Additional methods of examination

Clinical blood analysis is without change.

Biochemical analysis in patients with stable angina may show elevated level of cholesterol, triglycerides, decreased high density lipoprotein cholesterol and increased low density lipoprotein cholesterol. Biochemical markers of myocardial damage in stable angina are in a normal range.

X-ray examination in stable angina does not provide specific information for diagnosis.

Resting ECG may show evidence of previous myocardial infarction, left ventricular hyperthrophy, bundle branch block, preexcitation, arrhythmias, or conduction defects, but is normal in most patients. Since 12-lead ECG is normal in 50 % of patients with chronic stable angina it cannot exclude 1HD. During chest pain the ECG becomes abnormal in half of the angina patients with a normal resting ECG. ST-segment and T-wave depression or inversion on the resting ECG and their pseudo normalization during pain are observed. Sinus tachycardia is common, bradyarrhythmia less go. These findings indicate that resting ECG should be performed during episode of chest pain.

Exercise ECG is more sensitive and specific than the resting ECG for detecting myocardial ischemia. Exercise tolerance test is usually performed using a standard treadmill or bicycle ergometer protocol to ensure a progressive and reproducible increase in work load while monitoring the patient's ECG, blood pressure and general condition. Planar and down sloping ST-segment depression of 1 mm or more is indicative of ischemia; up sloping ST-depression is less specific and often occurs in normal individuals. An exercise test should be carried out only after careful clinical evaluation of symptoms and a physical examination including resting ECG. Exercise ECG testing is not of diagnostic value in the presence of left bundle branch block, paced rhythm, and Wolff-Parkinson-White syndrome in which cases the ECG changes cannot be evaluated. Additionally, false positive results are more frequent in patients with abnormal resting ECG in the presence of left ventricular hypertrophy, electrolyte imbalance, intraventricular conduction abnormalities, and use of digitalis. Exercise ECG testing is also less sensitive and specific in women.

Resting two-dimensional and Doppler echocardiography is useful to detect or rule out the possibility of other disorders such as heart valve disease or hypertrophic cardiomyopathy as a cause of symptoms and to evaluate ventricular function. For diagnostic purposes, Echo-CG is useful in patients with clinically detected murmurs, history and ECG changes compatible with hypertrophic cardiomyopathy or previous myocardial infarction and symptoms or signs of heart failure. Tissue Doppler imaging allows regional quantification of myocardial motion and strain rate, imaging allows determination of regional deformation thus improve to detect ischemia earlier in the ischemic cascade.

Stress testing in combination with imaging are used in the diagnosis of stable angina. The most well-established stress imaging techniques are echocardiography and perfusion scintigraphy. Both may be used in combination with either exercise stress. Exercise stress echocardiography has been developed as an alternative to "classica" exercise testing with ECG and as an additional investigation to establish the presence or location and extent of myocardial ischaemia during stress. A resting echocardiogram is acquired before a symptom-limited exercise test is performed, most frequently using a bicycle ergometer, with further images acquired where possible during each stage of exercise and at peak exercise.

Exercise testing with myocardial perfusion scintigraphy is required. Thallium-201 and technetium-99m radiopharmaceuticals are the most commonly used tracers, employed with single-photon emission computed tomography in association with a symptom-limited exercise test on either a bicycle ergometer or a treadmill. With this technique myocardial hypoperfusion in patients with stable angina is characterized by reduced tracer uptake during stress in comparison with uptake at rest.

Pharmacological stress testing with imaging techniques. Pharmacological stress testing with either perfusion scintigraphy or echocardiography is indicated in patients who are unable to exercise adequately or may be used as an alternative to exercise stress. Two approaches may be used to achieve this: infusion of short-acting sympathomimetic drugs such as dobutamine in an incremental dose protocol which increases myocardial oxygen consumption and mimics the effect of physical exercise or infusion of coronary vasodilators (adenosine and dipyridamole).

Cardiac magnetic resonance stress testing in conjunction with a dobutamine infusion can be used to detect wall motion abnormalities induced by ischemia or perfusion abnormalities.