Echocardiogram
What is an Echocardiogram?
An echocardiogram is a test utilising sound waves to create a moving picture of the heart. This allows your doctor to evaluate how your heart is beating and pumping blood, helping determine whether any abnormalities in your heart muscle or heart valves are present, as well as your risk for heart disease.
Why Do I Need an Echocardiogram?
Your doctor may suggest an echocardiogram if he or she suspects abnormalities with the valves or chambers of your heart, or your heart’s ability to pump. An echocardiogram can also be used to detect congenital heart defects in unborn babies.
The different types of echocardiograms include:
- TRANSTHORACIC ECHOCARDIOGRAM – this is the most common, non-invasive echocardiogram. A sonographer spreads gel over your chest and moves a transducer to different locations on your chest or abdominal wall. The transducer records the sound wave echoes your heart produces. These waves are converted by a computer into moving images on a monitor.
- STRESS ECHOCARDIOGRAM – this involves an echocardiogram both before and after your heart is stressed through exercise or by injecting a medicine that makes your heart beat harder and faster. This test is usually conducted to assess whether decreased blood flow to your heart is present.
- TRANSESOPHAGEAL ECHOCARDIOGRAM – this test is generally recommended when it is difficult to get clear images of your heart with a standard echocardiogram. A probe is passed down the esophagus instead of being moved over the outside of the chest wall. Clearer pictures of the heart are produced as the probe is located closer to the heart and because the lungs and bones of the chest wall do not block the sound waves produced by the probe. A sedative and anesthetic applied to the throat are used to make you comfortable during the test.
- DOPPLER ECHOCARDIOGRAM – this test is used to see how blood flows through the heart chambers, heart valves and blood vessels. The movement of the blood reflects sound waves to a transducer. The ultrasound computer than measures the direction and speed of the blood flowing through your heart and blood vessels. Doppler techniques are commonly used for transthoracic and transeophageal echocardiograms.
What are the risks?
The risks associated with a standard transthoracic echocardiogram are minimal. Some discomfort may be felt when the electrodes (similar to an adhesive bandage) attached to your body are removed.
For transeophageal echocardiogram, some soreness in the throat may be experienced a few hours afterwards. Your oxygen levels may be monitored during the test to check for any breathing problems caused by the sedation medication.
For stress echocardiograms, either the exercise or medication may temporarily cause an irregular heartbeat. It is rare for serious complications to occur as a result.
What do I need to prepare before the test?
Transthoracic echocardiogram and Doppler echocardiogram
No special preparation is required for either test.
Stress echocardiogram
Avoid eating heavily for a few hours before the test. This will help prevent nausea which can occur while exercising with a full stomach or from the dobutamine injection.
For the exercise component of the test, bring flat, comfortable shoes as well as loose lightweight shorts or sweatpants.
Transeophageal echocardiogram
Avoid food and drink for at least 6 hours before the test.
If you use dentures or dental prostheses, you may need to remove them before the test.
Be sure to arrange for someone to pick you up after the test, as driving should be avoided for at least 12 hours after the procedure.
Before an echocardiogram, you may be asked to sign a consent form. Speak with your doctor regarding any concerns you may have about the need for the test, its risks, how it will be done, or what the results may indicate.
What will the test feel like?
During the test you will be asked to disrobe from the waist up and lie on an examination table or bed on your back. Electrodes will be placed on your body to help detect and conduct the electrical currents of your heart.
For a transeophageal echocardiogram, a spray or gel will be used to numb your throat, as well as a sedative to help you relax.
To view the images better, the technician will dim the lights. A “whooshing” sound may be heard throughout the test. This is the machine recording the blood flowing throughout the heart.
The test generally takes less than an hour, but this can vary depending on your condition. For transthoracic echocardiograms, you may be asked to breathe in a certain way or to roll onto your left side. At times the transducer may be held uncomfortably firmly against your chest. This is sometimes necessary to produce the best images of your heart.
What happens after the procedure?
If the test results are normal, no further testing may be needed. If the results are of concern, you may be referred to a cardiologist for further assessment. Treatment will vary depending upon what is found during the exam and your specific signs and symptoms. Sometimes your doctor may suggest you undergo a repeat echocardiogram in several months.
The Results
The results of the echocardiogram can reveal many aspects of your heart health including:
- HEART SIZE: weakened or damaged heart valves, high blood pressure or other diseases can cause your heart chambers to enlarge. Your doctor will utilize the echocardiogram to determine the need for treatment or monitor treatment effectiveness.
- PUMPING STRENGTH: the echocardiogram can assist your doctor in determining your heart’s pumping strength. Specific measurements may include the percentage of blood that’s pumped out of a filled ventricle with each heartbeat (ejection fraction) or the volume of blood pumped by the heart in one minute (cardiac output). If insufficient blood is being pumped around the body, there is a risk of heart failure.
