By Dr Ananya Mandal, MD
Angina is a symptom of an underlying heart disease and is manifested as chest pain that may or may not be brought about by physical exertion or by emotional stress.
Diagnosis of this condition and early management is vital in order to prevent the underlying disease process from progressing into a heart attack or stroke.
Angina is basically caused by narrowing of the coronary arteries that leads to lack of blood supply to the heart muscles leading to ischemic symptoms.
Diagnosis of angina includes asking questions about the patient’s history, physical examination, blood tests and so forth. 1-6
Patient’s medical history
History of similar condition, high blood pressure, high cholesterol, diabetes, smoking, alcohol intake, obesity etc. in the patient is important as these are important risk factors for angina.
Someone in the family may have heart disease or angina as these conditions may run in families.
A complete physical examination includes assessment of weight, waist size, height (to assess Body mass index – BMI with respect to weight) and features of high blood cholesterol like spots over the eye lids or a hardened feel of the arteries at the wrist etc.
Routine blood tests are prescribed to detect anemia (that may raise the risk of angina), cholesterol and glucose in blood as well as liver and kidney functions.
Urine examination is also advised to check on the kidneys. Liver and kidney function tests may guide medication to be used as some medications may not be used in patients with disorders of these organs.
Electrocardiogram (ECG or EKG)
This is a record of the rhythms and electrical activity of the heart. The test is a painless one where small electrodes or patches are stuck on various parts of the chest of the patient and the electrical activity of the heart is recorded onto a strip of paper.
Each heart beat has typical wave patterns and abnormalities of these waves (P, Q, R, S, T and U) may detect ischemia of the heart muscles in angina patients.
Echocardiography may be required to assess cardiac function, detect valve disease or cardiomyopathy as cause of angina.
Exercise tolerance test (ETT)
This is a similar test to ECG or EKG and is carried out while the patient is made to exercise under supervision. This may be with a treadmill or an exercise bike. This is also called a treadmill test.
This measures the amount of exercise that is required for the heart to develop symptoms of angina.
Myocardial perfusion scintigraphy (MPS)
This test is performed alternatively to ETT when ETT results are not diagnostic. This test involves injection of a small amount of radioactive substance into the patient’s blood.
This is then viewed using a gamma camera. This camera tracks the movement of the dye as it passes through the blood vessels of the heart and helps detects narrowing and obstructions.
It is performed when the patient is at rest and also when he or she is on the exercise bike or treadmill.
This is a more invasive test and may require a day of stay at the hospital. A thin flexible tube or catheter is threaded into a vein or artery at the groin (Femoral vein or artery) or at the arm (Brachial artery or vein). X rays are used to guide the catheter into the heart and coronary arteries.
A dye is injected into the catheter to highlight the coronary arteries. Repeated X rays and films show up the site of blockages.
Other tests for angina
Other tests include Stress echocardiography, Multi slice CT scan, first-pass contrast-enhanced magnetic resonance (MR) perfusion (MRI) and MR imaging for stress-induced wall motion abnormalities. These tests show the heart function as well as detect the area of calcified or hardened arteries that is leading to symptoms of angina.
For patients with unstable angina, treatment is a medical emergency. An immediate EKG or ECG is prescribed upon admission.
Blood tests like Troponin T levels and Creatinine K –MB levels are tested to look for damage to the heart muscles. A coronary angiography may also be performed to assess the size and site of blockage.
Ruling out other conditions
Angina symptoms may be confused with other conditions as well. These need to be ruled out for accurate diagnosis. These include:
- gastroesophageal reflux disorder
- heart attack or acute myocardial infarction
- acute pericarditis
- muscle pain or sprains or chest muscles or back muscles
- pleural pain
- pulmonary embolism
- aortic dissection
- acute cholecystitis etc.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)