T-wave alternans is a test that looks at microvolt changes in the T-wave on a beat to beat
basis. The presence or absence of such changes has been shown to predict or exclude future
arrhythmic events. The mechanism of T-wave alternans is unclear, but may relate to calcium
metabolism in the heart, and may be affected by conditions such as ischemia or heart
The purpose of this study is to determine whether T-wave alternans, as measured through the
lead of an implantable defibrillator, is produced by acute ischemia induced by occlusion
during percutaneous coronary interventions.
- patient with CAD undergoing PCI with appropriate Medtronic implantable defibrillator.
- non-elective procedure
- non-qualifying defibrillator type.