Heart Health and Pulse Pressure

When a nurse or doctor straps a blood pressure cuff around your arm, pumps it up to give your bicep a good squeeze and then watches where the needle lands on the dial, the two numbers that result are your systolic and diastolic blood pressure readings. They're taken at opposite ends of the cardiac cycle and represent the highest and lowest blood pressure levels at that particular time.

You may learn that your blood pressure is, say, 120/80, which is read as "120 over 80." The first number represents what's called systolic pressure, which indicates how much pressure your blood exerts against the walls of your arteries when your heart beats, according to the ​American Heart Association (AHA). Your diastolic pressure, the second number, represents how much pressure is exerted between beats when the heart is at rest. (Incidentally, blood pressure is measured in units of mm Hg, which stands for millimeters of mercury.) A reading of 120/80, by the way, is considered healthy and normal by the AHA.

There's another measurement of heart health, however, that you may not be familiar with: pulse pressure. Pulse pressure is calculated by taking the difference between systolic blood pressure and diastolic pressure. The pulse pressure reading for a person whose blood pressure is 120/80, therefore, would be 40.

There's some evidence that pulse pressure is a better predictor of a person's heart health than systolic or diastolic blood pressure alone. However, using pulse pressure to diagnose cardiac problems is complicated. Because it's determined using systolic and diastolic readings it really doesn’t provide unique information. In other words, saying that someone has an “elevated pulse pressure” is usually the same as saying that they have an “elevated systolic blood pressure,” which will already have been determined.

What's more, a person with a normal blood pressure reading of 120/80 will have a pulse pressure of 40. But a person with a pulse pressure of 40 won't necessarily have normal blood pressure. For instance, someone whose blood pressure reading is 140/100 also has a pulse pressure of 40 (the difference between 140 and 100 is 40), but that person's blood pressure would be considered elevated.

Sometimes pulse pressure does provide important information. There's research showing that pulse pressure can be valuable when looking at a patient’s overall risk profile. Several studies have identified that high pulse pressure:

• Causes more artery damage compared to high blood pressure with normal pulse pressure
• Indicates elevated stress on a part of the heart called the left ventricle
• Is affected differently by different high blood pressure medicines

So if you're diagnosed with high blood pressure, your doctor may consider it when designing your overall treatment plan.