Pulse Pressure (Pulse Amplitude, Blood Pressure Amplitude)

Little known yet significant: the pulse pressure. In this article, you will learn more about the role of pulse pressure in health, how to determine your pulse pressure, as well as insights from science and research.

• What is pulse pressure?
• Current findings
• Interpreting pulse pressure
• Causes of high pulse pressure
• Causes of low pulse pressure
• Conclusion

Pulse pressure is the difference between systolic and diastolic blood pressure and is a measure of the elasticity of the large blood vessels. If the vessels are less elastic, blood flows through the body at higher pressure, and pulse pressure increases. This means: the higher the pulse pressure, the higher the resistance of the large vessels. 

To balance the pressure fluctuations between systole and diastole, especially the heart-adjacent arteries have a high proportion of elastic fibers. This elasticity is necessary to create a continuous blood flow from a pulsating stream. For this reason, the aorta and the common carotid artery (Arteria carotis communis) are referred to as Arteria elastotypica that is, arteries of the elastic type.

As a reminder: Arteries are the vessels that carry oxygen-rich blood from the heart into the systemic circulation. Veins return oxygen-poor blood back to the heart.

The pronounced elasticity of the aorta is referred to as the windkessel function of the aorta. The comparison to a windkessel originally comes from hydraulics: a windkessel is usually an air-filled container that balances pressure fluctuations in liquid lines. It is used in devices with pumps or compressors to ensure a constant flow. When a compressor pushes liquid into a system, the pressure in the windkessel rises, and the contained air is compressed. When the pressure drops, the air in the windkessel expands and pushes the remaining liquid.

The aorta follows this principle, except that in this case, elastic vessel walls balance the pressure wave instead of compressed gases like air.

A windkessel is used to extend the lifespan of the pump or compressor, as it does not have to deliver maximum performance constantly. Just as the windkessel protects the compressor from strain, the windkessel function of the aorta protects the heart. If the windkessel function of the aorta declines, for example due to calcifications, the heart has to exert more force, and the pressure in the vessels rises due to a lack of elasticity systolic blood pressure and pulse pressure increase.

To calculate pulse pressure, the diastolic blood pressure is subtracted from the systolic blood pressure:

The calculation of pulse pressure can be illustrated with a simple example:

Systolic Blood Pressure: 120 mmHg

Diastolic Blood Pressure: 80 mmHg

Pulse pressure is expressed in millimeters of mercury (mmHg), just like blood pressure.

While blood pressure plays a fundamental role in medicine, pulse pressure has only received more attention in the last two decades. A particular correlation seems to exist between elevated pulse pressure and the risk of cardiovascular events. Cardiovascular events can affect all parts of the heart and blood vessels. Examples include arrhythmias, heart attacks, or strokes.

Some scientific studies have already uncovered more about the relevance of pulse pressure:

Previous scientific studies suggest that pulse pressure may be a more reliable predictor of cardiovascular events in middle-aged or older individuals than the blood pressure values of systole and diastole.

In cases of hypertension: An investigation that summarized three scientific studies involving over 7,900 individuals concluded that a pulse pressure 10 mmHg higher in individuals with hypertension could predict the likelihood of complications in the cardiovascular system. A correlation with mortality was also observed. However, it is unclear whether these results also apply to younger individuals.

Without cardiovascular preconditions: A study that examined 1,924 women and men without cardiovascular diseases or blood pressure medications over an average of 14 years showed similar results: pulse pressure was (slightly) more indicative for predicting coronary heart disease (CHD) than systolic and diastolic blood pressure. It was observed that the risk of CHD increased with rising pulse pressure while maintaining a constant systolic blood pressure, compared to rising systolic blood pressure with constant pulse pressure. This could mean that individuals with solely elevated systolic blood pressure (isolated systolic hypertension) may have a higher risk of CHD than those with elevated systolic and diastolic values. This correlation is still being discussed in research, as these results were not observed in heart failure (heart insufficiency) both isolated systolic hypertension and hypertension with high systolic and diastolic values led to similar frequencies of heart failure (25% and 22%).

Atrial fibrillation is the most common chronic heart rhythm disorder in adults and increases the risk of death and stroke. Since, among other risk factors, elevated systolic blood pressure also increases the risk of atrial fibrillation, the question arose whether pulse pressure could also be related. Consequently, a study examined 5,331 women and men over a period of 20 years and demonstrated that higher pulse pressure was an important predictor for future atrial fibrillation. The study recommends considering pulse pressure when interpreting blood pressure to include the risk of atrial fibrillation.

When there is a disturbance of blood flow (ischemic) or bleeding (hemorrhagic) in the brain, health professionals refer to it as a stroke. Hypertension and heart diseases are two of many risk factors that increase the risk of stroke. A study showed that elevated pulse pressure could be a factor influencing stroke risk. However, pulse pressure could not determine the risk of death; for this, systolic blood pressure was more indicative.

With the help of BloodPressureDB, you have the opportunity to monitor your pulse pressure. Here, not only systolic and diastolic blood pressure are displayed, but also pulse and pulse pressure in a graphical representation. This allows you to observe the development of pulse pressure over time.

