Heart tests given by doctors help determine the cause of specific symptoms. Different tests provide different information. The most basic heart test can lead to more invasive diagnostic procedures. It is not uncommon for patients with symptoms of chest pain, swelling, fatigue, palpitations and shortness of breath to undergo a series of heart tests. The type of heart test ordered by the doctor depends on symptoms and medical history.
Electrocardiogram
An electrocardiogram, or EKG, is a test performed at the bedside or in the doctor's office to measure the electrical activity of the heart. It is painless and noninvasive. EKGs can potentially identify abnormal heart rhythm, electrical conduction abnormalities, past or current heart attack, heart enlargement and risk for heart attack in the near future.
Echocardiogram
An echocardiogram, or ultrasound of the heart, provides an image of the heart in motion. Another name is sonogram. This painless and noninvasive test involves placing a transducer over the chest that converts sound to images. An echocardiogram is ordered by a doctor to diagnose diseases of the heart valves, heart enlargement or cardiomyopathy, heart damage, infection, tumors and blood clots.
Nuclear Stress Test
A nuclear stress test is commonly used to diagnose coronary artery disease. Pictures of the heart are taken at rest and following exercise. A gamma-ray camera provides images of the heart with the help of a radioactive material that is injected during the test. A technician or nurse inserts an intravenous catheter to inject the material needed to image the heart. The patient lies on a table while the camera takes pictures of the heart at rest. The patient exercise on a treadmill, and then another injection is given and more images are taken. A physician might order a chemical nuclear stress test in place of exercise.
Exercise Stress Test
An exercise stress test involves exercise on a treadmill while the heart rate and rhythm is monitored with an EKG. The goal is to reach a target heart rate based on age or until fatigue, EKG changes or symptoms occur. Doctors look for specific changes in the electrocardiogram waves during exercise that could signal lack of blood flow to the heart from blocked arteries.
Cardiac Catheterization
A cardiac catheterization, or coronary angiogram, can diagnose blocked arteries. The test can also measure pressure within the heart and identify diseases of the heart valves. Under sedation, a thin tube is threaded through the artery in the leg or arm. A cardiology physician injects dye through the tube to see with an X-ray whether the arteries to the heart are patent--unobstructed--or blocked with plaque. Cardiac catheterization can be combined with stent placement and angioplasty to restore blood flow during the test.
Monitors
Heart monitors implanted under the skin and worn for 24 to 48 hours or placed on the chest and activated by the patient can diagnose heart rhythm disturbances that might not be detected by other testing. Monitors are useful when patients complain of palpitations or irregular heart beat during the night or intermittently. A heart monitor might also be ordered by a doctor to gauge the effectiveness of treatments and medications.
