diastolic blood pressure

(noun)

The lowest pressure within the bloodstream, occurring between heartbeats because of a diastole.

Related Terms

Examples of diastolic blood pressure in the following topics:

  • Cardiac Cycle

    • Complete cardiac diastole occurs after systole.
    • Thus, there are two types of measurable blood pressure: systolic during contraction and diastolic during relaxation.
    • Systolic blood pressure is always higher than diastolic blood pressure, generally presented as a ratio in which systolic blood pressure is over diastolic blood pressure.
    • For example, 115/75 mmHg would indicated a systolic blood pressure of 115 mmHg and a diastolic blood pressure or 75 mmHG.
    • The normal range for blood pressure is between 90/60 mmHg and 120/80 mmHg.

  • Measuring Blood Pressure

    • Measurement of blood pressure includes systolic pressure during cardiac contraction and diastolic pressure during cardiac relaxation.
    • Blood pressure is the pressure blood exerts on the arterial walls.
    • It is recorded as two readings: the systolic blood pressure (the top number) occurs during cardiac contraction, and the diastolic blood pressure or resting pressure (the bottom number), occurs between heartbeats when the heart is not actively contracting.
    • A normal blood pressure is about 120 mmHg systolic over 80 mmHg diastolic.
    • A blood pressure cuff and associated monitor used for determining systolic and diastolic pressures within an artery.

  • Introduction to Blood Pressure

    • Blood pressure is a vital sign reflecting the pressure exerted on blood vessels when blood is forced out of the heart during contraction.
    • Blood pressure is the pressure that blood exerts on the wall of the blood vessels.
    • Two mechanisms take place in the heart: diastole and systole.
    • Systolic pressure is thus the pressure that your heart emits when blood is forced out of the heart and diastolic pressure is the pressure exerted when the heart is relaxed.
    • During each heartbeat, blood pressure varies between a maximum (systolic) and a minimum (diastolic) pressure.

  • Extremes in Blood Pressure

    • Chronically elevated blood pressure is called hypertension, while chronically low blood pressure is called hypotension.
    • In healthy adults, physiological blood pressure should fall between the range of 100-140 mmHg systolic and 60-90 mmHg diastolic.
    • Hypertension or high blood pressure, sometimes called arterial hypertension, is a chronic medical condition in which the blood pressure in the arteries is elevated above 140/90 mmHg.
    • Even moderate elevation of arterial blood pressure is associated with a shortened life expectancy.
    • However, blood pressure is considered too low only if noticeable symptoms are present.

  • Hypertension

    • Hypertension is elevated blood pressure, clinically defined as at or greater than 140/90 (systolic/diastolic) mm/Hg.
    • Hypertension (HTN) or high blood pressure, sometimes called arterial hypertension, is a chronic medical condition in which the blood pressure in the arteries is elevated.
    • Blood pressure involves two measurements, systolic and diastolic, which depend on whether the heart muscle is contracting (systole) or relaxed between beats (diastole).
    • Normal blood pressure at rest is within the range of 100-140mmHg systolic (top reading) and 60-90mmHg diastolic (bottom reading).
    • Persistant high blood pressure can affect many areas of the body.

  • Arterial Blood Pressure

    • The measurement of blood pressure without further specification usually refers to the systemic arterial pressure, defined as the pressure exerted by circulating blood upon the walls of blood vessels.
    • A person's blood pressure is usually expressed in terms of the systolic pressure over diastolic pressure and is measured in millimeters of mercury (mmHg), for example 140/90.
    • In the past, most attention was paid to diastolic pressure, but now we know that both high systolic pressure and high pulse pressure (the numerical difference between systolic and diastolic pressures) are also risk factors for disease.
    • In some cases, a decrease in excessive diastolic pressure can actually increase risk, probably due to the increased difference between systolic and diastolic pressures.
    • If systolic blood pressure is elevated (>140) with a normal diastolic blood pressure (<90), it is called "isolated systolic hypertension" and may present a health concern.

  • Checking Circulation

    • Checking circulation involves measurement of blood pressure and pulse through a variety of invasive and noninvasive methods.
    • For each heartbeat, blood pressure varies between systolic and diastolic pressures.
    • Diastolic pressure is minimum pressure in the arteries, which occurs near the beginning of the cardiac cycle when the ventricles are filled with blood.
    • The pressure at which this sound is first heard is the systolic blood pressure.
    • The cuff pressure is further released until no sound can be heard (fifth Korotkoff sound), at the diastolic arterial pressure.

  • Operation of Atrioventricular Valves

    • Valves open or close based on pressure differences across the valve.
    • The subvalvular apparatus has no effect on the opening and closing of the valves, which is caused entirely by the pressure gradient of blood across the valve as blood flows from high pressure to low pressure areas.
    • The relaxation of the ventricular myocardium and the contraction of the atrial myocardium cause a pressure gradient that allows for rapid blood flow from the left atrium into the left ventricle across the mitral valve.
    • Atrial systole (contraction) increases the pressure in the atria, while ventricular diastole (relaxation) decreases the pressure in the ventricle, causing pressure-induced flow of blood across the valve.
    • Blood passes through the tricuspid valve the same as it does through the bicuspid valve, based on a pressure gradient from high pressure to low pressure during systole and diastole.

  • Artery Function

    • Arteries are high-pressure blood vessels that carry oxygenated blood away from the heart to all other tissues and organs.
    • Arteries are blood vessels that carry blood away from the heart under pressure.
    • In arteries, the tunica media, which contains smooth muscle cells and elastic tissue, is thicker than that of veins so it can modulate vessel caliber and thus control and maintain blood pressure.
    • Arterial pressure varies between the peak pressure during heart contraction, called the systolic pressure, and the minimum or diastolic pressure between contractions, when the heart expands and refills.
    • The pressure in the arterial system decreases steadily, highest in the aorta and lowest in the venous system, as blood approaches the heart after delivery of oxygen to tissues in the systemic circulation.

  • Venous Blood Pressure

    • Blood pressure generally refers to the arterial pressure in the systemic circulation.
    • Central venous pressure, a good approximation of right atrial pressure, which is a major determinant of right ventricular end diastolic volume.
    • Portal venous pressure or the blood pressure in the portal vein.
    • Jet pilots wear pressurized suits to help maintain their venous return and blood pressure, since high-speed maneuvers increase venous pooling in the legs.
    • This ensures that end diastolic volumes are maintained and that the brain will receive adequate blood, preventing loss of consciousness.