HOME

TheInfoList



OR:

Pulse pressure is the difference between systolic and diastolic
blood pressure Blood pressure (BP) is the pressure of Circulatory system, circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term ...
. It is measured in millimeters of mercury (mmHg). It represents the force that the heart generates each time it contracts. Healthy pulse pressure is around 40 mmHg. A pulse pressure that is consistently 60 mmHg or greater is likely to be associated with disease, and a pulse pressure of 50 mmHg or more increases the risk of
cardiovascular disease Cardiovascular disease (CVD) is any disease involving the heart or blood vessels. CVDs constitute a class of diseases that includes: coronary artery diseases (e.g. angina, heart attack), heart failure, hypertensive heart disease, rheumati ...
. Pulse pressure is considered low if it is less than 25% of the systolic. (For example, if the systolic pressure is 120 mmHg, then the pulse pressure would be considered low if it were less than 30 mmHg, since 30 is 25% of 120.) A very low pulse pressure can be a symptom of disorders such as
congestive heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome caused by an impairment in the heart's ability to fill with and pump blood. Although symptoms vary based on which side of the heart is affected, HF typically pr ...
.


Calculation

Pulse pressure is calculated as the difference between the systolic blood pressure and the diastolic blood pressure. The systemic pulse pressure is approximately proportional to
stroke volume In cardiovascular physiology, stroke volume (SV) is the volume of blood pumped from the ventricle (heart), ventricle per beat. Stroke volume is calculated using measurements of ventricle volumes from an Echocardiography, echocardiogram and subtra ...
, or the amount of blood ejected from the left ventricle during
systole Systole ( ) is the part of the cardiac cycle during which some chambers of the heart contract after refilling with blood. Its contrasting phase is diastole, the relaxed phase of the cardiac cycle when the chambers of the heart are refilling ...
(pump action) and inversely proportional to the compliance (similar to elasticity) of the
aorta The aorta ( ; : aortas or aortae) is the main and largest artery in the human body, originating from the Ventricle (heart), left ventricle of the heart, branching upwards immediately after, and extending down to the abdomen, where it splits at ...
. * ''Systemic pulse pressure'' (most commonly measured at the
brachial artery The brachial artery is the major blood vessel of the (upper) arm. It is the continuation of the axillary artery beyond the lower margin of teres major muscle. It continues down the ventral surface of the arm until it reaches the cubital fossa ...
in the upper arm using a
Sphygmomanometer A sphygmomanometer ( ), also known as a blood pressure monitor, blood pressure machine, or blood pressure gauge, is a device used to measure blood pressure, composed of an inflatable cuff to collapse and then release the artery under the cuff i ...
) = :e.g. normal 120 mmHg – 80 mmHg = 40 mmHg : low: : high: * ''Pulmonary pulse pressure'' is normally much lower than systemic blood pressure due to the higher compliance of the pulmonary system compared to the arterial circulation. It is measured by right heart catheterization or may be estimated by transthoracic echocardiography. Normal pulmonary artery pressure is 8 mmHg–20 mmHg at rest. :e.g. normal 15mmHg – 8mmHg = 7mmHg :high 25mmHg – 10mmHg = 15mmHg


Values and variation


Low (narrow) pulse pressure

A pulse pressure is considered abnormally low if it is less than 25% of the systolic value. If the pulse pressure is extremely low, i.e. 25 mmHg or less, it may indicate low stroke volume, as in
congestive heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome caused by an impairment in the heart's ability to fill with and pump blood. Although symptoms vary based on which side of the heart is affected, HF typically pr ...
. The most common cause of a low (narrow) pulse pressure is a drop in left ventricular stroke volume. In trauma, a low or narrow pulse pressure suggests significant blood loss. A narrow pulse pressure is also caused by aortic stenosis. This is due to the decreased stroke volume in aortic stenosis. Other conditions that can cause a narrow pulse pressure include blood loss (due to decreased blood volume), and cardiac tamponade (due to decreased filling time). In the majority of these conditions, systolic pressure decreases, while diastolic pressure remains normal, leading to a narrow pulse pressure. In the
Postural Orthostatic Tachycardia Syndrome Postural orthostatic tachycardia syndrome (POTS) is a condition characterized by an abnormally large increase in heart rate upon sitting up or standing. POTS is a disorder of the autonomic nervous system that can lead to a variety of symptoms, ...
it is postulated that declining venous return reduces stroke volume and frequently results in low pulse pressure. In extreme cases, patients experience a drop in pulse pressure to 0 mm Hg upon standing, rendering them practically pulseless while upright. This condition leads to significant morbidity, as many affected individuals struggle to remain standing.


