Diagnostic Testing

Emerson Cardiovascular Associates provides comprehensive care, including most of the tests that our patients require. Other than nuclear stress tests and cardiac catheterization, we provide the following diagnostic tests right in our Concord office.

A staff member assisting a patient.

Electrocardiogram (EKG)

This test detects and records the heart’s electrical activity, including how fast the heart is beating and its rhythm. This information can reveal several different heart problems, such as a heart attack, lack of blood flow to the heart or an arrhythmia (abnormal heart rhythm).

What you experience: An EKG is painless and takes about ten minutes to perform. After undressing from the waist up, you will lie down and have soft EKG leads attached to your chest. The machine then records the electrical signals on graph paper.


This test uses ultrasound waves in order to show the heart’s structure and movement, including how well it is pumping. An “echo” also reveals if the heart is enlarged and if the valves are functioning normally.

What you experience: An “echo” is painless and takes about an hour to perform. After undressing from the waist up, you will have gel applied to your chest so that the transducer—a microphone-like device—can be easily moved around. The sound waves that the transducer transmits are converted into images of your heart that can be evaluated by your doctor. For patients who require more advanced testing, a transesophageal echocardiogram may be ordered. It is used to assess the overall function of your heart’s chambers and valves.

Stress tests

These tests provide us with information on how your heart works when it is under physical stress. Stress testing is often used to diagnose coronary artery disease or to determine if your medication is effective at increasing blood flow, as well as to diagnose an arrhythmia.

What you experience: After electrodes are attached to your chest, you will exercise on a treadmill wearing a blood pressure cuff. Our technologist will remain with you throughout the test in order to monitor your condition.

Ambulatory monitoring

These monitors are worn over time, usually a 24-hour period, in order to detect heart rhythm problems, to determine if treatment is working or to detect silent myocardial ischemia—a condition where insufficient blood is reaching the heart muscle.

What you experience: All ambulatory monitors use sensors that are attached to the chest. The monitor itself can usually be clipped to a belt or carried in a pocket. A Holter monitor—one of the most commonly used—is about the size of a deck of cards. A ZIO patch is a device—about the size of a small pillbox—that attaches to the chest via an adhesive. Emerson Cardiovascular Associates also performs event monitoring for up to 30 days to evaluate intermittent cardiac issues.

Nuclear stress tests

This test measures blood flow to the heart—both when you are at rest and when you are exercising. If an exercise test did not determine the cause of symptoms, such as chest pain, a nuclear stress test is often the next step. The images from a nuclear stress test also can reveal whether or not the heart is enlarged and can help determine if treatment is working. These tests are performed at Emerson Hospital.

What you may experience: You may be asked to refrain from eating, drinking or smoking prior to a nuclear stress test. After electrodes are placed on your chest, legs and arms, an EKG is performed, and a blood pressure cuff is placed on your arm. Once you begin exercising and reach the target heart rate, a radioactive agent is injected through an intravenous line in your hand or arm. It travels to the heart and produces images that we will study and use for diagnosis.

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