This may sound complicated, but it can be easily explained with the following example:

In this image, you see a representation of normal blood pressure and pulse pressure values as they appear in the app.

For comparison: Blood pressure values from 140/90 mmHg are considered hypertension.

The green and red lines represent systolic and diastolic blood pressure. The pulse is shown in blue, and pulse pressure in yellow.

In this example, the blood pressure on May 1, 2021, is 129/87 mmHg. This corresponds to a normal value and results in a pulse pressure of 42 mmHg (129 – 87 mmHg = 42 mmHg). Over time, small fluctuations in blood pressure can be observed, but the fluctuations in pulse pressure are less pronounced, as seen in the yellow line. By the end of the recording on October 13, 2023, the pulse pressure is about 43 mmHg. The yellow line shows a minimal increase in pulse pressure over time.

Currently, there are no official values for abnormal pulse pressure. In healthy individuals, it is usually below 50 mmHg.

If you are unsure about pulse pressure values or if they are increasing, consult your doctor for advice. The more accurately and frequently you document blood pressure and pulse pressure values, the better they can be interpreted.

Pulse pressure is displayed by many automatic blood pressure measuring devices. If a device does not display pulse pressure or if it is measured manually, pulse pressure can be calculated by subtracting the diastolic value from the systolic value.

The result: The gap between systolic and diastolic values widens, and pulse pressure increases. Individuals with large amounts of muscle mass can also have elevated pulse pressure.

In general, an active lifestyle promotes health. Whether elevated pulse pressure in very athletic individuals affects health remains unclear to this day.

During the natural aging process of humans, the large arterial blood vessels become stiffer. This is due to remodeling in the vessel walls over time: elastic fibers (elastin) decrease, while rigid collagen I and calcifications increase. The result: the left ventricle pumps blood through "stiffer" vessels into the systemic circulation and must pump against a higher vascular resistance than with elastic vessels pulse pressure increases.

Due to the increased effort, the left ventricle enlarges over time, which health professionals refer to as hypertrophy. The higher pulse pressure in the small vessels of organs, such as in the brain or kidneys, can lead to tissue damage.

Typically, systolic blood pressure increases with age, while diastolic blood pressure decreases.

If only the systolic blood pressure rises above 140 mmHg, health professionals refer to it as isolated systolic hypertension. Isolated systolic hypertension is the most common form (75%) of hypertension in previously untreated individuals over 75 years old. Younger individuals can also have isolated systolic hypertension, although a simultaneous increase in systolic and diastolic values is more common. This form of hypertension is associated with an increased risk of severe cardiovascular disease and should be persistently treated.

Herbert has a regular blood pressure of 150/95 mmHg. These values are considered too high according to medical guidelines and are referred to as hypertension.

Manfred has a regular blood pressure of 150/80 mmHg. In Manfred's case, only the systolic value (150 mmHg) is elevated, while the diastolic value (80 mmHg) is within the normal range this is referred to as isolated systolic hypertension.

Should Herbert and Manfred visit their general practitioner due to their blood pressure values?

Yes, both Herbert and Manfred should have their blood pressure values evaluated by a doctor, as most professional societies recommend treatment for elevated systolic values as well as for elevated systolic and diastolic values.

An increased or widened pulse pressure can be triggered by various diseases. Here are some examples:

• Aortic valve insufficiency
• Aortic sclerosis: increased vascular resistance
• Severe iron deficiency: blood viscosity changes
• Atherosclerosis
• Overactive thyroid (hyperthyroidism): elevated systolic blood pressure

Low or narrow pulse pressure can occur in the following diseases:

Women tend to have less elevated pulse pressure in young adulthood than men. However, at an older age, women's pulse pressure increases more rapidly and steeply than that of the other sex. A study comparing 22 studies has shown that this difference also exists in non-industrialized countries. This suggests that the results are primarily due to the human aging process rather than a specific lifestyle.

This suggests that special attention should be paid to cardiovascular health in older women.

Studies have shown that elevated pulse pressure could primarily predict events of the cardiovascular system. Middle-aged and older individuals could particularly benefit from regular monitoring of pulse pressure.

Isolated systolic hypertension is the most common form of high blood pressure in older individuals. With increasing systole but constant or decreasing diastole, pulse pressure rises. These results could mean that isolated systolic hypertension is associated with a higher risk of cardiovascular events than hypertension where both systole and diastole are elevated. Future studies could clarify this issue.

It is still unclear whether these results are relevant for younger people and whether the observed relationships between pulse pressure and cardiovascular diseases are coincidental or have a real influence on each other.

However, pulse pressure should not be normal simply because the diastolic blood pressure value is too high. A too high diastolic blood pressure increases the risk of developing coronary heart disease, regardless of whether only the diastolic blood pressure is elevated or whether the systolic blood pressure is also too high. Therefore, a normal pulse pressure is always based on normal diastolic blood pressure values and never on elevated diastolic blood pressure.

Our tip: Document your blood pressure with the BloodPressureDB app. This way, you will always have your pulse pressure in view.

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