Diagnosis & treatment

Tests used to assess your heart's health

Technical advances have resulted in dramatic improvements in your physician's ability to determine the condition of your heart more accurately than ever before.

Electrocardiogram (ECG or EKG)
The electrocardiogram is one of the most basic tests cardiologists use to gauge the health of your heart. This painless, noninvasive test analyzes your heart's electrical activity with the placement of electrode leads on your arms, legs and chest. The EKG yields a graphic record that looks like a series of waves representing each beat of your heart, which can help your physician detect whether you are having or have had a heart attack, whether there are disturbances in your heart's rhythm or a thickening of your heart wall.

24-hour EKG (Holter monitoring)
You go about your daily activities while connected via electrode leads to a small, portable recorder that continuously monitors your heart's activity. Holter monitoring is often accompanied by a written diary of your activities over a 24-hour period.

Exercise stress test
During a stress test, you exercise either on a treadmill or stationary bicycle while attached to the EKG machine via electrode leads. The test shows your physician how well your heart performs as more demands are made on it. Preparation

Pharmacologic stress test
For people who are unable to exercise, medications can be injected while the heart is being monitored by the EKG. These medications produce similar cardiovascular response as during exercise. Preparation

Chest X-ray
A chest X-ray may be taken to determine the size, contour and position of the heart. An X-ray can be useful in understanding some structural abnormalities or the presence of complications such as congestive heart failure. An X-ray can also guide placement of cardiac catheters, such as pacemakers and pulmonary artery catheters.

Blood tests
You may be given blood tests that measure the presence of enzymes stored in the cells of your heart. When you experience a heart attack, damaged cells within your heart release enzymes into the blood stream.

Nuclear scans
Small amounts of radioactive substances are injected into your body passing through the bloodstream and into the heart. A scanner indicates which areas of the heart are not getting sufficient oxygen. Nuclear scans are often used during an exercise stress test. This allows for comparison of resting and exercise images. Preparation

Echocardiogram (echo)
During an echo, the size of your heart and its chambers are measured using sound waves. Echos show your doctor whether your heart is pumping normally and whether your heart's valves are performing as they should. An echo may be used during exercise stress testing. Preparation

Transesophageal echocardiogram (TEE)
A variation on the echocardiogram involves the threading of a small transducer through the mouth and into the esophagus. This technique provides clearer ultrasound images because the sound waves pass through less tissue. Complications arising from sedation or the use of topical anesthesia are uncommon but can be serious. A history of dysphagia or radiation therapy to the chest increases the risk for complications. Preparation

Cardiac catheterization (cardiac cath)
A cardiac cath or angiogram is a procedure that identifies possible problems with your heart or its arteries. During a cath, which takes between one and two hours, a thin plastic tube, called a catheter, is inserted into a blood vessel in your groin or arm. The catheter is guided up toward your heart. A special dye is injected into the catheter so that X-rays can show if you have any artery blockage or other heart problems. Preparation

Positron emission tomography (PET)
This noninvasive scan, used initially to study neurologic dysfunction, is now being used to diagnose cardiac problems. In many cases it can provide more specific information than is available from other tests and can be useful in planning a course of treatment (for example, would bypass surgery or angioplasty be beneficial). Radioisotopes are injected to measure blood flow and metabolic function. A detailed three-dimensional image is produced. Preparation

Your cardiologist can advise you which, if any, of these tests may be useful in answering questions you may have about the health of your heart. If you need a cardiologist, try Physician Referral Online to find a specialist affiliated with Yale-New Haven.

Preparing for cardiac diagnostic tests

Preparing for an exercise stress test
You will be asked to fast for four hours before the test and avoid stimulants such as tobacco and caffeine. Medications may be taken with sips of water. Your physician may ask you to not take certain cardiac medications before the test, such as beta blockers. Clothes and sneakers or rubber-soled shoes for exercising should be worn. Women should wear a supportive bra. You will be monitored during the test and for 10-15 minutes after the test.

Preparing for a pharmacologic stress test
You will be asked to not eat or drink for four hours before the test, particularly chocolate, caffeine or caffeine-free coffee, tea, carbonated beverages or medications containing caffeine such as Anacin or Darvon. If caffeine is not avoided, the test may have to be rescheduled. Patients on certain medications may be asked to stop taking the medication for 24-48 hours before the test. You may experience a temporary flushed sensation or nausea as the drug to be used is administered. This sensation should pass quickly. Any other symptoms you experience during the course of the test should be reported to the cardiologist or nurse. The stress test may take about an hour, or as many as three hours if imaging is performed at the same time.

Preparing for an echocardiogram
The test is painless. Gel will be applied to your chest to help transmit sound waves. The test takes 30-45 minutes, during which time you might have to turn onto your left side or hold your breath. The monitoring is performed as a small transducer that emits sound waves is moved about the chest.

Preparing for a transesophageal echocardiogram
You will be asked to not eat or drink for six hours before the test. An IV will be started to administer dobutamine and sedation. Your throat will be anesthesized before the probe is inserted. Blood pressure and EKG are monitored throughout the procedure. You will be sedated but will be aware and able to follow commands and answer questions. After the study, you will be monitored for 30 minutes to an hour. You will not be able to eat or drink for four hours and you may have a sore throat for 24 hours.

Preparing for nuclear scans
Talk with your physician about what type of nuclear scan you will be receiving. In the case of one type of nuclear scan, you may have to keep your arms over your head for 20-30 minutes. If you are unable to do this, another type of nuclear scan may have to be performed. Your physician should discuss with you what type of stressor will be used--exercise or medications--and the type of imaging technique to be employed. Please be assured the tracers used in these procedures are safe, involving radiation exposure similar to other diagnostic X-rays. You will not have to take any special radiation precautions after the procedure.

Preparing for cardiac catheterization
Staff will ask you before the procedure if you've had previous reactions to contrast medium (used to see the coronary arteries), or if you have allergies to shellfish. Blood tests will be done to screen for problems which might complicate your recovery. You will be asked to fast for 8-12 hours before the procedure. Many people receive this type of test as an outpatient. If so, you will be asked to bring someone to drive you home. The procedure itself will require you to lie on a table for no more than two hours. A mild sedative will be used which will make you feel sleepy, but you will awaken easily. Staff will discuss with you the sensations you may feel during the procedure. Prior to the procedure, you will have an IV placed. The sedation you receive will help reduce anxiety. During the procedure, your blood pressure and EKG will be monitored constantly. Your doctor may also want to have an angioplasty performed immediately following the cardiac catheterization. During recovery, you will need to rest in a bed for up to eight hours. If you leave the hospital the same day, you may be asked to do the following:

• Do not bend, strain, lift heavy objects or take a tub bath for the next 24 hours. A shower is OK.
• Talk with your doctor about when you can return to work, drive or resume strenuous activities.
• Call your doctor if you have bleeding, swelling, new bruising or pain from the puncture site, or a temperature of 101.5 F or more.
• If your test shows you have coronary artery disease, talke with your doctor about treatment options, including cardiac rehabilitation.
• Talk with your doctor about lifestyle changes that could help reduce your risk for future heart problems.

Preparing for PET scan
In some cases, you may be asked not to eat prior to the test. Since PET evaluates glucose metabolism, your blood sugar should be in the normal range during the test. You should refrain from tobacco and caffeine for four hours before the procedure. Your exposure to radiation will be minimal and at a safe and acceptable level.

• YNHH Health Library: Cardiac diagnostic tests

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Last revised: May 23, 2007 (dh)

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