What is an ECG?

An electrocardiogram (ECG or EKG) is a simple, non-invasive test that measures the electrical activity of the heart. This test is crucial for diagnosing and monitoring various heart conditions. In Australia, where cardiovascular diseases are a leading cause of death, understanding the role of an ECG can help in the prevention and early detection of heart issues.

An electrocardiogram is a medical test that records the electrical signals generated by the heart as it beats. These signals are captured through electrodes placed on the skin, typically on the chest, arms, and legs. The resulting data is displayed as a graph, known as an electrocardiogram, which healthcare professionals analyze to assess heart health.

ECGs are often used by doctors to help them diagnose heart-related issues like coronary heart disease, arrhythmias, cardiomyopathy and heart attacks. They can also be used as part of a general check-up and to monitor patients when they’re undergoing a range of medical procedures. 

Because electrocardiograms are so useful, they’re one of the most common medical tests used around the world. To help you understand exactly what an ECG is and what it is used for, we’re taking a closer look at the procedure, the equipment needed and the benefits of an ECG.

The Importance of Regular Heart Checks in Australia

Heart disease remains one of the leading causes of death and illness in Australia, affecting thousands of Australians every year. Regular heart checks, including electrocardiograms (ECGs), play a crucial role in preventing and managing heart-related conditions. 

One of the primary benefits of regular heart checks is the early detection of heart conditions. Many heart diseases, such as coronary artery disease and arrhythmias, may not show obvious symptoms in their early stages. An ECG can reveal abnormalities in heart function that might otherwise go unnoticed. Early detection allows for timely intervention, which can prevent serious complications, such as heart attacks or strokes.

The Australian government, along with various health organizations, has implemented several programs and initiatives to promote heart health and encourage regular check-ups. Campaigns like the Heart Foundation's "Check Your Heart" initiative aim to raise awareness about the importance of heart health and provide resources for Australians to get their hearts checked. These programs are instrumental in reducing the burden of heart disease on the healthcare system and improving public health outcomes.

When Should You Get a Heart Check?

Healthcare professionals recommend that adults, especially those over the age of 45, should have regular heart checks. For those with risk factors or existing heart conditions, more frequent monitoring may be necessary. It's advisable to consult with a healthcare provider to determine the appropriate schedule for heart checks based on individual health profiles and risk factors.

What is an ECG Test?

An ECG test is a type of medical procedure that measures the electrical activity and rhythm of a patient’s heart. ECGs are often carried out in medical settings in order to monitor patients and aid diagnoses. They are also often used by paramedics and other first aid providers when working on a person experiencing a heart attack or arrhythmia.

A number of good quality defibrillators come with built in ECGs. This allows first aiders to properly assess the patient’s condition and provide the most appropriate level of care.

The results of an ECG are either printed on specialist ECG paper or displayed on a screen. In general, some medical training is required in order to accurately read and interpret the results of an ECG test.  

 

What is an ECG Scan?

An ECG scan is another term for an ECG test. There are three main types of ECG test: resting, ambulatory and exercise stress test.

A resting ECG is carried out when a patient is still and lying down. It normally takes around 10-15 minutes to complete and is used to check the resting rhythm of the heart.

An ambulatory ECG is used to monitor a patient’s heart activity as they complete a variety of tasks. It’s often carried out using a portable device that is worn by the patient for a period of 24 or 48 hours. These types of ECGs can highlight occasional irregular activity and show how the heart copes with gentle exercise and daily living.

As the name suggests, an exercise stress test is carried out when the patient is undergoing more strenuous physical activity. Patients are often asked to ride an exercise bike, run on a treadmill or take a rapid walk for a period of around 30 minutes while the test is underway. The results of an exercise stress test show how the heart copes with this increased physical activity.

What is an ECG and What Can it Tell You?

ECGs carried out on healthy hearts have a characteristic shape. Any deviation in this pattern can indicate that there is something wrong with the heart or with the blood vessels that serve it.

If irregular activity is noted on an ECG, it could mean that there is damage to the heart muscle or the vessels that surround the heart, or that the patient is experiencing an irregular heartbeat. In all cases, further investigation would be required in order to accurately diagnose the condition and treat the patient.  