- HEART MUSCLE DAMAGE: the echocardiogram will help your doctor determine whether all parts of the heart wall are contributing equally to your heart’s pumping activity. Weakness can be as a result of a heart attack or due to insufficient oxygen. It may also indicate coronary artery disease or various other conditions.
- VALVE PROBLEMS: the echocardiogram can show how your heart valves move as your heart beats. Your doctor can determine if the valves open wide enough for adequate blood flow or close fully to prevent blood leakage. Abnormal blood flow patterns and conditions such as aortic valve stenosis — when the heart's aortic valve is narrowed — can be detected as well.
- HEART DEFECTS: an echocardiogram can detect many types of heart defects, which include, heart chamber problems, abnormal connections between the heart and major blood vessels, and complex heart defects that are present at birth. Echocardiograms can even be used for monitoring a baby’s heart development before birth.
Electrocardiogram (ECG)
What is an ECG?
An electrocardiogram (ECG) is a test that records the electrical activity of the heart. It is a non-invasive, painless test.
Why do I need an ECG?
Your doctor may suggest an ECG to measure:
- Any damage to the heart;
- How fast your heart is beating and whether it is beating normally;
- The effects of drugs or devices used to control the heart (e.g. pacemaker)
- The size and position of your heart chambers
An ECG is also useful for determining whether a person has heart disease. Your doctor may request this test if you complain of chest pain or palpitations.
The test may be included as part of a routine examination in patients over the age of 40.
What do I need to prepare before the test?
It is important to inform your doctor of all non-prescription and prescription medicines you take, as some medicines can distort the results of your ECG. For heart medicines, your doctor will inform you how to take your medicines before the test.
All jewellery should be removed during the test. Men usually perform the test bare-chested, whilst women may wear a bra, T-shirt or gown. A cloth or paper covering will also be provided, as stockings should be taken off.
What are the risks?
An ECG is a safe procedure. Minor discomfort may be experienced only when electrodes are removed, similar to the removal of a band-aid. In some rare cases, electrodes may cause redness or swelling of the skin.
When an ECG is performed during a stress test, the exercise or medication that mimics the effects of exercise, may cause irregular heartbeats. This side effect is caused by the exercise or medication, not the ECG itself.
The risk of electrocution during an ECG is nil. Electrodes placed on your body only record the electrical activity of your heart. They do not emit electricity.
What to expect during the test
The test will require you to lie down. Electrodes will then be attached to your arms, legs and chest with a gel that helps detect and conduct electrical currents of your heart. If hair is present on parts of the body where the electrodes will be placed, your technician may need to shave the hair so that the electrodes stick to the skin.
The number of patches used may vary.
You usually need to remain still, and you may be asked to hold your breath for short periods during the procedure. It is important to be relaxed and relatively warm during ECG recording. Any movement, including muscle tremors such as shivering, can alter the results.
The electrodes are connected by wires to a machine that converts the electrical signals from the heart into wavy lines, which are printed on paper and reviewed by the doctor.
Sometimes this test is done while you are exercising or under minimal stress to monitor changes in the heart. This type of ECG is often called a stress test.
If you have an intermittent heartbeat irregularity that may not be captured during your ECG, your doctor may recommend another type of ECG:
- HOLTER MONITOR – also known as an ambulatory ECG monitor, a Holter monitor records your heart rhythms for an entire 24-hour period. Wires from electrodes on your chest go to a battery-operated recording device carried in your pocket or worn on a belt or shoulder strap. Whilst wearing the device, you will be asked to keep a diary of your activities and symptoms. Your doctor will compare the diary with the electrical recordings to determine the cause of your symptoms.
- EVENT RECORDING – if the symptoms are infrequent, your doctor may suggest this device. It is similar to a Holter monitor, except that it allows you to record an ECG just when the symptoms occur.
What happens after the procedure?
If your test results are normal, no further testing may be needed. If abnormalities are found, a repeat ECG or other diagnostic test, such as an echocardiogram may be required. Treatment will depend on the causes of your signs and symptoms.
The Results
A consistent, even heart rhythm and a heart rate between 50 and 100 beats a minute is considered healthy. Variations provide clues about your heart health including:
- HEART RHYTHM: when the heart’s electrical system malfunctions, an ECG can help your doctor identify an unusually fast heartbeat (tachycardia), an unusually slow heartbeat (bradycardia) or other heart rhythm irregularities (arrhythmias). In other cases, medications such as beta blockers, psychotropic drugs or amphetamines can trigger arrhythmias.
- HEART ATTACK: an ECG can often identify evidence of a past heart attack or one that’s in progress. The ECG patterns may also indicate which part of your heart has been damaged, as well as the general extent of the damage.
- INSUFFICIENT BLOOD AND OXYGEN SUPPLY TO THE HEART: an ECG conducted whilst having symptoms can help your doctor determine whether the chest pain is caused by inadequate blood flow to the heart muscle.
