Heart Disease Diagnosis
The following are some of the tests performed to help diagnose cardiovascular disease:
Treadmill Stress Test
This test measures the general strength of your heart and its capacity to "keep up" with your level of activity. The most common indication for a treadmill stress test is to evaluate chest pain which may or may not be heart related (angina). Stress tests may also be used as part of a physical examination for healthy, middle-aged individuals to establish cardiac fitness for certain occupations, or when such individuals have been sedentary and want to start a program of vigorous exercise such as jogging.
As its name implies, a treadmill stress test creates an increased level of work, or stress, for the heart. This is done to reproduce symptoms -- such as chest pain -- that you may encounter during physical exertion in the course of everyday activities. Stress tests are performed by trained technicians in the hospital or doctor's office. The test has a very high safety rate and reliable results, and is less expensive than some other diagnostic procedures. If your stress test is positive, you will receive a cardiologist evaluation within 48 hours.
Preparing For Your Test
When your test is scheduled, let your doctor know what medicines you take, and inquire whether you should take your medications before the test. Don't eat, drink (only sips of water) or smoke for three hours before your test. If you are diabetic, ask what you may eat before the test.
Wear walking shoes and a two-piece outfit. You may need to undress from the waist up and put on a short hospital gown. A technician or nurse will clean several areas on your chest and shoulders to prepare the skin for a series of electrodes. (Men may need to have these areas shaved to ensure that the electrodes adhere properly.) The electrodes are small, self-adhesive patches connected by wires to an ECG machine that monitors your heart rate. You will also wear a blood pressure cuff during the procedure to monitor your pressure.
You will be shown how to step onto the treadmill and use the support railings to maintain balance. The technician will start the treadmill slowly, then increase the speed and incline gradually throughout the test. The goal is to reproduce symptoms within the first 6 to 15 minutes of physical exertion.
Your stress test ends when you become too tired or begin to feel pain, when significant changes in the ECG occur, or when you achieve your target heart rate. The ECG can detect and measure a cardiac abnormality even when it does not cause pain. You should tell the technician if you feel discomfort in your chest, arm, or jaw, or if you experience shortness of breath, fatigue, dizziness, or leg cramps
Once you're off the treadmill, you'll sit down and the technician will monitor your blood pressure and ECG for another five to 10 minutes. Your electrodes will be removed, and the electrode sites will be cleaned.
Typically, a treadmill stress test takes about 45 minutes, which includes preparation, exercise and a cool-down period. You may be able to receive preliminary results before you leave. A complete interpretation may take several days.
More than one million stress tests are performed each year with a very low risk of complications. The risks are presumably higher in patients with severe heart disease. Still, no procedure is 100-percent risk-free. Your technician will ask you to sign a consent form before your test. Feel free to ask any questions about the procedure at this time.
An echocardiogram (echo) is a test that uses ultrasound waves to produce an image of your beating heart. It is a safe, painless procedure performed in a hospital, test center, or doctor's office.
An "echo" reveals the size of your heart, its pumping strength, valve function and other important information. It is one of the most common non-invasive techniques used in the diagnosis of heart disease today. Sometimes, the doctor may inject a substance into an intravenous (IV) line to help get a better image of your heart's function during your echocardiogram.
As with any medical procedure, always inform your doctor about any medicines you are taking, and ask whether you should or should not take your medications before the test. Restrictions for an echocardiogram are minimal. Most people can eat and return to their normal routine when the test is completed.
Preparing For Your Test
On the day of your test, wear a two-piece outfit. You may need to undress from the waist up and put on a short hospital gown. Echocardiograms may be performed with you sitting or lying down. The technician will place small pads (electrodes) on your chest. A small microphone-like device called a transducer will be coated with cool gel and placed on your chest to "bounce" ultrasound waves off your heart. The technician will move the transducer from place to place to produce different views of your heart in motion. At times you may be asked to exhale and hold your breath for a few seconds. A computer translates the waves into images that can be viewed on a monitor and recorded on paper for your doctor to examine later.
A thorough examination using echocardiography typically takes 30 to 45 minutes depending on the number of views and types of techniques used. Results may be different for patients who are obese or who have broad chests or chronic lung disease.
Many such tests are performed each year with a very low risk of complications. The risks are presumably higher in patients with severe heart disease. Still, no procedure is 100-percent risk-free. Your technician will ask you to sign a consent form before your test begins. Feel free to ask any questions about the procedure at this time.
You may be able to receive preliminary results before you leave. A complete interpretation may take several days. The information gained from an echocardiogram helps your doctor make an accurate diagnosis and develop a treatment plan that's best for you.
Also known as an exercise echocardiogram, this test combines an ultrasound study of the heart with an exercise test. This allows your doctor to learn more about how your heart functions when it works hard.
Normally, all areas of the heart muscle pump more vigorously during exercise. If an area of your heart muscle doesn't pump as it should, this can indicate that it is not receiving enough blood due to a blocked or narrowed artery.
