Pulse pressure is the difference between
systolic and
diastolic
Diastole ( ) is the relaxed phase of the cardiac cycle when the chambers of the heart are re-filling with blood. The contrasting phase is systole when the heart chambers are contracting. Atrial diastole is the relaxing of the atria, and ventricu ...
blood pressure.
It is measured in
millimeters of mercury
A millimetre of mercury is a manometric unit of pressure, formerly defined as the extra pressure generated by a column of mercury one millimetre high, and currently defined as exactly pascals. It is denoted mmHg or mm Hg.
Although not an S ...
(mmHg). It represents the force that the heart generates each time it contracts. Resting blood pressure is normally approximately 120/80 mmHg, which yields a pulse pressure of approximately 40 mm Hg.
Causes
High
High sodium intake may cause high pulse pressure.
Calculation
Pulse pressure is the (higher) systolic blood pressure minus the (lower) 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 left ventricle per beat. Stroke volume is calculated using measurements of ventricle volumes from an echocardiogram and subtracting the volume of the blood i ...
, or the amount of blood ejected from the
left ventricle
A ventricle is one of two large chambers toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium, an adjacent chamber in the uppe ...
during
systole
Systole ( ) is the part of the cardiac cycle during which some chambers of the heart contract after refilling with blood. The term originates, via New Latin, from Ancient Greek (''sustolē''), from (''sustéllein'' 'to contract'; from ''sun ...
(pump action) and inversely proportional to the
compliance (similar to
Elasticity) of the
aorta
The aorta ( ) is the main and largest artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries (the common iliac arteries). The aorta distributes o ...
.
The aorta has the highest compliance in the arterial system due in part to a relatively greater proportion of elastin fibers versus smooth muscle and collagen. This serves the important function of damping the pulsatile (
max pump pressure) output of the left ventricle, thereby reducing the initial systolic pulse pressure but slightly raising the subsequent diastolic phase (a period rather similar to
Dwell time). If the aorta becomes rigid because of disorders such as
arteriosclerosis
Arteriosclerosis is the thickening, hardening, and loss of elasticity of the walls of arteries. This process gradually restricts the blood flow to one's organs and tissues and can lead to severe health risks brought on by atherosclerosis, which ...
or
atherosclerosis
Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheroma, atheromatous plaque. At onset there are usu ...
, the pulse pressure would be very high because the aorta becomes less compliant due to the formation of rigid
lesion
A lesion is any damage or abnormal change in the tissue of an organism, usually caused by disease or trauma. ''Lesion'' is derived from the Latin "injury". Lesions may occur in plants as well as animals.
Types
There is no designated classifi ...
s to the (otherwise flexible) aorta wall.
* Systemic pulse pressure (SPP) (usually
measured at upper right arm artery) = P
systolic - P
diastolic
:e.g. normal 120mmHg - 80mmHg = 40mmHg
: low 107mmHg - 80mmHg = 27mmHg
: high 160mmHg - 80mmHg = 80mmHg
* Pulmonary pulse pressure (PAP) (Heart-Lung), is normally significant lower than systemic blood pressure due to the higher compliance of the pulmonary system compared to systemic circulation. It is measured by
right
Rights are law, legal, social, or ethics, ethical principles of Liberty, freedom or entitlement; that is, rights are the fundamental normative rules about what is allowed of people or owed to people according to some legal system, social convent ...
heart
catheterization or may be estimated by
transthoracic echocardiography
An echocardiography, echocardiogram, cardiac echo or simply an echo, is an ultrasound of the heart.
It is a type of medical imaging of the heart, using standard ultrasound or Doppler ultrasound.
Echocardiography has become routinely used in t ...
(TTE) Normal pulmonary artery pressure is between 8mmHg -20 mm Hg at rest.
: e.g. normal 15mmHg - 8mmHg = 7mmHg
: high 25mmHg - 10mmHg = 15mmHg
Values and variation
Low (narrow)
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 (insufficient preload leading to reduced cardiac output).
A narrow pulse pressure is also caused by
aortic valve stenosis and
cardiac tamponade
Cardiac tamponade, also known as pericardial tamponade (), is the buildup of fluid in the pericardium (the sac around the heart), resulting in compression of the heart. Onset may be rapid or gradual. Symptoms typically include those of obstructi ...
.
Systemic
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, the cause may be low stroke volume, as in
Congestive Heart Failure
Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, ...
and/or
cardiogenic shock.