- STRUCTURAL ABNORMALITIES: an ECG can provide clues about enlargement of the chambers or walls of the heart, heart defects and various other health problems.
Stress Testing
What is a Stress Test?
A stress test helps determine how well your heart works under stress. The test involves exercise on either a treadmill or bicycle. The harder your body works, the more oxygen it needs, and the harder your heart needs to pump. By showing whether the blood supply is reduced in the arteries that supply the heart, it will help your doctor determine whether you have coronary artery disease, and if so, the severity.
Why Do I Need a Stress Test?
Your doctor may recommend a stress test to:
- diagnose coronary artery disease;
- diagnose a complaint relating to chest pain, shortness of breath or light-headedness;
- determine a safe level of exercise;
- determine the effectiveness of procedures done to improve coronary artery circulation in patients with coronary artery disease; and
- predict the risk of dangerous heart-related conditions such as heart attack
What Do I Need to Prepare Before the Stress Test?
- Stress tests generally take about 1 hour, however, allow for 2 hours just to be on the safe side.
- Bring walking shoes and loose-fitting clothing.
- Avoid solid foods for 4 hours before the test
- You may drink water, however avoid caffeinated drinks (i.e. regular and decaf coffee, tea, chocolate, soft drink)
- Ask your doctor if you should take your medicines the morning of the test. If so, take with sips of water only.
What to Expect During the Test?
A technician is always present throughout the test to closely monitor your wellbeing.
Sticky patches called electrodes are attached to your chest, arms and legs. The electrodes record the electrical activity of your heart. Called an EKG (electrocardiogram), the recording will show how fast your heart beats, its rhythm (steady or irregular), as well as the strength and timing of electrical signals as they pass through each part of the heart.
A blood pressure cuff will be wrapped around your arm to monitor your blood pressure during the test. In addition, you may be asked to breathe into a special tube so the gases you breathe out can be monitored.
Once the test starts, the exercise level will get harder. However, you can stop at any time, if you feel the exercise is too much. At completion, you will be able to return to normal activities.
What is Monitored During the Test?
- Your heart rate
- Your breathing
- Your blood pressure
- Your electrocardiogram (ECG or EKG)
- How tired you feel
What are the Risks?
There is very little risk - no more than if you walked fast or jogged up a big hill. At all times, a doctor will be available in the event anything unusual occurs during the test.
What are the Warning Signs of Heart Attack?
Some heart attacks can be intense and come without warning, however, in most cases, it starts slowly with mild pain or discomfort. Common symptoms include:
- Chest discomfort
- Discomfort in other areas of the upper body
- Shortness of breath
- Cold sweat break out
- Nausea or light-headedness
What are the Warning Signs of Stroke?
- Sudden weakness or numbness of the face, arm or leg, especially on one side of the body
- Sudden confusion, trouble speaking or understanding
- Sudden trouble seeing in one or both eyes
- Sudden trouble walking, dizziness, loss of balance or coordination
- Sudden, severe headache with no known cause
Holter Monitors
What is a Holter Monitor?
A Holter monitor is a device that continuously records the heart rhythms. It is usually worn for 24-48 hours during normal activity. The device is also known as ambulatory electrocardiography (ECG).
Why do I need a Holter Monitor?
Your doctor may suggest the monitor be used after a heart attack to identify heart rhythm problems and/or when starting a new heart medicine.
The device may also be used to diagnose:
- Atrial fibrillation/flutter;
- Multifocal atrial tachycardia;
- Palpitations;
- Paroxysmal supraventricular tachycardia;
- Reasons for fainting;
- Slow heart rate (bradycardia)
- Ventricular tachycardia
What do I need to Prepare Before the Test?
No special preparation is needed before the test. Your doctor or technician will start the monitor. In the event of electrodes falling off or becoming loose, you will be taught how to reattach the electrodes.
Advise your doctor if you are allergic to any tape or other adhesives.
Have your shower or bath before starting the test, as you will not be able to do so whilst wearing the monitor.
While wearing the device, avoid:
- Electric blankets;
- High-voltage areas;
- Magnets; and
- Metal detectors.
Keeping a diary of your symptoms is important. It should include the date, time of day, type and duration of symptoms.
What will the Test Feel Like?
The test is painless and non-invasive. However, some people may need their chest shaved so the electrodes can stick.
The monitor must be kept close to your body. This can cause discomfort for some people when going to sleep.
Are There Any Risks?
There are no risks associated with the test. However, you should avoid getting the monitor wet.
The Results
A normal result is when there is no significant change in heart rhythm or pattern.
Abnormal results may include various arrhythmias. This may be because the heart is not getting enough oxygen.
The monitor may also detect conduction block, a condition in which the atrial electrical activity is either delayed or does not continue into the ventricles of the heart.