What is a stress test?

A stress test, also called a cardiac stress test, shows how exercise affects your heart. A stress test determines how much exercise your heart can tolerate before having a problem. Doctors use stress tests to diagnose and monitor coronary artery disease, cardiac ischemia (not enough blood flow to the heart muscle), cardiac arrhythmias (abnormal heartbeats), and other types of heart disease.

A stress test is only one method to monitor and diagnose heart conditions. Discuss all of your testing options with your doctor to understand which options are right for you.  

Types of stress tests

The types of stress tests include:

  • Standard or regular stress test (exercise stress test or treadmill test) involves walking on a treadmill or pedaling a stationary bicycle. If you cannot exercise due to a medical condition, your doctor may give you a medication called dobutamine to make you heart work as hard as it would during exercise. This is called a pharmacological or dobutamine stress test.
  • Nuclear stress test involves using an IV radioactive dye and taking pictures of your heart during a stress test. Nuclear stress tests include a thallium stress test, sestamibi (Cardiolite) stress test, and PET (positron emission tomography) stress test.
  • Stress echocardiogram uses sound waves to take moving pictures of your heart during a stress test.  

Why is a stress test performed? 

Your doctor may recommend a stress test to determine how well your heart handles work. A stress test is not a routine screening test, and a stress test by itself cannot diagnose all types of heart conditions or predict future heart problems. It provides important information about your heart health in relation to your age, physical exam, medical history, and other tests. 

Doctors use stress tests to help diagnose or monitor the following conditions:

  • Cardiac arrhythmias including heartbeats that are too fast, too slow, or irregular, especially arrhythmias that occur during exercise 
  • Cardiomyopathy, thickened or enlarged heart muscle 
  • Congenital heart defects, birth defects of the heart 
  • Coronary artery disease (CAD), a buildup of plaque on the walls of the coronary arteries that supply blood to the heart
  • Heart attack, death of a portion of the heart muscle usually due to coronary artery disease and a blood clot that blocks blood flow to the heart
  • Heart failure, an inability of a weakened heart to pump enough blood to the body
  • Heart valve disease including narrowed valves and leaky valves
  • Pericarditis, inflammation of the sac that surrounds the heart 

Your doctor may also perform a stress test to:

  • Determine if certain symptoms are related to coronary artery disease (narrowing of the coronary arteries). Symptoms can include chest pain, dizziness, shortness of breath, fatigue, weakness, palpitations, passing out, or feeling a pounding, racing or irregular heartbeat.
  • Determine the kind of exercise and how much exercise is healthy and safe for you if you have heart disease or a high risk of heart disease due to diabetes, family history, obesity, and other conditions
  • Further evaluate abnormal heart test results such as changes on a standard, resting EKG (electrocardiogram)
  • Monitor your heart condition after a heart attack, angioplasty, heart transplant, or heart bypass surgery

Who performs a stress test?

The following specialists perform a stress test:

  • Cardiologists and pediatric cardiologists specialize in conditions and diseases of the heart and blood vessels. Pediatric cardiologists further specialize in treating infants, children and adolescents.
  • Clinical cardiac electrophysiologists specialize in diagnosing and treating abnormal heart rhythms (arrhythmias) using heart and blood vessel imaging and technical procedures.
  • Interventional cardiologists specialize in diagnosing and treating conditions and diseases of the heart and blood vessels using nonsurgical, catheter-based procedures and specialized imaging techniques.
  • Cardiac surgeons specialize in the surgical treatment of conditions of the heart and its blood vessels. Cardiac surgeons may also be known as cardiothoracic surgeons.
  • Advanced heart failure and transplant cardiologists care for people whose heart failure no longer responds to conventional therapies and symptom management.