High (wide)
From exercise
Usually, the resting
pulse
In medicine, a pulse represents the tactile arterial palpation of the cardiac cycle (heartbeat) by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed near the surface of the body, such as at the n ...
pressure in healthy adults, sitting position, is about 30–40
mmHg. The pulse pressure increases with exercise due to increased stroke volume, healthy values being up to pulse pressures of about 100 mmHg, simultaneously as
systemic vascular resistance drops during exercise. In healthy individuals the pulse pressure will typically return to normal within about 11 minutes.
For most individuals, during aerobic exercise, the
systolic pressure progressively increases while the
diastolic
Diastole ( ) is the relaxed phase of the cardiac cycle when the chambers of the heart are re-filling with blood. The contrasting phase is systole when the heart chambers are contracting. Atrial diastole is the relaxing of the atria, and ventricu ...
remains about the same. In some very aerobically athletic individuals, for example distance runners, the
diastolic
Diastole ( ) is the relaxed phase of the cardiac cycle when the chambers of the heart are re-filling with blood. The contrasting phase is systole when the heart chambers are contracting. Atrial diastole is the relaxing of the atria, and ventricu ...
will progressively fall as the
systolic increases. This behavior facilitates a much greater increase in
stroke volume
In cardiovascular physiology, stroke volume (SV) is the volume of blood pumped from the left ventricle per beat. Stroke volume is calculated using measurements of ventricle volumes from an echocardiogram and subtracting the volume of the blood i ...
and
cardiac output
In cardiac physiology, cardiac output (CO), also known as heart output and often denoted by the symbols Q, \dot Q, or \dot Q_ , edited by Catherine E. Williamson, Phillip Bennett is the volumetric flow rate of the heart's pumping output: t ...
at a lower
mean arterial pressure
In medicine, the mean arterial pressure (MAP) is an average blood pressure in an individual during a single cardiac cycle. MAP is altered by cardiac output and systemic vascular resistance.
Testing
Mean arterial pressure can be measured dire ...
and enables much greater aerobic capacity and physical performance. The diastolic drop reflects a much greater fall in 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 capillaries.
Arterioles have muscular walls (usually only one to two layers of smooth muscle cells) and are the primar ...
s in response to the exercise (a greater proportion of
red versus white muscle tissue). Individuals with larger BMIs due to increased muscle mass (bodybuilders) have also been shown to have lower diastolic pressures and larger pulse pressures.
Consistently high
If the usual resting pulse pressure is consistently greater than 100 mmHg, the most likely basis is
stiffness of the major arteries,
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 conseq ...
(a leak in the
aortic valve
The aortic valve is a valve in the heart of humans and most other animals, located between the left ventricle and the aorta. It is one of the four valves of the heart and one of the two semilunar valves, the other being the pulmonary valve. The ...
),
arteriovenous malformation (an extra path for blood to travel from a high pressure artery to a low pressure vein without the gradient of a capillary bed),
hyperthyroidism
Hyperthyroidism is the condition that occurs due to excessive production of thyroid hormones by the thyroid gland. Thyrotoxicosis is the condition that occurs due to excessive thyroid hormone of any cause and therefore includes hyperthyroidism ...
or some combination. (A chronically increased stroke volume is also a technical possibility, but very rare in practice.) While some drugs for hypertension have the side effect of increasing resting pulse pressure irreversibly, other antihypertensive drugs, such as
ACE Inhibitors
Angiotensin-converting-enzyme inhibitors (ACE inhibitors) are a class of medication used primarily for the treatment of high blood pressure and heart failure. They work by causing relaxation of blood vessels as well as a decrease in blood volume ...
, have been shown to lower pulse pressure. A high resting pulse pressure is harmful and tends to accelerate the normal aging of body organs, particularly the heart, the brain and kidneys. A high pulse pressure combined with
bradycardia 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 adult ...
and should be reported to a physician immediately. This is known as
Cushing's triad Cushing reflex (also referred to as the vasopressor response, the Cushing effect, the Cushing reaction, the Cushing phenomenon, the Cushing response, or Cushing's Law) is a physiological nervous system response to increased intracranial pressure (IC ...
and can be seen in patients after head trauma related to increased intracranial pressure.
Some common causes of widening pulse pressure :
*
Anemia
Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, th ...
*
Aortic dissection
Aortic dissection (AD) occurs when an injury to the innermost layer of the aorta allows blood to flow between the layers of the aortic wall, forcing the layers apart. In most cases, this is associated with a sudden onset of severe chest or ...
*
Atherosclerosis
Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheroma, atheromatous plaque. At onset there are usu ...
*
Arteriovenous fistula
An arteriovenous fistula is an abnormal connection or passageway between an artery and a vein. It may be congenital, surgically created for hemodialysis treatments, or acquired due to pathologic process, such as trauma or erosion of an arterial ...
