An electrocardiogram (ECG) is an important cardiac test that assesses the rhythm and electrical activity of your heart. It shows important information about your heart that can help your cardiologist assess your overall cardiac health and how well your heart is functioning. An ECG can also be used to diagnose or investigate a variety of heart conditions.
There are several different types of ECGs. The cardiologist will recommend the best ECG for you, depending on the symptoms you are experiencing, whether they suspect a specific heart condition and any previous cardiac testing you have undergone.
The most commonly used ECGs are:
· A Resting Electrocardiogram (ECG)
A resting ECG is carried out when you are lying down in a comfortable position and when your heart rate is at rest. To ensure that they are monitoring your resting heart, the cardiologist will ask you to lie down and relax for approximately 2 minutes before the test begins. A resting ECG shows the electrical signals that occur when the upper and lower chambers of your heart are contracting and relaxing.
A healthy heart will show a heart rate of between 60 and 100beats per minute (bpm) and will form a predictable pattern on the ECG monitor. If you have an irregular heartbeat, these signals will not match the expected pattern. The cardiologist will likely be able to determine the reasons why this is happening from the resting ECG, because many heart disorders create identifiable patterns, for example, each type of arrhythmia has its own distinct pattern.
· A Stress Electrocardiogram (ECG)
A stress ECG, sometimes called an exercise ECG or an exercise tolerance test (ETT), is carried out while you are exercising, usually on a treadmill or a stationary exercise bike. It assesses your heart’s electrical activity while it is under physiological stress and shows how well your heart works during physical activity. It is usually recommended if your symptoms are triggered by exercise or exertion.
Because exercise makes your heart pump faster and harder, this increases your coronary blood flow. A stress ECG assesses how well the blood flows through your coronary arteries, as well as your heart rate and electrical activity when you are exerting yourself. It is often used to diagnose coronary heart diseases.
· An ECG Holter Monitor
Sometimes called an ambulatory ECG, an ECG Holter monitor is usually recommended if your symptoms are unpredictable, occur irregularly and/or vary in length. A Holter monitor is a small portable ECG machine that you carry around with you for a specified amount of time (between 24 hours and 14 days).The machine will record your heart rate and rhythm continuously over this time to identify any irregularities, known as arrythmias. Because a Holter monitor assesses your heart rate, heart rhythm and the electrical activity of your heart over a period of time, it is more likely to detect an arrhythmia that occurs intermittently. A Holter monitor may be recommended if a previous ECG test presented as normal but you are experiencing concerning symptoms.
