Samsung is on a mission to bring health and well-being to people’s lives. To realize this vision, we are working for a long time in the health area. As a part of it, Samsung introduced Samsung Health monitor application in 2020, which can help users monitor their cardiac health, by tracking Blood Pressure (BP) and Electrocardiogram (ECG). SRBD is also a part of this mission to develop BP & ECG features for Samsung Health Monitor Application.

Blood Pressure Measurement

High blood pressure is commonly linked to brain, kidney and heart diseases, and if left untreated, it can lead to stroke and coronary heart disease. Galaxy smartwatches can measure blood pressure via the Samsung Health Monitor app, which provides users with deeper insight into health and allows them to make more informed decisions about their wellness. Blood Pressure is measured when the heart pumps blood into the large blood vessels of the human circulatory system. Then the blood moves throughout the body that puts pressure on the vessel walls which is said to be the blood pressure level.
https://www.youtube.com/watch?v=f6ho0aa1r3g

The blood pressure measurement or Samsung Health Monitor app cannot diagnose hypertension, or other conditions, or check for signs of a heart attack. It is not meant to replace traditional methods of diagnosis or treatment by a qualified healthcare professional.

Electrocardiogram Monitoring

It is estimated that around 33.5 million people worldwide are affected by Atrial Fibrillation (AFib), a common form of abnormal heart rhythm. AFib is often the cause of heart complications, including blood clots, failure, and stroke.
ECG or Electrocardiogram helps to detect the heartbeat rhythm and electrical activity of the heart. The ECG sensor records time and strength that is taken by an electrical signal to make a heartbeat. Based on these readings, it checks whether a person is having atrial fibrillation or irregular heartbeat rhythm.
https://www.youtube.com/watch?v=G5WzPrhqcOA&t=2

In case of poor recording, data could not be analyzed. This usually happens if there is noise in the ECG recording which may occur due to motion during the recording or if the watch did not have enough skin contact with your wrist or finger.
ECG & Blood Pressure on Galaxy Watch are officially available in the following countries: Austria, UAE, UK, Belgium, Bulgaria, Croatia, Chile, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Indonesia, Ireland, Italy, Latvia, Lithuania, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, South Korea, Spain, Sweden, and Switzerland. Will support more courtiers soon.
Available only with a compatible Galaxy smartphone with Android 7 or above & smartwatch from Galaxy active2, Galaxy watch3, Galaxy watch4 and now the latest Galaxy watch 5 too.

Before a medical device can be legally sold in the U.S., the person or company that wants to sell the device must seek approval from the FDA. To gain approval, they must present evidence that the device is reasonably safe and effective for a particular use.
Samsung has received FDA clearance for smartwatch ECG tracking. This product is classified as "Software as Medical Device" and is approved for use by adults (22 years or older) by US FDA

Some other features are coming soon too.
Please use it after reading the warnings below.

1) The ECG Monitor App is not meant to replace traditional methods of diagnosis or treatment by a qualified healthcare professional. If you think you are having a medical emergency, contact your local emergency services immediately.

2) The ECG Monitor App cannot diagnose cardiac conditions or look for signs of a heart attack.

3) DO NOT change your medications or dosage without first consulting your doctor.

4) ECG rhythm-classification results displayed by the ECG Monitor App are for informational purposes only.

5) DO NOT interpret or take clinical action based on the ECG App measurements without first consulting with a qualified healthcare professional.

6) DO NOT use the ECG Monitor App if you have an implanted pacemaker, implanted cardiac defibrillator, or other implanted electronic devices.

7) DO NOT use the ECG Monitor App if you have known arrhythmia other than Atrial Fibrillation.