Q. Describe False Negaive Tests?

When patients are found to have significant coronary narrowing and fail to have exercise induced ST depression, they have been labeled false negative. This can be understood when the obstructed artery subtends an area of scar, suggesting that there is no ischaemic muscle to produce the characteristic ECG changes. Indeed, the prevalence of an ischaemic ST response is reduced in subjects with a previous infarction, especially if it is a large anterior wall scar.