ECG vs. Heart Rate Monitor: What’s The Difference?

If you need to track your heart rate, you need the most accurate and best way of doing so. Of course, if you are an athlete, keeping track of your vitals and heart rate is essential for your overall performance. Moreover, if you have various health conditions, you may also want to track your heart rate.

However, heart rate monitoring is performed in one of two ways. First, heart rate can be monitored using ECG or PPG.

ECG stands for electrocardiograph or electrocardiogram. PPG stands for photoplethysmogram or photoplethysmography. One is an electrical measurement, while the other is a visual measurement of your heart rate. We mention PPG because this is how most wrist-based heart rate monitors work. In addition, fitness trackers such as Fitbits usually always use PPG. Some newer models incorporate ECG. Today, we will do an ECG vs. heart rate monitor comparison to see how they work and compare.

ECG: The Basics

An ECG, or electrocardiograph, uses various sensors (electrodes) attached to the limbs and the chest. These electrodes feature sticky patches that adhere to the skin; wires connect them to monitors.

Every time your heart beats, an electrical signal is created, and the sensors pick up and monitor these impulses. A computer records this information and displays it in waves on paper or a monitor.

An ECG is one of the most accurate ways to monitor heart rate. This is why it is used in hospitals. It is also one of the easiest and fastest tests to monitor heart rate.

An electrocardiograph shows you how fast the heart is beating and the electrical impulses’ rhythm, timing, and strength. So not only does it tell you how fast your heart is beating, but also if it’s regularly beating and at full strength.

Heart Rate Monitors (PPG): The Basics

Then, there are heart rate monitors that you’d use for home-based monitoring. We’re talking about wrist-based monitors, such as Fitbit and other fitness trackers. This monitor type uses PPG or photoplethysmography.

This is also known as optical heart rate monitoring. PPG heart rate monitors use light-based technology to sense the blood flow rate. This monitor will have green LED lights on the bottom, directed at your wrist. This green light shines at and into your wrist and reflects off your blood.

Other sensors in the monitor pick up the reflected light. For example, there is more blood in your veins when your heart beats than at rest, which is what optical heart rate sensors pick up. It’s all about the amount of light that shines back from your veins or arteries.

Monitoring Heart Rate Using ECG and PPG

Let’s look at how both these heart rate monitoring methods work. First is the ECG or electrocardiogram. This is best done by attaching electrodes to the chest. It directly monitors the heart’s electrical activity, so it’s best to take measurements close to the heart. This is why electrodes are attached to the chest.

PPG, or optical heart rate monitoring, functions a little differently. This heart rate monitoring is usually best done at the wrist, so most home-based fitness trackers come as small watches.

However, this type of heart rate monitoring can technically be done virtually anywhere in the body, including your wrist, earlobe, finger, temple, or elsewhere. However, most home-based heart rate monitoring will use optical or PPG sensors.

However, as the years go on, there are increasingly more home-based heart rate monitors that incorporate ECGs. Now, most fitness trackers that have PPG also have ECGs. Many modern models use both methods.

ECG vs. Heart Rate Monitor

ECG vs. Optical Heart Rate Monitors: Main Differences to Consider

Perhaps the most significant difference concerns accuracy. ECG is the most popular method of monitoring heart rate, particularly in hospitals and professional settings, because it is generally 100% accurate.

The readings are taken directly from the chest, right above the heart, so the measurement tends to be highly accurate. In addition, it’s precise, so it can create a graph, otherwise known as a cardiograph, which displays your heart rate and additional information about the condition of your heart.

This includes how strong your heart is beating and whether or not it is regularly beating. Although reading an ECG is not overly easy, it is highly detailed, in-depth, and provides information that can be deciphered by professionals.

On the other hand, PPG, or optical heart rate sensors, are not entirely as accurate; if you are sitting down and sitting still, they’re relatively accurate.

However, this depends on the quality of the heart rate monitor. Moreover, there can be accuracy issues due to movement. For example, if you don’t wear the device right or move around a lot, it can cause errors in readings.

Moreover, you should consider ease of monitoring. For instance, you need the chest strap and electrodes with an ECG. Getting an accurate ECG reading is impossible if you don’t have them.

Therefore, if you want to measure your heart rate at home with an ECG, you must attach the electrodes every time. Therefore, an ECG is not the best to use if you are always on the go or want to monitor your heart rate for sports-related activities.

Most athletes will use PPG or optical heart rate monitoring. It might not be as accurate. However, this method does not require electrodes, just the wrist-based device, so it’s much easier. Using PPG or an optical heart rate monitor, you can track your heart rate throughout the day without wearing electrodes.

Final Thoughts

Both ECG and PPG are effective ways of monitoring heart rate. However, there are differences between the two regarding accuracy and functionality.