What is an ECG Machine?

An ECG machine is the main piece of equipment required to carry out an ECG test. The machine itself is normally fairly lightweight and features a screen or printer that displays or prints test results. The ECG machine is attached to the patient via a series of cables and sensors. These ECG leads allow the machine to accurately measure the heart’s rhythm and electrical activity.

Because ECGs measure the activity of the heart, it’s important that the patient remains still for the duration of the test. If the patient moves around too much, the test may be inaccurate and the leads may become disconnected. In general, patients undergoing ECGs will be asked to lie on a bed until the test is complete.

What is an ECG Used For?

There are a number of reasons a doctor might ask for an ECG to be carried out. A patient will often have an ECG if they’re undergoing a general check up or if they’re experiencing one of the following symptoms:

• Chest pain
• Shortness of breath
• Dizziness
• Fainting
• Fast or irregular heartbeat (palpitations)

A doctor may also recommend an ECG for people who are at increased risk of developing heart disease. For example, those with a family history of heart disease, smokers, diabetics and people with high blood pressure, obesity and high cholesterol.

What is the Difference Between an EKG and an ECG?

When you begin researching ECGs, you’ll often come across the term ‘EKG’ as well. This can be confusing, but it’s important to understand that an ECG and an EKG are actually exactly the same. An EKG is simply another term for an ECG test.  

What Does an ECG Measure?

ECG tests have been specially developed to measure the electrical activity of the heart. If a patient has damaged heart muscle or diseased blood vessels, they will affect the shape of the ECG and indicate to doctors that further tests are required.

Following an irregular ECG, a patient might be sent for a chest x-ray, an echocardiogram (an ultrasound of the heart), an MRI scan or blood tests. These investigations will help the doctor to get a clearer picture of the heart and identify the exact cause of the irregular ECG. 

What are External Factors Affecting ECG Results?

Electrical Interference

• The presence of electrical devices, such as mobile phones, can cause interference.
• Being in an environment with high electromagnetic activity, such as near large machinery or medical equipment, can affect the ECG readings.

Electrode Placement

• If the electrodes are not placed correctly on the body, it can lead to inaccurate readings.
• Poor contact between the electrodes and the skin, often due to oily or sweaty skin, can disrupt the signal.

What are Patient-Related Factors?

Movement and Muscle Activity

• Any movement during the test, such as talking, coughing, or shifting positions, can cause artifacts in the ECG recording.
• Tensing muscles or shivering can also introduce noise into the ECG trace.

Skin Conditions

• Conditions like eczema, dermatitis, or excessive body hair can impede proper electrode adhesion, affecting the signal quality.

What are Patient Conditions that may affect the results?

Electrolyte Imbalances

• High or low levels of potassium in the blood can alter the ECG waveform, as potassium is crucial for cardiac electrical activity.
• Abnormal levels of these electrolytes can also affect heart function and ECG results.

Heart Conditions

• Irregular heart rhythms can cause inconsistent ECG readings.
• Scarring from a previous heart attack or surgery can affect the electrical signals of the heart.

Medications

• Medications used to treat heart conditions, such as beta-blockers or antiarrhythmic drugs, can alter the ECG pattern.
• Non-cardiac medications, including some antidepressants and antipsychotics, can also impact ECG results.

Substances

• Consumption of caffeine or nicotine before the test can increase heart rate and affect the ECG.
• Alcohol and recreational drugs can significantly alter heart rhythms and ECG readings.

Stress and Anxiety

• Stress, anxiety, or panic attacks can increase heart rate and cause changes in the ECG.
• Physical exertion before the test can elevate heart rate and affect the results.

Find out more about ECGs, browse our collection of high quality ECG machines and accessories or learn about our other specially selected medical products by exploring the Medshop site today. 

Author: Steven John Cumper, B.App.SC. (Osteo.), M.Ost., is a businessman with a strong foundation in biomedical science and osteopathic medicine, who founded and led Medshop to international success, culminating in its acquisition by the Bunzl Group in September 2021, where he continues to serve as Managing Director (Medshop Group).