Morteza Gharib and Abbas Nasiraei Moghaddam Show Function of Helical Band in Heart

Using an MRI technique, Morteza Gharib, Hans W. Liepmann Professor of Aeronautics and Professor of Bioengineering, and his colleague Abbas Nasiraei Moghaddam, a Caltech graduate and visitor in Bioengineering, were able to create some of the first dynamic images of normal heart muscle in action at the tissue level. They showed that a muscular band--which wraps around the inner chambers of the heart in a helix--is actually a sort of twisting highway along which each contraction of the heart travels. "We tagged and traced small tissue elements in the heart, and looked at them in space, so we could see how they moved when the heart contracts," Gharib explains. "In this way, we were able to see where the maximum physical contraction occurs in the heart and when--and to show that it follows this intriguing helical loop."