Generality
The systolic pressure, or maximum pressure, is the value of arterial pressure when the heart is contracting, in order to push the blood into circulation; in other words, it is blood pressure with each heartbeat.
Brief review of what blood pressure is
Arterial pressure is the force that blood exerts against the walls of blood vessels, following the pump action carried out by the heart.
Measured in millimeters of mercury ( mmHg ) and in a state of rest, blood pressure is usually defined by the values of systolic pressure and diastolic pressure .
In humans, blood pressure depends on factors, such as:
- Force of contraction of the heart;
- Systolic range (ie the amount of blood leaving the heart at each ventricular contraction);
- Heart rate (ie the number of heartbeats per minute);
- Peripheral resistances (ie resistances opposed to blood circulation from the state of constriction of small arterial vessels);
- Elasticity of the aorta and large arteries (vascular compliance);
- Volemia (ie the total volume of blood circulating in the body).
What is systolic pressure?
The systolic pressure - also called maximum pressure or simply " maximum " - is the value of arterial pressure when an individual's heart contracts. In other words, it is the value assumed by arterial pressure with each heartbeat necessary to send blood into circulation (to understand the mechanism by which the heart works, see the cardiac mechanical article).
The systolic pressure is in contrast to the diastolic pressure, which represents, instead, the value of arterial pressure when an individual's heart relaxes, therefore the pressure value straddling two heartbeats.
Where does the term "systolic" come from?
The term "systolic" derives from the word " systole ". In the medical field, the word "systole" indicates the phase of contraction of the heart, due to the accuracy of the myocardium.
During systole, blood is seen passing from the cardiac to the cardiac ventricles and from the cardiac ventricles to the blood vessels.
How is arterial blood pressure reported?
Already mentioned in the unit of measurement used, in reporting the arterial pressure of a person, doctors compare the systolic pressure with the diastolic pressure. From this it follows that, in the report, the upper value is the maximum pressure, while the lower value is the minimum pressure.
Now, if in an individual the systolic pressure is equal to 120 mmHg and the diastolic pressure is 80 mmHg, the pressure ratio (so the total arterial pressure) of the subject in question will be written 120/80 mmHg and read "120 out of 80 millimeters of mercury ”.
Normal systolic pressure
The measurement of arterial pressure in an individual in excellent health can present systolic pressure values between 90 and 120 mmHg, and diastolic pressure values between 60 and 80 mmHg.
Therefore, the so-called normal systolic pressure falls within a range of values not lower than 90 mmHg and not higher than 120 mmHg.
Associated pathologies
Almost always in association with diastolic pressure, the systolic pressure can be permanently subjected to drops or increases that border the limits of normality. These alterations generally represent something that does not work perfectly in the human body.
Going into more detail:
- When the systolic pressure is constantly lower than 90 mmHg and the diastolic pressure is constantly lower than 60 mmHg (so the maximum / minimum ratio is <90/60 mmHg), the doctors talking about hypotension or low blood pressure.
- When the systolic pressure is constantly higher than 120 mmHg but less than 140 mmHg and when the diastolic pressure is constantly higher than 80 mmHg but less than 90 mmHg (so the maximum / minimum ratio is between 120/80 and 139/89 mmHg), doctors talk about pre-hypertension.
- Finally, when the systolic pressure is constantly higher than 140 mmHg and the diastolic pressure is constantly higher than 90 mmHg (so the maximum / minimum ratio is> 140/90 mmHg), the doctors talk about hypertension or high blood pressure.
As readers can see, in order to assess the arterial pressure of an individual and any anomalies, it is necessary to consider, to obtain a complete picture of the situation, both the maximum pressure and the minimum pressure.
Hypotension or low blood pressure
The state of hypotension can have a different origin; in fact, it can be:
- A physiological condition due to genetic factors or to the regular practice of physical activity ( constitutional hypotension ). In these circumstances, the drop in blood pressure is slight both in the systolic values and in the diastolic values and lacks real symptomatology.
Generally, constitutional hypotension is not a dangerous condition; indeed, according to some experts, it would seem to protect against cardiovascular risk.
- A condition due to a particular disease ( pathological hypotension ). In such situations, the degree of maximum low pressure and low minimum pressure can be extremely marked and, therefore, cause symptoms and complications.
Pathological hypotension requires ad hoc treatment.
Among the diseases that can cause a substantial reduction in blood pressure, include: Addison's disease, anemia due to folate deficiency or vitamin B12, anaphylactic shock, dehydration, myocardial infarction, congestive heart failure, some forms of arrhythmia, bradycardia, valvulopathies, pulmonary embolism, septic shock, acidosis, severe traumatic brain injury and spinal cord injuries.
- A condition due to taking certain drugs ( drug hypotension or iatrogenic hypotension ). In these situations, the drop in systolic pressure and diastolic pressure is variable, in the sense that it can be more or less marked.
Among the drugs that can potentially cause hypotension, include: antihypertensive drugs (diuretics, calcium channel blockers, angiotensin II receptor antagonists, alpha-blockers, beta-blockers, etc.), trinitrina (or nitroglycerin), the anesthetics used for spinal anesthesia, narcotics, tricyclic antidepressants, levodopa combined with carbidopa and some drugs for erectile dysfunction (eg: Viagra, Levitra or Cialis) in association with nitroglierin.
- A condition due to pregnancy, to be precise to the hormonal changes that gestation involves for the woman ( gestational hypotension ).
Normally, in the first 24 weeks of pregnancy, pregnant women are subject to an average drop in systolic blood pressure of around 5-10 mmHg and an average decrease in diastolic blood pressure greater than 10 mmHg.
To learn more, readers can consult the article: Low Pressure in Pregnancy.
Pre-hypertension
Pre-hypertension is not exactly a pathological state - as it is hypertension or intermediate / severe degree hypotension - but it is rather a condition to be monitored, as if it were a sort of alarm bell that warns of the presence of something abnormal.
Those suffering from hypertension do not need a pharmacological cure, but must change their lifestyle (which is often wrong) and pay attention to:
- Supply;
- Stress;
- Smoke;
- Alcohol;
- Physical activity.
If timely, the adoption of a healthy lifestyle allows the control of pre-hypertension and the normal values of systolic and diastolic pressure.
Hypertension or high blood pressure
Hypertension is a clinically relevant condition that, if not treated properly and timely, can lead to serious complications, sometimes even with a fatal outcome.
In fact, high levels of systolic pressure and diastolic pressure cause the arterial blood to flow in such a way as to produce microlesions in the arteries in which it circulates, which, precisely for this reason, slowly undergo a process of atherosclerosis ( that is, they undergo hardening and are the site of atheromas).
Atherosclerosis increases the risk of thromboembolism and affects the circulation of important organs, such as the brain, heart, kidneys and eyes.
Curiosity
High blood pressure in the elderly behaves differently than in adults under 60 years. In fact, while in the latter (adults under 60), there is a marked increase in both the minimum and maximum, in the first (elderly) there is a significant increase in systolic pressure and a decidedly more limited increase in diastolic pressure.
