What is Pulse Wave Velocity?
Each time your heart beats it induces a wave along the aorta and arterial tree.
This wave leads to blood volume changes in the vessels that expand and contract in response to these changes.
Pulse Wave Velocity is the propagation speed of this wave along the arteries. Increased stiffness of the arteries increases Pulse Wave Velocity. It is the best way to assess cardiovascular health.
Heart rate is the frequency that the heart beats, and is an indicator of physical fitness. The more active you are, the lower your heart rate is.
Blood pressure measures the pressure of blood on the arterial wall. It is one of the major cardiovascular risk factors, and can lead to an increased risk of stroke, heart failure, and kidney failure.
While heart rate and blood pressure measurements are useful in evaluating cardiovascular health, they do not give a complete picture of health. Pulse Wave Velocity, on the other hand, is an accurate stand-alone measurement of heart health.
What does the Pulse Wave Velocity say about my health?
Measuring Pulse Wave Velocity is recognized by the medical community as the best way to assess cardiovascular health, because it takes both arterial health and blood pressure variations into account.
“Decreasing PWV shows cardiovascular state improvement.” Professor Pierre Boutouyrie, European Society of Hypertension
“Elevated PWV is jointly associated with future systolic blood pressure and incident hypertention.” Dr. Gary Mitchell, Framingham Heat Study
Diseases such as diabetes, cholesterol or high blood pressure induce stiff arteries, which lead to an elevated Pulse Wave Velocity.
An elevated Pulse Wave Velocity is a sign of poor heart health, indicating a risk of having or developing high blood pressure. On the other hand, the more flexible the artery, the better your heart health.
What are the pathologic risks associated with high Pulse Wave Velocity?
Medical research has demonstrated a strong correlation between the stiffness of the arteries and the risk of a cardiovascular incident. Stiffer arteries indicate a greater risk for high blood pressure, stroke or heart attack.
Pulse Wave Velocity has been proven to be as reliable as the Framingham risk score, which is currently the most common way of predicting one’s risk of cardiovascular incident. Unlike the Framingham risk score, Pulse Wave Velocity is a direct measurement of your cardiovascular health.
Can I improve my Pulse Wave Velocity?
The good news is that you can decrease your Pulse Wave Velocity with healthy lifestyle changes. If you are overweight or obese, losing weight can have a tremendous impact. Engaging in physical exercise, and limiting salt and alcohol intake may also help to decrease your Pulse Wave Velocity. Additionally, managing stress can help you avoid elevated heart rate and blood pressure readings that can hurt your arteries over the long term.
Paired with the Withings Body Cardio, the Withings Health Mate® app interprets measurements and trends based on age, and tailors recommendations to improve cardiovascular health accordingly.
How does the Withings Body Cardio measure Pulse Wave Velocity?
The Withings Body Cardio computes Pulse Wave Velocity based on a person’s age and the time it takes for blood to go from the aorta to the vessels in the feet.
Thanks to its sensors, the Withings Body Cardio detects slight weight variations on the scale caused by heartbeats. With this information, the scale can sense the moment when blood is ejected from the aorta and the moment when it reaches blood vessels in the feet. The time between these two events is then compared to the user’s height, and the Withings Body Cardio can compute the Pulse Wave Velocity in approximately 15 seconds.
Note that after installing your Withings Body Cardio, you will need five valid measurements before you can access the Pulse Wave Velocity graph. These measurements are required to calibrate Pulse Wave Velocity measurement on your scale. You will receive a Timeline item every time you get a valid measurement, and a final one once you can access the graph.
Why do my Pulse Wave Velocity measurements vary throughout the day?
Various factors can lead to variations in blood pressure and Pulse Wave Velocity:
- coffee consumption
- stress level
- physical activity level
- time of day
- alcohol intake
The best way to assess your cardiovascular health is to measure your Pulse Wave Velocity over time.
Getting a reliable measurement
Follow these tips to improve the reliability of your measurement:
- Measure your Pulse Wave Velocity in a quiet room with stable temperature (ideally 71.6-73.4°F / 22-23°C).
- Measure your Pulse Wave Velocity at the same hour every day, and at least three hours after a meal, drinking coffee or smoking a cigarette.
- Try to take the measurement without moving or speaking.
How reliable are the Withings Body Cardio measurements compared to gold standard medical devices?
To assess the validity of the measurement of the Withings Body Cardio, Withings has performed a study following the recommended guidelines, which compared the measurement of the Aortic Pulse Wave Velocity by the Withings Body Cardio to a Sphygmometer, which is generally accepted as the most simple, non-invasive, robust, and reproducible method to determine arterial stiffness.
The preliminary study was conducted on a group of more than 100 individuals in a clinical setting by a medical team specializing in arterial stiffness (Professor Pierre Boutouyrie, European Hospital Georges Pompidou, Paris, France). The results of this study demonstrates that Pulse Wave Velocity measurements taken with the Withings Body Cardio yielded similar results to measurements taken using the Sphygmometer. These results will be published at the European Society of Hypertension Congress in Paris in June 2016. Furthermore, a multicentric study is underway to confirm these results.
How is Pulse Wave Velocity currently used in medical procedures?
Despite its medical value in assessing cardiovascular health, Pulse Wave Velocity has been restricted to those already diagnosed with high blood pressure to assess damage that may have occurred because of their condition.
Indeed, the traditional measurement takes at least 20 minutes, uses a specific device called a sphygmometer, and requires a well-trained operator to perform the measurement.
Because of its complexity, Pulse Wave Velocity measurement is not widespread, even in a hospital setting. But now, for the first time, Pulse Wave Velocity can be measured at home via the Withings Body Cardio to assess overall cardiovascular health.