ECG vs Echo: Key Differences to Guide Your Heart Health Choices

Your heart's electrical rhythm is a powerful, complex organ, and keeping it healthy should be your top priority. The Echocardiogram (Echo) and the Electrocardiogram (ECG or EKG) are two of the most frequently used and important tests. Both tests are important, but they serve very different purposes despite having similar names.

You’re not the only one who has been puzzled over the distinction between an ECG and an Echo. This guide will clear the confusion surrounding these common diagnostic tests, their purpose, mechanism and the difference between electrocardiogram and echo, particularly in diagnosing arrhythmias and irregular heart rhythms, which is the reason why one test is selected by your doctor instead of the other or in most cases, both. Being aware of this difference will enable you to experience symptoms as a full-fledged consumer of your own health, whether it is the ability to identify the symptoms or to communicate the results with your cardiologist.

An Electrocardiogram (ECG) is a fast, painless, and non-invasive procedure that measures the electrical activity of your heart. You can imagine it as an electric picture of your beating heart. When the heart beats, the electric pulse goes through your heart, and this makes the heart contract and pump the blood. These impulses create voltage changes which are recorded as waves.

Some small stickers referred to as electrodes are placed on your chest, arms and legs by a technician. These electrodes are attached to an ECG machine. They pick up electrical variations that occur whenever the heart muscle depolarises with each beat of the heart. This information is recorded by the machine, which traces it on paper. The whole procedure is just 5-10 minutes while you are lying down.

• Arrhythmias: Irregular heartbeats (too slow, too fast or irregular).

• Coronary Artery Disease (CAD): Reduced blood flow due to narrowed or blocked heart arteries, which may lead to a heart attack.

• Heart Attack: Signs of an existing or previous coronary attack.

• Other Issues: Changes in chamber size or problems with electrical conduction.

An Echocardiogram (Echo) is an ultrasound of the heart that emits sound waves . It employs the high-frequency sound waves (ultrasound) to produce detailed moving images of your heart’s structure and function.

A sonographer rubs a special gel on your chest and then runs an ultrasound probe known as a transducer. Sound waves produced by the transducer ricochet off your heart structures. The transducer picks up the returning "echoes" and transforms them into real-time images on a monitor. This helps the doctor see the heart beating and blood flow using Doppler ultrasound.

An echocardiogram test will give a great deal of information on the anatomy and functioning of the heart, making it an important imaging test:

• Heart Valve Problems: Evaluation of leaking (regurgitation) or constriction (stenosis) of valves.

• Pumping Strength: Determining the percentage of the amount of blood that is pumped out of the heart.

• Chamber Size: Examining whether the chambers are enlarged or the heart walls are thick.

• Congenital Heart Defects: It happens due to birth defects.

Different tests can be used to assess the heart, which yields different kinds of information. There are two most commonly used diagnostic tools, namely the Electrocardiogram (ECG) and the Echocardiography (Echo). 

ECG is used to capture the electrical activity of the heart and help detect rhythm and conduction abnormalities, whereas echocardiography (Echo) is used to examine the structure and functionality of the heart, including chambers, valves, and cardiac circulation. To correctly diagnose and treat cardiac conditions, it is necessary to understand the distinctions between the two tests to assess the patient's heart health .

The ECG (Electrocardiogram) measures the electrical signals of the heart, capturing information on rhythm, conduction pathways, and ischemia or infarction. On the contrary, an echocardiogram (Echo) involves the use of high-frequency sound waves to produce detailed images while examining the structural and functional features of the heart, such as the chambers, valves, and circulation patterns.

ECG is used to evaluate the electrical causes of chest discomfort, not to detect the symptom itself. It provides a snapshot of the electrical impulse and activity of the heart. Echo is, however, used to assess anatomical and functional features, including the size of the chambers, wall movement, valves, heart valve function, ejection fraction, cardiac defects, and pericardial effusion. Basically, ECG is concerned with the electrical health of the heart muscle and can help detect conditions like atrial fibrillation, while Echo is focused on the mechanical and structural health of the heart.

An ECG is a painless test that is not invasive, fast and easy as it only needs electrodes on the chest, arms, and legs. It can be finished within several minutes. Echo helps to generate real-time images of the heart’s structure and blood flow. Echo examination is more lengthy and can be 15-45 minutes in duration, which is important for monitoring heart health,  and it also needs expert equipment and operators.

An ECG can give instant electrical data, e.g. heart rate, heart rhythm and can help to detect abnormal heart rhythms, but not heart structure or blood flow. Echo offers real-time imaging of the anatomy and functioning of the heart, enabling clinicians to examine how anxiety alters the movement of valves, wall thickness, chamber size, the patterns of blood flow through the heart, and the potential presence of blood clots by Doppler imaging.

There is a limited capability of ECG to determine the structural or functional heart cases, and also ECG cannot measure the ejection fraction or valve functioning. Echo, although good in cases of anatomical analyses, is not able to diagnose electrical disturbances/arrhythmias without simultaneous correlation with ECG.

ECG is usually employed in the presence of palpitations, syncope, suspected myocardial infarction or heart block when electrical irregularities are the suspected. Echo is the choice in assessing heart failure, heart defect, structural heart defect, pericardial effusion, and general cardiac performance.

Altogether, ECG provides an electrical snapshot of the heart, whereas Echo provides a structural and functional snapshot.

Here’s a recommended comparison table:

The decision on whether to use a 2D Echocardiogram (Echo) or an Electrocardiogram (ECG) would mostly rely on the symptoms of the patient, the suspected heart condition, and the kind of information a clinician requires. 

An ECG is a non-invasive, fast test which measures electrical activity in the heart. It is also useful in the diagnosis of arrhythmias, conduction abnormalities, heart blocks, and myocardial ischemia or infarction.

ECG is commonly the first line of investigation in patients presenting with palpitations, syncope, chest pain, or acute coronary syndrome. Its key benefits include speed, simplicity and low cost, but it will not give any information regarding heart structure, the work of the valves and the efficiency of pumping.

The 2D Echocardiogram, on the other hand, involves the use of ultrasound to perceive the anatomy of the heart and determine its performance. The test is more desirable to diagnose valvular abnormalities, wall motion defects, congenital heart disease, pericardial effusion, and cardiac functioning as a whole with ejection fraction. The Doppler imaging can also be used by the Echo to measure blood flow in the valves and between chambers. 

Clinical trials involving ECG and 2D Echocardiography have demonstrated that the use of ECG and 2D Echocardiography is more likely to improve the accurate diagnosis of cardiac diseases by up to 30-40 per cent over the use of ECG alone. 

This shows that the tests are complementary, and ECG can identify the electrical abnormalities, and the echo test can help to give a structural and functional view, and the result is a more thorough assessment of heart health.

Prices of cardiac tests in India are unevenly distributed based on such aspects as the kind of facility (government or privately run), location (metro or small towns), and the test complexity.