A number of alternative stress tests are available for patients unsuitable for exercise stress testing
Myocardial Perfusion Scan
A myocardial perfusion scan (MPS) uses a small amount of a radioactive chemical assess blood flow to the heart muscle. This scan is performed after gentle exercise and/or with a drug to increase cardiac blood flow to see how the heart muscle responds under stress.
Myocardial perfusion scans are used to try to identify whether chest pain is of cardiac origin and whether or not any coronary arteries are blocked and by how much. It can also be used to determine the extent of injury to the heart following a heart attack.
NICE-released guidance in 2003 recommended MPS imaging;
As a first-line diagnostic tool for the exclusion of coronary artery disease in patients for whom exercise stress testing poses problems in interpreting or where sensitivity is poor. This may include women, patients with cardiac conduction defects (eg left bundle branch block) and for people who have difficulty using a treadmill for whatever reason.
As part of an investigation strategy in patients with a lower risk of coronary artery disease as a less invasive alternative to coronary angiography.
In patients with established coronary artery disease with persistent symptoms after a myocardial infarction or after treatment with coronary stenting or bypass surgery to determine the cause and extent of any remaining abnormality.
Dobutamine Stress Echocardiography (DSE) is a test employed to assess the function of your heart and whether it receives an adequate blood supply under stress similar to a MPS. It can be used to diagnose or assess coronary artery disease. It is particularly useful in assessing whether certain parts of the heart are permanently damaged after a heart attack or whether some recovery is possible.
The test involves performing an echocardiogram and either undertaking exercise on a bicycle ergometer or giving a drug into a vein (dobutamine) that mimics the effects of exercise on the heart. It is often used on patients who cannot perform a treadmill test due to arthritis or other physical limitations. It is also useful when the results of the treadmill test are suboptimal.