Guided by a patient's symptoms such as shortness of breath, chest pain or irregular heart rhythm, cardiologists have a variety of tools available to identify the cause of heart-related problems, including:

Stress testing
These testing procedures include an electrocardiogram (EKG), which monitors the electrical activity of the heart. During a stress test, specialists measure the changes in the heart during exercise.

Nuclear stress testing
When a more complete study of the patient's condition is necessary, patients may undergo advanced forms of stress testing. During this procedure a patient is injected with a precise amount of Cardiolite and the heart is scanned at rest and after strenuous exercise. The heart muscle absorbs the Cardiolite, which in turn creates an image on the scan. Blank spots in the image may reflect previous heart damage, points out Campbell. After exercise, additional spots on the scan indicate blockage of the vessel that supplies that area with blood.

Echocardiography
This diagnostic ultrasound test allows cardiologists to look at the heart without using x-rays or surgery. Echocardiography is used to track blood flow through the heart. Color-coded images produced by ultrasound provide extremely detailed information about the function and condition of the valves and walls of the heart, revealing possible abnormalities undetectable using other techniques.

Electrophysiology study
The electrophysiology study is a test that maps the electrical conduction system in the heart. It can help identify the cause of symptoms related to heart rhythm disturbance, assess abnormally slow or fast heart rates, or assess the effectiveness of medications that are taken to regulate a disturbance in the heart rhythm.

Cardiac catheterization
This procedure uses a special fluid, visible by x-ray, to locate blockages in the arteries that supply oxygen and nutrients to the heart muscle.

MRI imaging
Magnetic Resonance Imaging (MRI) technology provides high-quality, cross-sectional images of the heart and major blood vessels without x-rays or other radiation. During this procedure, the patient is exposed to short bursts of a powerful magnetic field that create shifts in the nuclei of the body's atoms. This creates a detectable radio signal that a computer converts into an image based on the strength of signals produced by different types of tissue.

PET scanning
Position emission tomography, also known as PET, is a diagnostic technique based on the detection of positrons (positively charged particles) that are emitted by substances injected into a patient's body. Pet scanning produces three-dimensional imagines that reflect the metabolic and chemical activity of the tissues being studied.

Holter monitoring
Patients wear this portable, 24-hour, electrocardiographic monitoring device which detects intermittent irregular heart beats or palpations.