Scientists are pursuing clues that factors like infectious agents might also be culprits. Ultrasound pictures have shown that large plaques often exist in what angiogram X-rays portray as normal arteries. What causes the plaques to break is not known, but the inflammation is suspected to be a major factor. Like many cardiologists, Mr. Cheney would have been confused by the constant use of acronyms to describe the many heart studies that have established the safety and effectiveness of therapies and prevention procedures. The cardiology college lists more than such 160 acronyms.
Medicine progresses incrementally and in unexpected ways.
The condition can result from heart attacks and long-term starvation of heart muscle cells by constricted arteries that deprive the heart of a sufficient blood supply. Such research has focused largely on drugs. But in a surprising development, Dr. William T. Abraham, the head of cardiology at the University of Kentucky, reported a trial in which electrical therapy led to striking improvement among patients with severe heart failure characterized by certain abnormalities in their electrocardiograms. The therapy was delivered by a type of pacemaker made by Medtronic Inc. of Minneapolis. Two rigorous trials showed promise in the use of proteins known as growth factors to stimulate formation of new blood vessels, a form of angiogenesis, for people with blocked arteries in the heart or leg.