Heart disease may cause many of the recognizable symptoms mentioned above like shortness of breath and chest pain, or it may cause no symptoms at all until it is too late. Seeing your doctor for regular physical examinations may allow your doctor to notice signs of heart disease before you ever experience symptoms. Your doctor can assess your risk factors for developing heart disease, which include: advancing age, family history of heart disease, high blood pressure, high cholesterol and triglycerides, obesity, diabetes mellitus, sedentary lifestyle, and exposure to tobacco smoke.

If your doctor determines that you are at elevated risk for developing heart disease, he or she may order further tests to assess heart function. The main tests that can diagnose heart disease and heart attacks are below.

Non-invasive tests

Electrocardiogram (EKG or ECG)

The ECG records the electrical activity of the heart using electrodes that are positioned on the chest. The ECG detects abnormalities in heart rhythm (arrhythmias) and can determine if you recently suffered a heart attack and predict if a heart attack is developing.

Chest X-ray

An X-ray of the chest can show if there is fluid accumulating in the lungs as commonly happens in heart failure and can also show if the heart is enlarged, which can occur when the heart is working too hard to pump blood through arteries narrowed by atherosclerosis.

Echocardiogram

An echocardiogram uses ultrasonic waves to produce an image of the heart in action similar to an ultrasound image of an unborn fetus. The echocardiogram shows structural problems with the heart, such as cardiomyopathy, and can also diagnose arrhythmias.

Exercise stress test

A stress test involves donning a lot of recording equipment and jogging on a treadmill to measure how your heart reacts to the stress of exercise. Heart rate, breathing rate, blood pressure, and ECG can be monitored simultaneously. Abnormal findings on the stress test can diagnose coronary artery disease or diagnose the cause of angina. It can also help determine what level of exercise is safe for you and also predict impending heart attacks.

Invasive tests

Blood tests

Blood samples can be assessed for levels of proteins and enzymes related to heart disease. Important measures include cardiac enzymes (including troponin and creatine kinase), C-reactive protein (CRP), fibrinogen, homocysteine, lipoproteins, triglycerides, and brain natriuretic peptide (BNP).

Coronary angiogram

An angiogram involves threading a flexible catheter through an artery in the leg up into the heart, then injecting a dye into the coronary blood vessels. An X-ray machine then allows visualization of the blood flow through the coronary arteries. Angiography is one of the most useful and accurate tools in diagnosing where and to what degree the coronary arteries are narrowed by atherosclerosis. It also measures blood pressure within the heart, blood oxygenation levels, and can help evaluate heart muscle function.

Thallium stress test

Just like the noninvasive exercise stress test mentioned above but with the addition of an injection of radioactive thallium before the test. This allows pictures of the heart in action to be taken with a special gamma camera. In addition to the findings of a noninvasive stress test, the thallium test measures blood flow of your heart muscle at rest and during stress and helps determine the extent of coronary artery blockage.