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How To Calculate Blood Pressure

How Is An Abnormal Map Treated

Mean Arterial Blood Pressure (MAP), how to calculate it?

An abnormality in the MAP is generally a sign of some underlying problem affecting either the cardiac output or the systemic vascular resistance. This means that the treatment depends on which of these factors is not normal. The ultimate goal is to avoid end organ damage caused either by a MAP that is too low or a MAP that is too high.

A low MAP is dangerous because of underperfusion of the major organs. In order to bring up the pressure, IV fluids or blood transfusions can be given in order to increase the preload to the heart so it has more volume to eject. This will raise the cardiac output, which may increase the MAP. Vasopressors, which are medications that help to constrict the blood flow, can be given to increase the peripheral vascular resistance. In addition, many of these medications increase the heart rate as well, which will also serve to raise the cardiac output.

Treating a MAP that is too high is also important in order to reduce the risk of stroke and secondary heart failure. There are medications, like oral or IV nitroglycerin, which will relax the blood vessels so as to reduce the systemic vascular resistance quickly. The higher the MAP and the longer it is left unchecked, the greater is the chance for heart failure by a heart that cannot exert a force great enough to overcome the high arterial pressures.

Can You Calculate Blood Pressure From Heart Rate

Many people want to know their blood pressure but may be unable to measure it. There are many reasons for this including not owning a BP monitor or having access to one at a particular time. Since a heart rate can be checked anywhere at any time, many people have wondered, can you calculate blood pressure from heart rate?

Blood pressure cannot be calculated from the heart rate. Knowing the heart rate alone cannot determine what the bodys blood pressure reading is. Calculating blood pressure requires a sphygmomanometer, blood pressure machine or monitor.

This article will dive into the blood pressure and heart rate relationship. Ill inform you if blood pressure and heart rate moves up and down together or if one can be high and the other low.

Easy Ways How To Calculate The Map

An understanding of the mean arterial pressure or MAP begins with knowing what the human blood pressure is all about and how it is determined. Most people recognize that blood pressure depends on the forceful contraction of the heart, which beats steadily and in a rhythmic fashion in order to pump blood to all portions of the human body.

There are two basic measurements that are ordinarily done in order to assess this critical function of the heart these are the measurement of the systolic blood pressure and the diastolic blood pressure. From these two measurements, a rough estimate of the mean arterial pressure can be arrived at. Using a simple sphygmomanometer or blood pressure measuring device, an individuals blood pressure can be determined and the mean arterial blood pressure can be calculated from this measurement.

The systolic blood pressure is the pressure generated on the walls of the arteries in the human body as the heart is contracting. This is the upper number when it comes to measuring the blood pressure. The diastolic blood pressure, on the other hand, is the pressure found against the blood vessel walls during the period of time when the heart is in diastole or is relaxed. This is the lower number measured when checking an individuals blood pressure. The normal blood pressure in an adult is about 120/80 mm Hg.

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Is Heart Rate And Blood Pressure Related

Heart rate and blood pressure can both inform us how well the heart is operating and signal cardiac problems 2. A common question asked is heart rate and blood pressure related?

The relationship between the heart rate and blood pressure can vary depending on the situation 3. They can both increase and decrease at the same time. One can increase while the other one decreases. One can decrease while the other one increases.

Lets take a look at four different situations.

  • Blood pressure and heart rate decrease at the same time.
  • Blood pressure and heart rate increase at the same time.
  • Blood pressure increases and the heart rate decreases.
  • Blood pressure decreases and the heart rate increases.
  • Lets take a look at some common questions related to blood pressure and heart rate and when each one may occur 4.

    Can you have high blood pressure and a low heart rate? Blood pressure can be high when the heart rate is low. This can be caused by certain medications, brain injury, internal bleeding or thickened heart tissue. This can cause dizziness, fainting, fatigue or shortness of breath.

    What does it mean when your blood pressure is low and your pulse is high? Blood pressure can be low and pulse high when dehydrated, bleeding or having a severe infection. Having low blood pressure can increase the heart rate to increase blood flow and pressure.

    When Should You Monitor Map


    Mean arterial pressure is considered to be a better indicator of a tissue perfusion than SBP, precisely because it accounts for the difference between the duration of the diastole and systole parts of the cardiac cycle. Hence, it is typically monitored in cases of organs perfusion. Some of these cases include:

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    Tips For Checking Your Own Blood Pressure

    There are certain factors that can cause blood pressure to temporarily rise. For example, blood pressure normally rises as a result of:

    Try to avoid as many of these factors as you can when taking your blood pressure. Also, try to measure your blood pressure at about the same time each day. Your doctor may want you to check your blood pressure several times during the day to see if it fluctuates.

    What If I Dont Have Equipment

    You dont need a blood pressure cuff to take your resting heart rate, which is another measurement that helps indicate heart health. Digital monitors usually display both blood pressure and heart rate, but you can determine the former on your own by checking your pulse by hand. Your pulse is how many times your heart pumps per minute.

