers at Case Western Reserve University School of Medicine have uncovered the first molecular evidence linking the body's natural circadian rhythms to sudden cardiac death.

heart rhythm

Mukesh K. Jain, MD, Darwin Jeyaraj, MD, and colleagues discovered a genetic factor called Kruppel-like Factor 15—or KLF15—that links the body's natural clock to the heart's electrical activity system. Too much or too little KLF15 causes a disruption in the heart's electrical activity, greatly increasing susceptibility to arrhythmias.

These abnormal heart rhythms, which are the most common cause of sudden cardiac death, occur most frequently in the morning and evening. While scientists have been aware of these patterns in the heart's electrical stability for years, this discovery provides insight into the biological mechanism behind the variations and suggests therapies that modulate the biological clock could be beneficial in preventing sudden cardiac death.