*
Chronic aortic regurgitation
*
Aortic root aneurysm
* Aortic root dilation
*
Beri beri
*
Distributive shock
Distributive shock is a medical condition in which abnormal distribution of blood flow in the smallest blood vessels results in inadequate supply of blood to the body's tissues and organs. It is one of four categories of shock, a condition wher ...
*
Endocarditis
Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves. Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or the ...
*
Fever
Fever, also referred to as pyrexia, is defined as having a body temperature, temperature above the human body temperature, normal range due to an increase in the body's temperature Human body temperature#Fever, set point. There is not a single ...
*
Heart block
Heart block (HB) is a disorder in the heart's rhythm due to a fault in the natural pacemaker. This is caused by an obstruction – a block – in the electrical conduction system of the heart. Sometimes a disorder can be inherited. Despite the se ...
*
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 adult. Th ...
[
* ]Patent ductus arteriosus
''Patent ductus arteriosus'' (PDA) is a medical condition in which the ''ductus arteriosus'' fails to close after birth: this allows a portion of oxygenated blood from the left heart to flow back to the lungs by flowing from the aorta, which has ...
* Pregnancy
Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occurs by sexual intercourse, but ca ...
* Thyrotoxicosis
Hyperthyroidism is the condition that occurs due to excessive production of thyroid hormones by the thyroid gland. Thyrotoxicosis is the condition that occurs due to excessive thyroid hormone of any cause and therefore includes hyperthyroidism. ...
Clinical signficance
Heart disease
A meta-analysis
A meta-analysis is a statistical analysis that combines the results of multiple scientific studies. Meta-analyses can be performed when there are multiple scientific studies addressing the same question, with each individual study reporting me ...
study conducted in 2000, suggested that a high pulse pressure is an important risk factor for heart disease
Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, hea ...
. The study, which combined the results of several studies of 8,000 elderly patients in all, found that a 10 mm Hg increase in pulse pressure increased the risk of major cardiovascular complications and mortality by nearly 20%. Heightened pulse pressure is also a risk factor for the development of atrial fibrillation. The authors of the meta-analysis suggest that this helps to explain the apparent increase in risk sometimes associated with low diastolic pressure, and warn that some medications for high blood pressure may actually increase the pulse pressure and the risk of heart disease.
Psychotic disorders
In a large study (N=1289) among patients with psychotic disorders researchers found that, when controlling for patients' age and cardiovascular disease status, body mass index (BMI) and employment status predicted the likelihood of having elevated pulse pressure. Further, it was also found that elevated pulse pressure was (above 60 mm/Hg) mainly associated with the physical domains of functioning such as mobility and self-care.
Self measurement
Pulse pressure readings can be taken on a home blood pressure monitoring device. These devices display systolic and diastolic blood pressure (from which pulse pressure can be calculated) and pulse rate readings. Monitoring at home can be helpful to a medical provider in interpreting in-office results and progression of disease processes.
Treatment
If the patient suffers from elevated pulse pressure, treatment may include medications that address this factor, such as an angiotensin-converting enzyme inhibitor (ACE inhibitor
Angiotensin-converting-enzyme inhibitors (ACE inhibitors) are a class of medication used primarily for the treatment of hypertension, high blood pressure and heart failure. They work by causing relaxation of blood vessels as well as a decrease i ...
).
See also
* Mean arterial pressure
In medicine, the mean arterial pressure (MAP) is an average blood pressure in an individual during a single cardiac cycle. MAP is altered by cardiac output and systemic vascular resistance.
Testing
Mean arterial pressure can be measured dire ...
* Cold pressor test
The cold pressor test is a cardiovascular test performed by immersing the hand into an ice water container, usually for one minute, and measuring changes in blood pressure and heart rate. These changes relate to vascular response and pulse excitab ...
* Hypertension
Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high bl ...
* Prehypertension
Prehypertension, also known as high normal blood pressure and borderline hypertensive (BH), is a medical classification for cases where a person's blood pressure is elevated above optimal or normal, but not to the level considered hypertension (hi ...
* Antihypertensive
Antihypertensives are a class of drugs that are used to treat hypertension (high blood pressure). Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke and myocardial infarction. Evidence suggests tha ...
* Patent ductus arteriosus
''Patent ductus arteriosus'' (PDA) is a medical condition in which the ''ductus arteriosus'' fails to close after birth: this allows a portion of oxygenated blood from the left heart to flow back to the lungs by flowing from the aorta, which has ...
References
{{DEFAULTSORT:Pulse Pressure
Medical signs
Cardiovascular physiology