Mean arterial pressure

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The mean arterial pressure (MAP) is a term used in medicine to describe a national average blood pressure in an individual.^[1] It is defined as the average arterial pressure during a single cardiac cycle.

Contents 1 Calculation 2 Estimation 3 Clinical significance 4 See also 5 References

[edit] Calculation

Mean arterial pressure can be determined from:^[2]

where:

• CO is cardiac output
• SVR is systemic vascular resistance
• CVP is central venous pressure and usually small enough to be neglected in this formula.

[edit] Estimation

At normal resting heart rates MAP can be approximated using the more easily measured systolic and diastolic pressures, SP and DP:^[3][4][5]

or equivalently

or equivalently

where PP is the pulse pressure, SP − DP

At high heart rates MAP is more closely approximated by the arithmetic mean of systolic and diastolic pressures because of the change in shape of the arterial pressure pulse.

[edit] Clinical significance

MAP is considered to be the perfusion pressure seen by organs in the body.

It is believed that a MAP that is greater than 60 mmHg is enough to sustain the organs of the average person.

If the MAP falls significantly below this number for an appreciable time, the end organ will not get enough blood flow, and will become ischemic.

[edit] See also

• Blood pressure
• Hypertension
• Pulse pressure

[edit] References

v • d • e Cardiovascular system, physiology: cardiovascular physiology Heart Volumes Stroke volume = End-diastolic volume - End-systolic volume Cardiac output = Heart rate * Stroke volume Afterload · Preload Frank-Starling law of the heart · Cardiac function curve · Venous return curve Aortic valve area calculation · Ejection fraction · Cardiac index Interaction diagrams Cardiac cycle · Wiggers diagram · Pressure volume diagram Tropism Chronotropic (Heart rate) · Dromotropic (Conduction velocity) · Inotropic (Contractility) · Batmotropic (Excitability) · Lusitropic (Relaxation) Conduction system / Cardiac electrophysiology Cardiac action potential (Atrial action potential, Ventricular action potential) · Effective refractory period · Pacemaker potential · QT interval Other Ventricular remodeling Hemodynamics Blood flow Compliance · Vascular resistance (Total peripheral resistance) · Pulse · Perfusion Blood pressure Pulse pressure (Systolic - Diastolic) · Mean arterial pressure Central venous pressure/right atrial pressure → Right ventricular pressure → Pulmonary artery pressure → Pulmonary wedge pressure/left atrial pressure → Left ventricular pressure → Aortic pressure Jugular venous pressure Portal venous pressure Regulation of BP Baroreflex · Kinin-kallikrein system · Renin-angiotensin system · Vasoconstrictors/Vasodilators · Autoregulation (Myogenic mechanism, Tubuloglomerular feedback)