Diagnosis
Doctors diagnose angina with the help of several tools. The main challenge here is to differentiate between the several causes of chest pain and differentiate between stable and unstable angina. These tools include:
Medical history: The basis of medicine is medical history. Your doctor will ask you several questions that will help him understand the cause of your discomfort or complaint. Regarding angina, the main questions involve the pattern, site, duration, severity, time of pain, and what alleviates or aggravates it.
Physical examination: A general physical examination is routine, although it doesn’t always show abnormalities. It involves measuring blood pressure and auscultating heart sounds, indicating cardiac abnormalities that either caused or aggravated the condition. Also, signs of heart failure indicate a severe condition that needs more invasive treatment and diagnostic considerations. The doctor may also check your leg edema and auscultate the chest for volume overload evidence, which indicates late-stage heart failure. A physical examination can also be useful in excluding other chest pain causes as muscle pain or problems in the lungs or airways. A reproducible pain usually excludes angina. A general look at the whole body’s blood vessels is also a part of the routine physical examination of patients with cardiac conditions. It includes checking peripheral pulses and carotid auscultation and palpation for signs of occlusion.
Lab investigations: Lab investigations offer an excellent “exclusion tool” for unstable angina. The most important of which is cardiac markers. When heart cells die, the various enzymes involved in the mechanism of their contraction “leak” into the bloodstream. Since there is no death or “necrosis” of heart cells in unstable angina, the presence of high levels of such enzymes is strongly suggestive of a heart attack. Other routines -but not insignificant- investigations include:
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- Blood sugar and hemoglobin A1C levels for diabetic patients.
- Lipid profile
- Electrolyte levels, especially potassium and magnesium. A drop in the level of such electrolytes can prove fatal in unstable angina patients, as it can cause arrhythmia.
Electrocardiography: Electrocardiography is the most commonly done investigation for chest complaints, and rightly so. It is easy to do and can exclude many diagnoses, a good portion of which is fatal. In the case of unstable angina, there is no classical finding. However, the ST segment changes -which is when the ventricles restore their electrical polarity and relax- is highly suggestive of a severe episode that needs immediate intervention.
Echocardiography: Both transesophageal and transthoracic echocardiography may be used -although the former is recommended-. Echocardiography can detect abnormalities of the heart’s contraction and sequelae of heart attacks or the presence and assessment of heart failure. It can also exclude other causes of chest pain related to the heart as valvular disorders.
Magnetic resonance imaging: The main advantage of MRI is its high resolution. What can’t be seen by echocardiography can easily be picked by an MRI. It can detect microinfarcts and visualize coronary arteries with great accuracy.
