Can Bradycardia Affect The Accuracy Of Pulse Oximetry Spo2%?

Can Bradycardia Affect The Accuracy Of Pulse Oximetry Spo2%?

The human heart is responsible for circulating oxygen-rich blood throughout our bodies, allowing our vital organs to function as required. When heart conditions such as bradycardia occur, the heart does not perform this process as effectively as it needs to. A disruption in the heart's signals can cause a number of health complications that need to be approached differently when being treated.  

What Is Pulse Oximetry 

Pulse oximetry is a procedure used to determine a person's SpO2 or blood oxygen levels. With the use of pulse oximeters like the LOOKEE® A310 Premium Fingertip Pulse Oximeter, healthcare professionals are able to measure the amount of oxygen contained in the blood, also known as oxygen saturation. By making use of probes with light-emitting diodes (LEDs), pulse oximeters shine a red light through the finger's tissue. During this process, sensors on the opposite end of the probe interpret this light and measure what changes occur in the light absorption in oxygenated or deoxygenated blood. After this is done, the device can determine how much of the blood's hemoglobin is saturated with oxygen.

Blood oxygen monitors display SpO2 readings as a percentage. If a person's red blood cells contained 97% oxygenated and 3% deoxygenated hemoglobin, their SpO2 would be 97%. Research done by The American Thoracic Society shows that healthy SpO2 levels are between 95 to 100 percent. Concerns should arise when SpO2 levels start to decrease below 89 percent, as this could be signs of a possible health condition.

When the LOOKEE® Fingertip Pulse Oximeters detect abnormal blood-oxygen levels, an alarm will go off to show that medical attention may be required. Many of the devices come with a built-in plethysmograph to ensure accurate readings that can be taken in an instant. With the use of these portable SpO2 pulse monitors, individuals who suffer from conditions such as sleep apnea and asthma attacks can easily keep track of their vitals.

How Are Heart Conditions Like Bradycardia Monitored? 

When an individual is diagnosed with heart arrhythmia, it means that they are experiencing disruptions in the heart's rhythm, resulting in irregular or abnormal heartbeats. Bradycardia is a form of heart arrhythmia where the heart beats slower than usual. The condition is characterized by a patient having less than 60 heartbeats per minute. Bradycardia can become a life-threatening heart condition. When the heart cannot circulate enough oxygen-rich blood throughout the body, there is a reduced blood flow to the brain and other vital organs. Hence, the condition can indirectly cause a number of severe health complications, including syncope, shortness of breath, and congestive heart failure.

In order to diagnose bradycardia, an ECG test may need to be done. An electrocardiogram, also referred to as ECG or EKG, is performed by a physician or cardiologist to examine the heart's electrical activity and rhythm. These tests are used to monitor and identify various forms of cardiovascular disease. During an ECG, a patient will be required to lay down. Patches known as electrodes are placed onto the body and attached to a machine via ECG leads. It will then display the current resting heart rate to be interpreted by a specialist. 

An ECG can also be performed at home using portable blood-oxygen monitors like the LOOKEE® Personal ECG / EKG Heart Monitor. With the use of medical-grade sensors, it can monitor irregular heartbeats that occur as a result of arrhythmia, atrial fibrillation (AFib), premature ventricular contraction (PVC), bradycardia & tachycardia. Older adults can now easily track their cardiovascular health from the comfort of their homes with the LOOKEE® portable ECG monitor. 

Can Bradycardia Alter Pulse Oximetry Readings? 

A study published by the National Library of Medicine focused on the tendency of changes in blood oxygen saturation and arrhythmia. The study aimed to understand whether there was a correlation between arrhythmia and hypoxemia (i.e., low blood oxygen). The study was conducted in patients who have and have not had a previous history of heart disease. Each group had their SpO2 levels and heart activity monitored simultaneously, and the study found that hypoxemia is an independent risk factor that can result in heart arrhythmia.

Since low SpO2 levels can indirectly lead to irregular heartbeats, the question arises of whether it's possible for irregular heartbeats to alter SpO2 levels. Research has shown that, similarly to the study mentioned above, it is possible. A factor known to affect pulse oximetry readings is poor blood flow circulation. In another study looking at the influence of changes in blood flow on the accuracy of pulse oximetry in humans, two groups of men had their SpO2 levels measured during varying blood flows. The results showed that a low blood flow altered the red light transmitted from the oximeter and thus resulted in a lower SpO2 reading.

Since bradycardia causes the heart to beat slower than it should, it, in turn, slows down blood circulation within the body. Hence, it can be said that bradycardia can affect the accuracy of pulse oximeters, and a healthcare professional should be consulted to correctly monitor blood-oxygen levels while taking the heart disease into consideration. 

Preventing Bradycardia At Home:

Treating heart conditions like bradycardia is not a straightforward process as it can occur due to age, heart complications, or type of medication being used. However, doctors suggest preventing the disease altogether. This can be done by maintaining a healthy heart and making the following lifestyle changes:

Regular heart monitoring: Portable ECG monitors like the LOOKEE® Personal ECG allow older adults to keep track of their heart's rhythm and activity on the go. It is also able to detect heart arrhythmias such as bradycardia and tachycardia.

Stop smoking. Smoking damages the artery walls increasing the chances of developing heart disease, stroke, and cancer.

Follow a healthy diet: This includes limiting the consumption of trans and saturated fats as well as alcohol.

Maintain a healthy weight: Being physically active and staying at a healthy weight is one of the best ways to look after the heart.

Keep pre-existing health conditions under control: Ensure that the correct medication is taken in the right quantities. Conditions such as high blood pressure and diabetes can cause further heart complications when not managed.

Reference List:

NCBI - Pulse Oximetry:

What is Bradycardia?

Is a Slow Heart Rate Good or Bad for You?

The tendency of changes in blood oxygen saturation and arrhythmia: a clinical report of 500 cases:

The influence of changes in blood flow on the accuracy of pulse oximetry in humans:

FDA Warns of Potential Pulse Oximeter Inaccuracies:,accurate%20readings%20from%20some%20oximeters.