    First, locate the artery below the thumb on the inside of your wrist and place two fingers there. Count how many times you feel your heartbeat over a 15-second period, and then multiply your count by four to get your resting heart rate.

    When youre checking pulse by hand, youre looking for more than just a number. Youre also checking for a regular rhythm, which indicates a strong pulse.

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    At Your Local Pharmacy

    Public blood pressure machines, such as those found in pharmacies, may provide helpful information about your blood pressure, but they may also have some limitations. The accuracy of these machines depends upon several factors, such as a correct cuff size and proper use of the machines. Ask your health care provider for advice on using public blood pressure machines.

    How To Calculate The Map

    Calculating systolic, diastolic and MAP from blood pressure traces

    The true calculation of the MAP is the cardiac output multiplied by the systemic vascular resistance added to the central venous pressure. In most cases, the central venous pressure is zero or nearly zero, which makes the MAP most dependent on the cardiac output and the systemic vascular resistance.

    In reality, the most accurate representation of the MAP is determined by placing an invasive central line in a person and determining the actual cardiac output, central venous pressure, and systemic vascular resistance. This, however, is not very practical and, as it turns out, the MAP can be calculated simply by knowing the systolic blood pressure and the diastolic blood pressure. Machines that determine an individuals blood pressure reading will often also show the MAP.

    The equation with which the MAP can be calculated is the this: MAP = DBP + 1/3, where the DBP is the diastolic blood pressure and the SBP is the systolic blood pressure. So for example is the blood pressure is 120/80 mm Hg his MAP would be 93,3. This is how you would calculate it-

    MAP= 93,3 mm Hg

    Another way to do this would be to multiply the diastolic blood pressure by 2 then add the sum to the systolic blood pressure and divide it by 3. It gives you the same answer.

    MAP = SBP + 2 / 3

    MAP = 120 +2 / 3

    MAP = 120 +160 /3

    MAP = 93,3 mm Hg

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    Where Can I Learn How To Take My Blood Pressure Myself

    In Germany and other countries, people with high blood pressure can attend patient education courses that teach a number of things, including how to measure your blood pressure. As part of specialized disease management programs for people who have narrow coronary arteries , statutory health insurers offer additional healthcare services. These include patient education about high blood pressure. Some doctors practices don’t offer these courses, though.

    What Is The Blood Pressure Equation Used For

    The blood pressure equation, including the stroke volume equation and the cardiac output equation, tells the doctor how stable or critical patients are. Your heart, kidneys, brain, nervous system, and hormones all work in unison to keep your blood pressure in a good range. Normal blood pressure is anything 120 or less systolic and 80 or less diastolic. If the blood pressure is too high, this can cause damage to the kidneys or the heart can fail. Low blood pressure can also be serious and any severe fluctuations needs to be addressed and treated as soon as possible.

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    How To Measure Blood Pressure

    There are a few ways to measure blood pressure. In this paragraph, we will cover only non-invasive methods of measuring blood pressure.

    The fastest method to assess blood pressure is by palpation detecting a pulse over patient’s arteries. Although not very accurate, it is especially useful in emergencies: saving victims of car accidents, patients undergoing cardiac arrest, etc. It is assumed that when the systolic blood pressure of a patient is over 70 mmHg, the pulse should be palpable over carotid , femoral and radial arteries. When the systolic blood pressure drops to > 50 mmHg, we can feel the pulse only over carotid and femoral arteries and with a pulse between 40-50 mmHg, just over carotid artery.

    There is a medical phenomenon known as “white coat syndrome” . Many patients fears being examined by a doctor and, during measurement, their blood pressure raises as a response to the stress they are feeling. This causes falsely high results of blood pressure test and can lead to unnecessary treatment. Below the final method of how to measure blood pressure eliminates this problem.

    How To Calculate Blood Pressure

    Blood Pressure Chart / Calculator by Age &  Height

    A device called a sphygmomanometer is used for blood pressure measurement. This usually consists of a stethoscope, pump, dial, and arm brace. Even though nowadays automatic devices with digital displays and sensors are also widely used.

    It would be best to uncross your legs and sit back for blood pressure test. Typically you have to roll up sleeves or take out some long-sleeved clothing to put the band around your upper arm. Try relaxing or avoid talking during the blood pressure test.

    During the test:

    • Take out one of the arms to the position where your heart lies to put a cuff around it. In this position, the arm should be supported, for example, with a chair cushion or arm.
    • To limit the blood flow, the cuff is wrapped. The pinch may feel uncomfortable but lasts just a few seconds.
    • The strain in the cuff is released slowly, and the heartbeat can be listened with a stethoscope. Digital devices use vibration sensors.
    • The blood flow begins to return to your arm at two points, and the pressure is assessed at that time. These values are used to calculate blood pressure. You can find your results immediately either on the test or the digital display by the healthcare provider.

