ECG, SpO2 and Blood Pressure - How Modern
Smartwatches Support Cardiovascular Health

Reading duration: Approximately 8 minutes

Published: 11/10/2024  |  Last Edited:14/10/2024

Prof. Dr David Duncker

Prof. Dr David Duncker is a cardiologist and electrophysiologist and heads the Hannover Heart Rhythm Centre at the Department of Cardiology and Angiology at Hannover Medical School. He was a member of the EHRA Young EP Committee 2018-2020, was an EHRA Board Member and Chair of the EHRA e-Communications Committee 2020-2022 and the EHRA Digital Medicine and e-Communications Committee 2022-2024. He is currently a member of the EHRA Board and Chair of the EHRA Digital and
mHealth Committee 2024-2026.

The health of the cardiovascular system is an essential building block for our general well-being and a high quality of life. Cardiovascular diseases are the most common cause of death worldwide and, according to the World Health Organisation (WHO), are responsible for around 31% of global deaths.

Cardiovascular diseases such as high blood pressure, coronary heart disease (coronary artery disease and heart attacks) and heart failure (cardiac insufficiency) not only significantly reduce quality of life, but also cause high costs for the healthcare system.

Monitoring parameters such as blood pressure, oxygen saturation (SpO2), heart rate and electrocardiogram (ECG) in everyday life with a smartwatch such as the HUAWEI WATCH D2 offers a valuable opportunity to keep an eye on cardiovascular health.

In this article

Cardiovascular Monitoring - How Important is it?

ECG Monitoring

Measurement of Oxygen Saturation

Blood Pressure Monitoring

Conclusion: Smartwatches like the HUAWEI WATCH D2 Offer a Holistic Approach to Cardiovascular Health

The HUAWEI WATCH D2 measures various health parameters such as ECG, oxygen saturation, and blood pressure. This makes it possible to get a comprehensive overview of your health and integrate specific health data into your personal healthcare journey.

Cardiovascular Monitoring - How Important is it?

Very important! Cardiovascular health influences almost all areas of physical well-being. In the normal cardiovascular system, blood is pumped through the body by the heart and supplies organs and tissues with oxygen and important nutrients.

Good cardiovascular health is crucial for preventing chronic diseases and maintaining an active lifestyle.

Good to know - These are the most
common cardiovascular diseases:


- High blood pressure (arterial hypertension):
Permanently high blood pressure levels lead to heart attacks, dementia, strokes and arteriosclerosis, among other things.

- Coronary heart disease: narrowing or occlusion of the coronary arteries can lead to heart attacks or cardiac insufficiency, among other things.

- Cardiac arrhythmia:
Irregularities in the heart rhythm, such as atrial fibrillation, can lead to symptoms and increase the risk of stroke.

Cardiovascular monitoring can help in early detection and better management of high blood pressure and its associated risks, which can enable medical professionals to initiate specific therapies or adjust existing ones in good time.

Modern digital monitoring options enable early detection. With its numerous health functions, the HUAWEI WATCH D2 offers an easy way to integrate cardiovascular monitoring into everyday life.

ECG, SpO2, blood pressure and other health parameters can all be recorded, and values exhibited on the HUAWEI Health App. The watch guides the user through the measurement process and gives clear instructions on how to position themselves correctly and what to look out for (e.g. don't move, don't talk) to ensure reliable and smooth measurements.

The following parameters can be measured with the HUAWEI WATCH D2:
• Average heart rate
• Blood pressure
• Blood oxygen level
• Stress
• Skin temperature
• ECG
• Arterial stiffness

In the following section, I will go into more detail about the ECG function, blood pressure and oxygen content in the blood.

ECG Monitoring

The electrocardiogram (ECG for short) measures the electrical activity of the heart. It provides important information about the heart rate, the heart rhythm and sometimes also the presence of heart or other diseases.

ECG Measurement with the Smartwatch

In the past, recording an ECG was mainly possible in hospitals and doctors' surgeries, but digital tools such as smartwatches now make it possible to record an ECG outside of medical institutions [1].

Digital devices with an ECG function, such as smartwatches and special single-channel ECGs that can be paired with a smartphone, enable users to track their heart rhythm or heart rate and recognise possible irregularities.

Some devices can even analyse the heart rhythm independently and issue a warning in the event of irregularities or recommend an additional ECG.


This can be particularly helpful in detecting atrial fibrillation in certain population groups to enable early diagnosis. The recently published guidelines of the European Society of Cardiology for the treatment of atrial fibrillation (2024) [2], for example, recommend population-based screening for atrial fibrillation in people aged 75 and over or from the age of 65 if additional risk factors are also present.

The relevant risk factors include:
• Heart failure
• High blood pressure
• Older age
• Diabetes mellitus
• Stroke
• Vascular diseases

In addition to detecting atrial fibrillation, measuring heart rate variability can also be helpful as it serves as an indicator of stress levels and the health of the autonomic nervous system

ECG Measurements with Digital Devices - The Advantages:

✅ User friendliness
✅ Wide availability
✅ Possibility of continuous measurement.

Limitations lie in the accuracy and the dependence on correct application by the user.

Measurement of Oxygen Saturation


Oxygen saturation in the blood (SpO2) indicates the proportion of haemoglobin saturated with oxygen and is an indicator of lung and cardiovascular health. Normally, SpO2 values are between 95% and 100%. Deviations, especially values below 90%, can indicate diseases and critical conditions such as sleep apnoea or chronic obstructive pulmonary disease.

