pulse rate

Examples of pulse rate in the following topics:

• Pulse

  • Pulse is a measurement of heart rate by touching and counting beats at several body locations, typically at the wrist radial artery.
  • Pulse is often used as an equivalent of heart rate due to the relative ease of measurement; heart rate can be measured by listening to the heart directly through the chest, traditionally using a stethoscope.
  • Pulse varies with age; a newborn or infant can have a heart rate of about 130-150 bpm.
  • The heart rate may be greater or less than the pulse rate depending upon physiologic demand.
  • In this case, the heart rate is determined by auscultation or audible sounds at the heart apex, not the pulse.

• Checking Circulation

  • While a simple pulse rate measurement can be achieved by anyone, trained medical staff are capable of much more accurate measurements.
  • Where more accurate or long-term measurements are required, pulse rate, pulse deficits, and much more physiologic data are readily visualized by the use of one or more arterial catheters connected to a transducer and oscilloscope.
  • The rate of the pulse is observed and measured by tactile or visual means on the outside of an artery and recorded as beats per minute (BPM).
  • Heart rate can be measured by listening to the heart directly though the chest, traditionally using a stethoscope.
  • Along with body temperature, respiratory rate, and pulse rate, blood pressure is one of the four main vital signs routinely monitored by medical professionals and healthcare providers.

• Cardiac Cycle

  • Heart rate is a term used to describe the frequency of the cardiac cycle.
  • These properties allow the arterial wall to distend when pressure increases, resulting in a pulse that can be detected by touch.
  • Exercise, environmental stress, or psychological stress can cause the heart rate to increase above the resting rate.
  • The pulse is the most straightforward way of measuring the heart rate, but it can be a crude and inaccurate measurement when cardiac output is low.
  • In these cases (as happens in some arrhythmias), there is little pressure change and no corresponding change in pulse, and the heart rate may be considerably higher than the measured pulse.

• Arrhythmia

  • The sinoatrial node is a single specialized location in the atrium which has a higher automaticity (a faster pacemaker) than the rest of the heart and, therefore, is usually responsible for setting the heart rate and initiating each heart beat.
  • The impulse then spreads through both ventricles causing a synchronized contraction of the heart muscle and, thus, the pulse.
  • In adults the normal resting heart rate ranges from 60 to 80 beats per minute.
  • The resting heart rate in children is much faster.
  • Arrhythmias - types: Arrhythmia may be classified by rate (normal, tachycardia, bradycardia), or mechanism (automaticity, reentry, fibrillation).

• Cardiopulmonary Resuscitation (CPR)

  • CPR involves chest compressions at least 5 cm deep and at a rate of at least 100 per minute in an effort to create artificial circulation by manually pumping blood through the heart.
  • If a person still has a pulse, but is not breathing (respiratory arrest), artificial respirations may be more appropriate, but due to the difficulty people have in accurately assessing the presence or absence of a pulse, CPR guidelines recommend that lay persons should not be instructed to check the pulse, while giving health care professionals the option to check a pulse.
  • A 1996 study published in the New England Journal of Medicine showed that CPR success rates in television shows were 75% for immediate circulation, and 67% survival to discharge.
  • When educated on the actual survival rates, the proportion of patients over 60 years of age desiring CPR should they suffer a cardiac arrest drops from 41% to 22%.

• Signs and Symptoms of Shock

  • Typical symptoms of shock include elevated but weak heart rate, low blood pressure, and poor organ function, typically observed as low urine output, confusion or loss of consciousness.
  • While a fast heart rate is common, those on beta blockers and those who are athletic may have a normal or slow heart rate.
  • This leads to a rapid, weak pulse due to decreased blood flow combined with tachycardia, stimulation of vasoconstriction, and cool, clammy skin.
  • With anaphylaxis, hives may present on the skin, and there may localized edema, especially around the face, and weak and rapid pulse.
  • The symptoms of neurogenic shock are distinct from those of classical shock, as the heart rate slows and and superficial vessels vasodilate and warm the skin.

• Introduction to Blood Pressure

  • The rate of mean blood flow depends on the resistance to flow presented by the blood vessels.
  • Blood pressure and pulse, or the vital signs, are measured as indicators of several aspects of cardiovascular health.

• Asthma

  • Asthma is clinically classified according to the frequency of symptoms, forced expiratory volume over one second (FEV1), and peak expiratory flow rate.
  • Signs which occur during an asthma attack include the use of accessory muscles of respiration (sternocleidomastoid and scalene muscles of the neck), there may be a paradoxical pulse (a pulse that is weaker during inhalation and stronger during exhalation), and over-inflation of the chest.
  • Peak flow meters are used to measure peak expiratory flow rate.

• Medical Imaging

  • Fluoroscopy produces real-time images of internal structures of the body in a similar fashion to radiography, but employs a constant input of x-rays, at a lower dose rate.
  • The MRI machine emits an RF (radio frequency) pulse that specifically binds only to hydrogen.
  • The pulse makes the protons in that area absorb the energy needed to make them spin in a different direction.
  • The RF pulse makes the one or two extra unmatched protons per million spin at a specific frequency, in a specific direction.

• Types of Shock

  • Typical symptoms include a rapid, weak pulse due to decreased blood flow combined with tachycardia, cool, clammy skin, and rapid and shallow breathing.
  • Neurogenic shock arises due to damage to the central nervous system, which impairs cardiac function by reducing heart rate and loosening the blood vessel tone, resulting in severe hypotension.