High (wide) pulse pressure


Consistently high

A pulse pressure of 50 mmHg or more can increase the risk of heart disease, heart rhythm disorders, stroke and other cardiovascular diseases and events. Higher pulse pressures are also thought to play a role in eye and kidney damage from diseases such as diabetes. There are currently no drugs approved to lower pulse pressure, but some antihypertensive drugs have been shown to modestly lower pulse pressure, while other drugs used for
hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...
can actually have the counterproductive side effect of increasing resting pulse pressure. The aorta has the highest compliance in the arterial system due in part to a relatively greater proportion of elastin fibers versus
smooth muscle Smooth muscle is one of the three major types of vertebrate muscle tissue, the others being skeletal and cardiac muscle. It can also be found in invertebrates and is controlled by the autonomic nervous system. It is non- striated, so-called bec ...
and
collagen Collagen () is the main structural protein in the extracellular matrix of the connective tissues of many animals. It is the most abundant protein in mammals, making up 25% to 35% of protein content. Amino acids are bound together to form a trip ...
. This serves to dampen the pulsatile
ejection fraction An ejection fraction (EF) is the volumetric fraction (or portion of the total) of fluid (usually blood) ejected from a chamber (usually the heart) with each contraction (or heartbeat). It can refer to the cardiac atrium, cardiac ventricle, gall ...
of the left ventricle, thereby reducing the initial systolic pulse pressure, but slightly raising the subsequent diastolic phase. If the aorta becomes rigid, stiff and inextensible because of disorders, such as arteriosclerosis,
atherosclerosis Atherosclerosis is a pattern of the disease arteriosclerosis, characterized by development of abnormalities called lesions in walls of arteries. This is a chronic inflammatory disease involving many different cell types and is driven by eleva ...
or elastin defects (in connective tissue diseases), the pulse pressure would be higher due to less compliance of the aorta.See also: Central aortic blood pressure In hypertensive patients, a high pulse pressure can often be an indicator of conduit artery stiffness ( stiffness of the major arteries). When the arterial walls are stiffer (less compliant), the heart has to beat harder to overcome the resistance from the stiff arteries, resulting in an increased pulse pressure. Other conditions that can lead to a high pulse pressure include
aortic regurgitation Aortic regurgitation (AR), also known as aortic insufficiency (AI), is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle. As a conse ...
, aortic sclerosis, severe
iron-deficiency anemia Iron-deficiency anemia is anemia caused by a iron deficiency, lack of iron. Anemia is defined as a decrease in the number of red blood cells or the amount of hemoglobin in the blood. When onset is slow, symptoms are often vague such as Fatigue ( ...
(due to decreased blood viscosity), arteriosclerosis (due to loss of arterial compliance), and
hyperthyroidism Hyperthyroidism is a endocrine disease in which the thyroid gland produces excessive amounts of thyroid hormones. Thyrotoxicosis is a condition that occurs due to elevated levels of thyroid hormones of any cause and therefore includes hyperth ...
(due to increased systolic pressure), or arteriovenous malformation, among others. In aortic regurgitation, the aortic valve insufficiency results in the backward flow of blood (regurgitation) that is ejected during systole, and its return to the left ventricle during diastole. This increases the systolic blood pressure, and decreases the diastolic blood pressure, leading to a widened pulse pressure. A high pulse pressure combined with
bradycardia Bradycardia, also called bradyarrhythmia, is a resting heart rate under 60 beats per minute (BPM). While bradycardia can result from various pathological processes, it is commonly a physiological response to cardiovascular conditioning or due ...
and an irregular breathing pattern is associated with increased
intracranial pressure Intracranial pressure (ICP) is the pressure exerted by fluids such as cerebrospinal fluid (CSF) inside the skull and on the brain tissue. ICP is measured in millimeters of mercury ( mmHg) and at rest, is normally 7–15 mmHg for a supine adu ...
, a condition called Cushing's triad seen in people after head trauma with increased intracranial pressure. Common causes of widening pulse pressure include: *
Anemia Anemia (also spelt anaemia in British English) is a blood disorder in which the blood has a reduced ability to carry oxygen. This can be due to a lower than normal number of red blood cells, a reduction in the amount of hemoglobin availabl ...
* Aortic dissection *
Atherosclerosis Atherosclerosis is a pattern of the disease arteriosclerosis, characterized by development of abnormalities called lesions in walls of arteries. This is a chronic inflammatory disease involving many different cell types and is driven by eleva ...
* Arteriovenous fistula * Chronic aortic regurgitation * Aortic root aneurysm * Aortic root dilation * Beri beri * Distributive shock * Endocarditis *
Fever Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...
* Heart block * Increased intracranial pressure * Patent ductus arteriosus *
Pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...
* Thyrotoxicosis


