Scientists show function of helical band in heart

With each beat of the heart, a wave of contraction starts at the heart's apex--which, despite its name, is actually at the very bottom of the heart--and then travels up through the myocardium. "The only time the whole helix shows up in the images is at the end of systole, which is when the heart is contracting," says Gharib. "This simple band structure is akin to an engine behind the heart pumping action."