Jan. 5, 2007 — A report in the January issue of the Journal of the American College of Cardiology finds that as many as a third of Americans who get implantable defibrillators might not need them. The University of Michigan Medical Center study says that as much as $690 million could be saved in Medicare spending for the devices.
The study found that a test known as MTWA — which costs about $400 — may provide better answers about how well the heart pumps blood, but more research must be conducted before it is widely accepted as a screening tool, said Dr. Paul Chan, senior author of the study.
Microvolt T-wave alternans measures changes in calcium levels in the heart, Chan said. The test is conducted similarly to a treadmill stress test, only less vigorously.
February 12, 2024 
