Heart capillaries may build natural bypasses for blood flow after heart attacks

The heart powers a busy highway of arteries and vessels, providing a constant to-and-fro passage for blood. During a heart attack, this passage becomes blocked, usually when a blood clot forms on plaque in a coronary artery and cuts off blood flow to the heart muscle. A study published in Science found that the heart tries to save itself by growing new natural bypass channels to bring blood and oxygen back to damaged tissue.