Blood pressure & Pulse

Blood Pressure

•The pressure of the blood against the walls of the arteries.

•Blood pressure results from two forces. ▫One is created by the heart as it pumps

blood into the arteries and through the circulatory system.

▫The other is the force of the arteries as they resist the blood flow Arterioles have greatest resistance

Blood Pressure•Systolic Blood

Pressure

•Diastolic Blood Pressure

•Measured in mm Hg

Systolic Pressure

•The number on top•The pressure inside your blood vessels at

the moment your heart beats. •Normal > 120 mm Hg

Diastolic Pressure

•The number on the bottom•Measures the pressure in your blood

vessels between heartbeats, when your heart is resting.

•Normal >80 mm Hg

Measuring Blood Pressure

•Sphygmomanometer – Stethoscope•Korotkoff sounds

▫sounds one is listening for when measuring blood pressure

▫detected by listening with a stethoscope placed over the brachial (arm) artery just below a blood pressure cuff

(Reference What are Korotkoff Sounds retrieved from http://www.lifeclinic.com/focus/blood/articleView.asp?MessageID=187)

Measuring Blood Pressure

•Procedure▫Blood Pressure Cuff Inflated▫Gradually deflated from a pressure high

enough to obstruct the artery and stop the blood flowing

▫Listen for Korotkoff sounds First sound heard-Systolic Pressure Last sound heard- Diastolic Pressure

•Difference in Systolic and Diastolic called Pulse Pressure

This chart reflects blood pressure categories defined by the American Heart Association.Blood Pressure

CategorySystolic

mm Hg (upper #)  Diastolic

mm Hg (lower #)

Normal  less than 120 and less than 80

Prehypertension 120 – 139 or 80 – 89

High Blood Pressure

(Hypertension) Stage 1

140 – 159 or 90 – 99

High Blood Pressure

(Hypertension) Stage 2

160 or higher or 100 or higher

Hypertensive Crisis

(Emergency care needed)

Higher than 180 or Higher than 110

Factors Effecting Blood Pressure•Average is 120/80 •Factors

▫Cardiac Output Volume of blood pumped out ventricles

▫Blood volume (5 liters for avg adult) Volume of blood circulating body per minute

▫Blood Velocity Speed of blood flow

▫Peripheral Resistance Resistance of blood flow

Pulse

•Alternate expansion and recoil of an artery•Caused by the intermittent injections of blood from the heart and elasticity of arterial walls•Taken from the Radial Artery•Pulse: 60-100 bpm

Pulse

•Pulse points (Fig. 19-24)▫Radial artery▫Temporal artery▫Common carotid artery▫Facial artery▫Brachial artery▫Popliteal artery▫Posterior tibial artery▫Dorsalis pedis artery

Abnormal Heart Rhythms

•Arrhythmias•Tachycardia = rapid heartbeat ( > 100

BPM)•Bradycardia = slow heartbeat ( < 60

BPM)•Fibrillation = rapid, uncoordinated

unsynchronized heart rate. Atria (not serious) Ventricles (deadly)

Effects on Heart Rate

•What sets heart rate?•Sympathetic

▫Chiefly Vagus▫Stimulant ▫Release norepinephrine

•Parasympathetic▫Cardiac Verve▫Inhibitory▫Release Acetylcholine

Heart Sounds

•Heart Sounds Website