From exercise

For most individuals, during aerobic exercise, the systolic pressure progressively increases while the diastolic pressure remains about the same, thereby widening the pulse pressure. These pressure changes facilitate an increase in
stroke volume In cardiovascular physiology, stroke volume (SV) is the volume of blood pumped from the ventricle (heart), ventricle per beat. Stroke volume is calculated using measurements of ventricle volumes from an Echocardiography, echocardiogram and subtra ...
and cardiac output at a lower
mean arterial pressure In medicine, the mean arterial pressure (MAP) is an average calculated blood pressure in an individual during a single cardiac cycle. Although methods of estimating MAP vary, a common calculation is to take one-third of the pulse pressure (the d ...
, enabling greater aerobic capacity and physical performance. The diastolic drop reflects a reduced systemic vascular resistance of the muscle
arteriole An arteriole is a small-diameter blood vessel in the microcirculation that extends and branches out from an artery and leads to capillary, capillaries. Arterioles have vascular smooth muscle, muscular walls (usually only one to two layers of smoo ...
s in response to the exercise.


Clinical significance

Pulse pressure has implications for both cardiovascular disease as well as many non-cardiovascular diseases. Even in people without other risk factors for cardiovascular disease, a consistently wide pulse pressure remains a significant independent predictor of all-cause, cardiovascular, and, in particular, coronary mortality. There is a positive correlation between high pulse pressure and markers of inflammation, such as c-reactive protein.


Cardiovascular disease and pulse pressure

Awareness of the effects of pulse pressure on morbidity and mortality is lacking relative to the awareness of the effects of elevated systolic and diastolic blood pressure. However, pulse pressure has consistently been found to be a stronger independent predictor of cardiovascular events, especially in older populations, than has systolic, diastolic, or mean arterial pressure. This increased risk has been observed in both men and women and even when no other cardiovascular risk factors are present. The increased risk also exists even in cases in which high pulse pressure is caused by diastolic pressure decreasing over time while systolic remains steady or even slightly decreases. A
meta-analysis Meta-analysis is a method of synthesis of quantitative data from multiple independent studies addressing a common research question. An important part of this method involves computing a combined effect size across all of the studies. As such, th ...
in 2000 showed that a 10 mmHg increase in pulse pressure was associated with a 20% increased risk of cardiovascular mortality, and a 13% increase in risk for all coronary end points. The study authors also noted that, while risks of cardiovascular end points do increase with higher systolic pressures, at any given systolic blood pressure the risk of major cardiovascular end points increases, rather than decreases, with lower diastolic levels. This suggests that interventions that lower diastolic pressure without also lowering systolic pressure (and thus lowering pulse pressure) could actually be counterproductive. People who simultaneously have a resting diastolic pressure of less than 60 mmHg and a pulse pressure of greater than 60 mmHg have double the risk of subclinical myocardial ischaemia and a risk of stroke that is 5.85 times greater than normal. For such patients, it may be dangerous to target a peripheral systolic pressure below 120 mmHg due to the fact that this could cause the diastolic blood pressure in the cerebral cortex in the brain to become so low that perfusion (blood flow) is insufficient, leading to white matter lesions. Nearly all coronary perfusion and more than half of cerebral perfusion occurs during diastole, thus a diastolic pressure that is too low can cause harm to both the heart and the brain. Increased pulse pressure is also a risk factor for the development of
atrial fibrillation Atrial fibrillation (AF, AFib or A-fib) is an Heart arrhythmia, abnormal heart rhythm (arrhythmia) characterized by fibrillation, rapid and irregular beating of the Atrium (heart), atrial chambers of the heart. It often begins as short periods ...
.


