Blood pressure and pulse
The body's blood pressure control is governed by complex mechanisms that are still not fully understood. However, the main factors that lead to high blood pressure are known today. It is clear that there isnt a single reason why blood pressure becomes too high. The causes of the most common form of high blood pressure, essential hypertension, are found both in genetics and in lifestyle factors such as unhealthy diet, lack of exercise, overweight, and also chronic stress. Part of these regulatory mechanisms is influenced by hemodynamic factors (pressure within the blood vessels). The pulse describes the number and strength of the heart's beats that can be felt in the arteries and is given per minute. It plays a key role in the pressure inside the blood vessels. Heart rate and pulse rate can differ, however, if not every beat is strong enough to create a detectable pressure wave in the arteries.
Hemodynamic factors in blood pressure control
The three main hemodynamic factors that control blood pressure are heart rate (or pulse rate), stroke volume, and peripheral resistance. A normal heart rate is between 60 and 80 beats per minute. Stroke volume is the amount of blood the heart pumps out with each beat. On average that's 70 milliliters, or 0.07 liters. Cardiac output is the product of stroke volume and heart rate. That means that with a heart rate of 60 beats per minute, the heart pumps more than four liters of blood per minuteroughly the total blood volume of the body (about five liters on average).
Blood pressure (BP) is the product of cardiac output and peripheral resistance. Put simply, the formula looks like this: BP = HR x SV x PR (HR = heart rate; SV = stroke volume; PR = peripheral resistance). This formula helps explain how changes in one measure affect the others. One observed effect, for example, is the sudden increase in heart rate after giving certain blood-pressure-lowering drugs that reduce peripheral resistance by widening blood vessels (so-called alpha-blockers). Lowering peripheral resistance will, according to the formula, lower blood pressure. The body then compensates by increasing heart rate and, to a limited extent, stroke volume. This explains why (compensatory) tachycardia (fast heartbeat) is listed as one of the most common side effects for alpha-blockers in package leaflets.
Before taking:
After taking:
Athletes have well-trained heart muscles that produce a larger stroke volume. Instead of the average 70 milliliters, these hearts pump 100 milliliters or more per beat. Since the body needs to circulate about four to five liters of blood at rest to supply all organs adequately, athletes have a low resting pulse ratebecause with a stroke volume of 100 milliliters the heart only needs to beat about 45 to 50 times per minute to reach the required four to five liters per minute (cardiac output). The benefit of a lower pulse rate is a noticeably longer diastole, meaning more filling time for the heart chambers and for the coronary arteries that supply the heart.
Sources:
- https://www.kup.at/kup/pdf/12347.pdf
- https://www.internisten-im-netz.de/fachgebiete/herz-kreislauf/begriffe-rund-ums-herz.html
- http://physiologie.cc/VII.1.htm
- https://www.thieme-connect.de/products/ebooks/lookinside/10.1055/b-0034-5311
- https://www.msdmanuals.com/de-de/heim/herz-und-gefäßkrankheiten/sport-und-das-herz/das-sportlerherz
This article comes from BloodPressureDB – the leading app since 2011 that helps hundreds of thousands of people monitor their blood pressure every day.
Our content is based on carefully researched, evidence-based information and is continuously updated (as of 11/2024).
Author Sabine Croci is a certified medical assistant with many years of experience in internal medicine and cardiology practices as well as in outpatient care. Since 2015 she has led the editorial team at BloodPressureDB. With additional qualifications as a paramedic, first responder, and training in various therapy and emergency areas, she provides well-founded, practical, and reliably reviewed information.
Author Sabine Croci is a certified medical assistant with many years of experience in internal medicine and cardiology practices as well as in outpatient care. Since 2015 she has led the editorial team at BloodPressureDB. With additional qualifications as a paramedic, first responder, and training in various therapy and emergency areas, she provides well-founded, practical, and reliably reviewed information.
