How to Diagnose Angina Pectoris?

The most important element in the diagnosis of Angina Pectoris is the clinical history and the characteristics of chest pain. The clinical context is also important since coronary heart disease, and hence Angina Pectoris, is more common with increasing age, in men and in patients with associated risk factors.

Physical Examination and Resting ECG

Physical examination and resting ECG are standard, but are usually normal. An abnormal resting ECG is associated with a worse prognosis and left ventricular dysfunction. Echocardiography may confirm left ventricular impairment or previous infarction, but need not be performed routinely in every case where the ECG is normal and there is no evidence of valve disease on examination.

Exercise ECG to Diagnose Angina Pectoris

A negative maximal treadmill exercise ECG test is associated with a good prognosis but does not exclude a diagnosis of angina pectoris except in patients in whom the pre-test probability is low. Its overall diagnostic sensitivity is 60 per cent, and the specificity is only slightly higher. In patients in whom the diagnosis of angina is certain, based on typical symptoms and a high pre-test probability of disease, the only reason for performing an exercise ECG is to establish the prognosis since a negative test will not refute the diagnosis.

Stress echocardiography and single photon nuclear perfusion imaging have higher diagnostic accuracies, but require greater expertise and should only be used where there is rigorous in-house quality control.

Positron Emission Tomography

The most reliable non-invasive test is Positron Emission Tomography (PET) which has a 95 per cent sensitivity and specificity. It is expensive and is not yet widely used.

Coronary Angiography

Coronary angiography is often reserved only for cases where intervention is contemplated. This is to ignore its valuable diagnostic role in cases of clinical uncertainty or where strong reassurance is needed. Unlike the non-invasive tests, it is associated with a definite mortality, although in experienced centers this is low and less than 1 in 1000.