Effects of medications on pulse pressure

There are no drugs currently approved to lower pulse pressure. Although some anti-hypertensive drugs currently on the market may have the effect of modestly lowering pulse pressure, others may actually have the counterproductive effect of increasing pulse pressure. Among classes of drugs currently on the market, a 2020 review stated that thiazide diuretics and long‐acting nitrates are the two most effective at lowering pulse pressure. It has been hypothesized that vasopeptidase inhibitors and nitric oxide donors may be useful at lowering pulse pressure in patients with elevated pulse pressure by increasing the distensibility of the large arteries. There is evidence that
glyceryl trinitrate Nitroglycerin (NG) (alternative spelling nitroglycerine), also known as trinitroglycerol (TNG), nitro, glyceryl trinitrate (GTN), or 1,2,3-trinitroxypropane, is a dense, colorless or pale yellow, oily, explosive liquid most commonly produced by ...
, a nitric oxide donor, may be effective at lowering both pulse pressure and overall blood pressure in patients with acute and sub-acute stroke. A 2001 randomized, placebo-controlled trial of 1,292 males, compared the effects of
hydrochlorothiazide Hydrochlorothiazide, sold under the brand name Hydrodiuril among others, is a diuretic medication used to treat hypertension and swelling due to fluid build-up. Other uses include treating diabetes insipidus and renal tubular acidosis and t ...
(a thiazide diuretic),
atenolol Atenolol is a beta blocker medication primarily used to treat high blood pressure and angina, heart-associated chest pain. Although used to treat high blood pressure, it does not seem to improve mortality rate, mortality in those with the condi ...
(a
beta-blocker Beta blockers, also spelled β-blockers, are a class of medications that are predominantly used to manage abnormal heart rhythms ( arrhythmia), and to protect the heart from a second heart attack after a first heart attack (secondary prevention) ...
), captopril (an
ACE inhibitor Angiotensin-converting-enzyme inhibitors (ACE inhibitors) are a class of medication used primarily for the treatment of high blood pressure and heart failure. This class of medicine works by causing relaxation of blood vessels as well as a decr ...
), clonidine (a central α-agonist), diltiazem (a
calcium channel blocker Calcium channel blockers (CCB), calcium channel antagonists or calcium antagonists are a group of medications that disrupt the movement of calcium () through calcium channels. Calcium channel blockers are used as antihypertensive drugs, i.e., as ...
), and prazosin (an α-blocker) on pulse pressure and found that, after one year of treatment, hydrochlorothiazide was the most effective at lowering pulse pressure, with an average decrease of 8.6 mmHg. Captopril and atenolol were equal as least effective, with an average decrease of 4.1 mmHg. Clonidine (decrease of 6.3 mmHg), diltiazem (decrease of 5.5 mmHg), and prazosin (decrease of 5.0 mmHg) were intermediate.


Pulse pressure and sepsis

Diastolic blood pressure falls during the early stages of
sepsis Sepsis is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage of sepsis is followed by suppression of the immune system. Common signs and s ...
, causing a widening of pulse pressure. If sepsis becomes severe and hemodynamic compromise advances, the systolic pressure also decreases, causing a narrowing of pulse pressure. A pulse pressure of over 70 mmHg in patients with sepsis is correlated with an increased chance of survival. A widened pulse pressure is also correlated with an increased chance that someone with sepsis will benefit from and respond to IV fluids.


See also

* Cold pressor test * Prehypertension * Patent ductus arteriosus * Windkessel effect


References

{{DEFAULTSORT:Pulse Pressure Blood pressure Medical signs Cardiovascular physiology