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    How To Take Your Blood Pressure

    You can take your blood pressure at home using a blood pressure monitor and use the blood pressure calculator as guidance on what your reading means. Ensure the monitor has been clinically validated. Find a list of blood pressure monitors available for home use on the British and Irish Hypertension Society website.

    • Sit quietly and comfortably on a chair with legs uncrossed and feet flat on the ground with an even surface in front of you.
    • Place your arm on the surface in front of you so that it is supported level with your heart. Remove tight clothing and wrap the cuff around your upper arm.
    • Activate the blood pressure monitor, the cuff will inflate to restrict the blood flow in your arm is it gauges your blood pressure. This will last for a short time.
    • As the cuff deflates, your reading is displayed on the monitor. Enter the two numbers into the blood pressure checker to determine the health of your reading.

    What Do The Readings Mean

    As a general guide:

    140/90mmHg or over you may have high blood pressureMost doctors use 140/90mmHg as the cut off for point for diagnosing high blood pressure . This is the point where your risk of serious health problems goes up. They might prescribe medications and advise you to make changes to your lifestyle to bring your blood pressure down. 120/80mmHg up to 140/90mmHg pre-high blood pressureAlso called high-normal blood pressure. This is not high blood pressure, but it is a little higher than it should be and means you could go on to develop high blood pressure. See how you can make healthy changes to your lifestyle to lower it. 90/60mmHg up to 120/80mmHg ideal blood pressureAlso called normal blood pressure. Your blood pressure reading is healthy. At this level you have a much lower risk of heart disease and stroke. Following a healthy lifestyle will help you to keep it in the healthy range. 90/60mmHg or lower you may have low blood pressureLow blood pressure usually isnt a problem, but it can sometimes make you feel faint or dizzy or could be a sign of another health problem.

    The video below explains how your blood pressure numbers are linked to the risk of stroke and other disease.

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    Regulation Of Blood Pressure

    The endogenous, homeostatic regulation of arterial pressure is not completely understood, but the following mechanisms of regulating arterial pressure have been well-characterized:

    These different mechanisms are not necessarily independent of each other, as indicated by the link between the RAS and aldosterone release. When blood pressure falls many physiological cascades commence in order to return the blood pressure to a more appropriate level.

  • The blood pressure fall is detected by a decrease in blood flow and thus a decrease in glomerular filtration rate .
  • Decrease in GFR is sensed as a decrease in Na+ levels by the macula densa.
  • The macula densa causes an increase in Na+ reabsorption, which causes water to follow in via osmosis and leads to an ultimate increase in plasma volume. Further, the macula densa releases adenosine which causes constriction of the afferent arterioles.
  • At the same time, the juxtaglomerular cells sense the decrease in blood pressure and release renin.
  • Renin converts angiotensinogen to angiotensin I .
  • Angiotensin I flows in the bloodstream until it reaches the capillaries of the lungs where angiotensin converting enzyme acts on it to convert it into angiotensin II.
  • Angiotensin II is a vasoconstrictor that will increase blood flow to the heart and subsequently the preload, ultimately increasing the cardiac output.
  • What Is Normal Blood Pressure And When Is Blood Pressure Considered To Be High

    One Quick Question: How Do You Calculate Mean Arterial Blood Pressure?

    Blood pressure is always measured on a number of different days and when you are at rest. If several of these measurements are too high, you are said to have high blood pressure, even if only one of the two either the systolic or the diastolic one is high. The medical term for high blood pressure is hypertension. In adults, blood pressure is considered to be normal under a systolic value of 140 mmHg and under a diastolic value of 90 mmHg.

    When taking your blood pressure for the first time, it makes sense to measure the blood pressure in both arms, because it’s sometimes high on only one side. The values that are higher are always the ones used for assessing blood pressure. After that it is enough to measure the blood pressure only in the arm that produced the higher reading. A person is considered to have high blood pressure if the systolic value is over 140 mmHg, the diastolic value is over 90 mmHg, or if both are higher than these readings.

    Table: Normal and high blood pressure readings

    systolic over 140 mmHg and/or diastolic over 90 mmHg

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    What Do Blood Pressure Readings Include

    The blood pressure equation is determined by two different factors: Systolic blood pressure, and Diastolic blood pressure. These two numbers can speak volumes about how the heart is functioning and the entire circulatory system. In more critical cases, doctors will also look at pulse pressure and vascular resistance. Here is what they do:

    Systolic Blood Pressure

    This number tells you about the left ventricle of the heart and the effort it is putting in to push blood throughout the body. When you see a blood pressure reading of 110/70, the 110 is the systolic pressure. 110 is a pretty good number and tells us the heart doesnt have to work too hard to get the blood out to the body. If you see a number higher than 120, the heart is having to work a little harder.

    Diastolic Blood Pressure

    This is the number that lets you know what the pressure is when your heart relaxes and refills with blood. On a blood pressure reading of 110/70, this is the bottom number. 70 tells you that your heart relaxes and refills just fine. If the number is 80 and up then your heart is working a little harder to relax and refill.

    Pulse Pressure

    Vascular Resistance


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