Monitoring SpO2 values can be helpful in chronic or acute respiratory diseases, for example, where oxygen uptake is impaired. Especially during the COVID pandemic, oxygen saturation was a parameter that could provide an indication of the severity of lung impairment and was used in some situations to assess the need for hospital treatment. Digital devices such as smartwatches use infrared light to measure oxygen saturation and offer a simple way of continuous monitoring.

Blood Pressure Monitoring

Blood pressure is a key parameter of cardiovascular health. According to the current guidelines of the European Society of Cardiology 2024, a non-elevated blood pressure is below 120/70 mmHg [3]. As already described in my article Blood Pressure On-The-Go – Monitor From your Wrist Anytime, Anywhere, high blood pressure can lead to serious secondary diseases such as heart attacks, strokes and kidney failure if left untreated. Therefore, regular monitoring is particularly important.

Monitoring Blood Pressure with the Smartwatch

Traditional blood pressure measurement is carried out using an inflatable cuff on the upper arm or wrist. The HUAWEI WATCH D2 measures blood pressure via a pressure cuff in the wristband and is currently the only smartwatch that can perform ambulatory blood pressure measurement (ABPM). It’s is quite an innovation, as this function enables continuous measurements at 15, 20, 30, 45 or 60-minute intervals over 24 hours, including day and night. This means that you can now even measure your blood pressure while sleeping or exercising. For my patients, this offers a new freedom: Instead of carrying the bulky devices around with them or waiting for a doctor's appointment, they can now measure their blood pressure regularly much more easily. You can also set whether the watch measures blood pressure automatically or not.

The HUAWEI WATCH D2 is characterised by a high measurement accuracy comparable to traditional devices and the ability to provide a comprehensive 24-hour blood pressure curve that can detect variations. Nevertheless, you should not jump to conclusions, but discuss the results with a doctor. It is therefore extremely helpful to export the collected data and bring it with you to a doctor's appointment for analysis.

Application Tips:

To effectively integrate cardiovascular monitoring into everyday life, it is advisable to establish monitoring as part of the daily routine, e.g. by wearing a smartwatch during the day and analysing the data via apps. Thanks to functions such as the TruSense™ System monitoring, the watch sends reminders for blood pressure measurements in the morning and supports scheduled measurements so that the user is informed of high blood pressure values in good time. Automatic measurement reminders are available if an abnormal heart rate is detected to recognise potential cardiovascular complications at an early stage.

Important: Self-monitoring is NOT a substitute for professional medical advice. A doctor should be consulted in the event of uncertainties or repeated unusual measurement results.

Good to know - Monitoring is particularly worthwhile for these target groups

- People with risk factors: These include, for example, age, active or former nicotine consumption, elevated cholesterol levels, diabetes mellitus, obesity, family members with early cardiovascular disease (men <55 years, women<65 years), family members with early-onset hypertension or kidney disease should be examined more intensively for the presence of blood pressure abnormalities.

- People aged 75 and over (or 65 and over with risk factors) should carry out ECG measurements for possible signs of atrial fibrillation, to be then evaluated by a health professional.

- People with pre-existing conditions can self- monitor and identify further changes in their ECG, SpO2 and blood pressure readings in the long-term.



- Athletes: Monitoring the heart rate and oxygen saturation or maximum oxygen uptake can be used to optimise training.

Conclusion:

Smartwatches like the HUAWEI WATCH D2 Offer a Holistic Approach to Cardiovascular Health

The combination of ECG, SpO2 and blood pressure measurements enables comprehensive monitoring of cardiovascular health. Together, this data can provide a detailed picture of cardiovascular health and help to recognise potential problems at an early stage.

Continuous monitoring is particularly advantageous because:

• certain diseases can develop without noticeable symptoms and can therefore be treated earlier.
• diseases that have already been diagnosed and treated can change. For example, patients with high blood pressure can have their medication adjusted depending on their blood pressure levels.
• changes in the ECG, oxygen saturation and blood pressure influence each other to some extent, so that recording all parameters can be advantageous.


As a doctor, I see the benefits of such technologies directly in my practice: when patients bring their continuously collected health data to a consultation, this enables treatment to be adapted even more precisely. Changes in ECG values, oxygen saturation or blood pressure can be discussed directly and incorporated into my treatment decisions. This type of data provides valuable information that goes beyond selective measurements and thus enables health professionals to individualise and better tailor treatment.

Medical disclaimer:
The HUAWEI WATCH D2 and the ECG feature is intended to be used by people aged 18 years and over, but is not intended to replace any medical diagnosis or treatment. Data obtained during the use of this device and feature is for personal reference only. Before using the device, please carefully read the Quick Start Guide, Wearing Guide, and Instruction for Use.

Due to national restrictions on obtaining approval / registration as a medical device, the HUAWEI WATCH D2 will only be available in selected European markets, and the ECG feature only works on watches and smartphones purchased in countries where the service is available

- Supported smartphones: Mobile phones with Android 6.0 or compatibles, HarmonyOS 2.0 or compatibles, or iOS 12.0 or compatibles. The Huawei Health app version on your mobile phone must be 11.0 or compatibles. Please make sure that your wearable device and phone are running the latest versions before using ECG.

-Heart rate, blood pressure, SpO2, stress, arterial stiffness, ECG, and skin temperature are not medical device features, monitoring data and results are for reference only and should not be used as a basis for medical diagnosis or treatment.

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