Caltech scientists show function of helical ban...( PASADENA Calif.--Scientists from the...)

PASADENA, Calif.--Scientists from the California Institute of Technology (Caltech) have created images of the heart's muscular layer that show, for the first time, the connection between the configuration of those muscles and the way the human heart contracts.

More precisely, they showed that the 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.

Their findings were published in the December issue of the American Physiological Society journal, Heart and Circulatory Physiology.

Since the days of Leonardo da Vinci, observers of the human body have known that the heart's beat is not a simple in-and-out movement--that it has more than a little bit of a twist to it. "The heart twists to push blood out the same way you twist a wet towel to wring water out of it," explains Morteza Gharib, the principal investigator on the study, and the Hans W. Liepmann Professor of Aeronautics and professor of bioengineering in the Division of Engineering and Applied Science at Caltech.

Some 50 years ago, anatomist Francisco Torrent-Guasp was the first to show the helical configuration of the heart's myocardium--its muscular middle layer, the one that contracts with each heart beat.

But what he and subsequent generations of scientists were unable to do was to connect that myocardial band to the heart's function--to prove that the helical shape is important to the effective beating of the heart. Without that connection, physicians and scientists have tended to look at the heart as "just a piece of meat," says Gharib.

Until now, that is. Using a technique pioneered by Han Wen and his team at the National Institutes of Health, Gharib 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 myocardium in action at
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