As with any medical procedure, always let your doctor know what medicines you are taking and ask if you should take them before the test. Restrictions for an echocardiogram are minimal. Most people can eat and return to their normal routine when the test is completed.
On the day of your test, wear a two-piece outfit. You may need to undress from the waist up and put on a short hospital gown. The technician will place small pads (electrodes) on your chest.
First, a resting echocardiogram is performed. A small, microphone-like device called a transducer will be coated with cool gel and placed on your chest to "bounce" ultrasound waves off your heart. Next, the technician will have you walk for a few minutes on a treadmill, during which time your heart rate will be monitored. The third part of the test involves taking a second echocardiogram just after you stop exercising, but while your heart is still beating rapidly. Images of your heart before and after exercise are recorded on videotape for your doctor to compare.
During the exercise portion of the test, you should tell the technician if you feel discomfort in your chest, arm, or jaw, or if you experience shortness of breath, fatigue, dizziness or leg cramps.
Many such tests are performed each year with a very low risk of complications. The risks are presumably higher in patients with severe heart disease. Still, no procedure is 100-percent risk-free. Your technician will ask you to sign a consent form before your test begins. Feel free to ask any questions about the procedure at that time.
You may be able to receive preliminary results before you leave. If your test is positive, you will receive a cardiologist evaluation within 48 hour. A complete interpretation may take several days. The information gained from an echocardiogram helps your doctor make an accurate diagnosis and develop a treatment plan that's best for you.
Diagnosing Irregular Heartbeats
Particularly as we get older, we may notice our heart sometimes feels like it’s racing, jumping, or skipping beats. Heart palpitations, or irregular heartbeats, can range from benign to very serious. They can also be accompanied by shortness of breath, sweating, lightheadedness, or even passing out. An abnormal heart beat is an arrhythmia. A fast heartbeat is tachycardia. The most common irregular rhythm is atrial fibrillation, which causes poor blood flow. The most dangerous is ventricular tachycardia, which can be fatal.
The severity of the feeling doesn’t always indicate the severity of palpitations. A person with the most minimal symptom can have the worst arrhythmia, and vice-versa. That’s why it’s important to have any heart palpitations checked out by a physician.
The first step to evaluating a patient’s heart rhythm is a physical and history, along with an EKG exam. Next, the rhythm is captured using a portable monitor, which the patient wears for between two weeks to two months.
The new Zio™ monitor is only two and a half inches long, sticks to the patient’s body, and isn’t noticeable under clothing. Patients can even swim and shower. Previously, a Holter monitor--a medium sized-box with a shoulder strap and probes attached to the body-- was used.
Treatments for an arrhythmia may include avoiding caffeine and stimulants and a change in medications, but occasionally a patient needs an implantable device, such as a pacemaker or a defibrillator, or may even need a heart bypass operation.
Your esophagus -- the tube leading from your throat to your stomach -- is located directly behind your heart. Being so close to the heart, it is an ideal site from which to view the heart's action with an echo exam. Focusing ultrasound waves from this vantage point allows your doctor to see a close-up image of the heart as it beats, as the valves open and close, and as the blood flows in and out.
A Transesophageal Echocardiogram (TEE) is an especially useful exam for viewing the valves that separate the upper and lower chambers of the heart, and the valves between the lower chamber and the major arteries. Holes or defects between chambers can be seen clearly, and major blood vessels can be carefully studied.
TEE is often performed as an outpatient procedure in a hospital. Before your exam, you should not eat or drink anything for six to ten hours (small sips of water are usually okay). Your doctor will advise you about whether you should take your regularly prescribed medications prior to the exam.
For the procedure, you will be asked to lie on your left side. The doctor's assistant may spray your throat with an anesthetic, and will give you a sedative to help you relax. Your doctor may also give you an antibiotic to help prevent infection.
Your doctor will insert a tube about the diameter of your thumb down your throat and into your esophagus. You may feel the probe as it moves, but generally, this is not painful.
The ultrasound transducer is positioned in the esophagus just behind the heart. In the tip of the probe, the transducer sends out sound waves. Attached to the probe wire is a computerized analyzer which instantly creates an image of the reflected sound waves. This gives your doctor a very clear picture of your beating heart.
During the procedure, your heart rate, blood pressure, and breathing are carefully monitored. Occasionally, the doctor or assistant may find it necessary to clear secretions from your mouth. In some cases, patients are given supplemental oxygen during this procedure.
A TEE takes about thirty minutes. You should allow one to two hours from the time you arrive to the time your doctor releases you to go home.
- Have someone drive you home, and don't drive for 12 hours.
- Don't eat or drink for an hour, or until your throat is no longer numb.
- Use throat lozenges and small sips of cool liquids to ease any throat pain.
- Report unusual symptoms to your doctor.
Because TEE requires the insertion of a probe into the body, it is not without risk. The risk is small, however. In rare instances, complications can include breathing difficulty, abnormal heart rhythms, infection of heart valves, reaction to sedatives, and bleeding. In very rare cases, TEE may pierce the esophagus. To understand your particular risk, you should discuss it with your doctor.
For more information, please call the Heart Institute at 410-337-1216.