Noninvasive investigations

Non-invasive investigations include resting ECG, exercise tolerance testing, thallium perfusion scanning (exercise or pharmacological stress), stress echocardiogram, and isotope ventriculography. The investigation of angina can confirm the diagnosis and may also give some indication of disease severity and prognosis.


The resting ECG may be normal or show evidence of previous myocardial infarction in one or more territories. There may be evidence of hypertension, such as left ventricular hypertrophy. ECG changes may be subtle and non-specific, such as ST segment flattening in the lateral leads or T-wave inversion inferiorly.

Stress testing

In the presence of significant coronary stenosis, exercise or other chronotropic and inotropic stimuli (e.g. infusion of adrenergic agonists such as dobutamine) will result in localized ischemia. This manifests itself as typical pain and also results in changes in the contractility of the ischemic myocardium, which can be detected by echocardiography (stress echo) or isotope ventriculography (multiple-gated acquisition (MUGA) scanning). ECG changes are repolarization abnormalities with ST segment depression. Thallium-201 is distributed in the myocardium in proportion to blood flow. Areas of infarction and scar tissue do not take up the isotope, and ischemic areas take up less than normal. The isotope is detected by a gamma camera.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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