Exercise 22 Blood Pressure Pulse And EKG Portland

Exercise 22 Blood Pressure & Pulse And EKG Portland Community College BI 232

Cardiac Cycle • Series of events that occur during one heartbeat. • Systole is a period of contraction in a heart chamber. • Diastole is a period of relaxation. 2

Auscultation • Closing of the valves causes the “lubb-dubb” heart sounds. • Isovolumetric contraction is when all heart valves are closed • Pressure builds and semilunar valves open and blood is pumped into great vessels. This is called ventricular ejection 3

Auscultation • The best locations to heart sounds are the auscultation areas for the heart. • These areas are named after the heart valve that can best be heard. 4

Blood Pressure • The forced exerted by blood on the walls of blood vessels. • A function of the pumping action of the heart and the resistance to flow as blood moves through the blood vessels. 5

Blood Pressure • In large elastic arteries, the BP fluctuates between a max. and min. value • Systolic pressure is the maximum pressure exerted on bv walls. • Diastolic pressure is the minimum level 6

Blood Pressure • Measured in units called millimeters of mercury (mm. Hg) • If the pressure in a bv is 95 mm Hg, it means that the force exerted by the blood will cause a column of mercury to rise 95 mm 7

Blood Pressure Cuffs • BP cuffs come in Large Adult different sizes. • Be sure to choose the one that is appropriate for the patient Infant 8

Measuring Blood Pressure • Most cuffs are marked with an O or an arrow. This should be placed near the artery. 9

Measuring Blood Pressure • Place the BP cuff snugly on the patient's arm. • Check to make sure you have found the artery. • Line the mark on the cuff up with the artery 10

Measuring Blood Pressure • Stethoscope: Note how the ear pieces slant slightly in one direction. • Make sure the ear pieces on the stethoscope are point away from you when you put them on. • Place stethoscope on the artery, tucked slightly under the cuff 11

Measuring Blood Pressure WRONG TECHNIQUE • The cuff should be placed at the level of the heart. • The patients arm (or leg) should be completely relaxed. • Resting on the table or in their lab is helpful 12 CORRECT TECHNIQUE

Inflate the Cuff • A Grasp the bulb so that your thumb can easily access the valve. • Turn the valve to the right to tighten it and pump up the cuff, turn it to the left to loosen it and deflate the cuff. 13

Measuring Blood Pressure • Pump up the cuff until the sphygmomanometer reads 180 to 200. • Loosen the valve to let a little of the air out. • Listen for the first heartbeat, that is the top number (systolic BP) • Continue to listen until there are no more heartbeats. The last beat you hear is the bottom number (diastolic BP) • Let the air all the way out and remove the cuff. 14

Video Demonstration for Measuring Blood Pressure • http: //www. uams. edu/csc/programs/orientati on/blood. Pressure/Taking. BP 1. mov 15

Normal Blood Pressure • Reference: • August 2004, National Heart Lung and Blood Institute – Diseases and Conditions Index • http: //www. nhlbi. nih. gov/health/dci/Diseases/Hbp/HBP_What. Is. html • For adults 18 and older who: • Are not on medicine for high blood pressure • Are not having a short-term serious illness • Do not have other conditions such as diabetes and kidney disease • Systolic BP: Less than 120 • Diastolic BP: Less than 80 16

Pre-Hypertension • Systolic BP: between 120 -139 • Diastolic BP: between 80 -89 • Examples: 118/82, 128/89, or 130/86 • If your blood pressure is in the pre-hypertension range, it is more likely that you will end up with high blood pressure unless you take action to prevent it. • Note: When systolic and diastolic blood pressures fall into different categories, the higher category should be used to classify blood pressure level. 17

Hypertension • Stage 1 • Systolic BP: between 140 -159 • Diastolic BP: between 90 -99 • Stage 2 • Systolic BP: 160 or higher • Diastolic BP: 100 or higher 18

Mean Arterial Pressure • When blood pressure is measured it is the arterial blood pressure that is recorded. • The difference between the systolic and diastolic pressures is called the pulse pressure (120 mm. Hg – 80 mm. Hg= 40 mm. Hg) • MAP= diastolic pressure + 1/3 pulse pressure • (80 mm. Hg + 1/3(40 mm. Hg)= 93. 3 mm. Hg) 19

Hypotension • Hypotension is a subnormal arterial pressure. • There is not enough pressure to adequately perfuse the tissues. • There is usually a mean arterial pressure (MAP) below 60 mm. Hg. • MAP= diastolic + 1/3(systolic-diastolic) Example: BP= 120/70 MAP= 70 + 1/3(120 -70)= 86. 6 • People who are chronically hypertensive may feel symptoms of hypotension if their mean arterial pressure drops by 40 mm. Hg, even if the absolute value is still 20 over 60.

Pulse • The rhythmic expansion and recoil of the arteries is known as the pulse. • Can be found in various locations • Diminish in smaller arteries and are absent in capillaries and veins 21

Pulse Radial Pulse Carotid Pulse Brachial Pulse 22

Pulse Posterior Tibial Pulse Dorsalis Pedis Pulse 23

Cardiac Conduction System • The heart contains a network of specialized cardiac muscle cells, which is able to generate and conduct action potentials without neuronal or hormonal stimulation. 24

Cardiac Conduction System • Sinoatrial (SA) node is the pacemaker of the heart • Atrioventricular (AV) node when the AP reaches the AV node, atrial muscle cells repolarized and relax 25

Cardiac Conduction System • From the AV node impulses enter the ventricles by spreading along the AV bundle to left and right bundle branches and then to Purkinje fibers. • The Purkinje fibers deliver impulses to cardiac muscle cells leading to contraction 26

Electrocardiography (ECG) • Faint traces of the electrical activity occurring along the heart wall spread through the rest of the body. • These electrical changes can be detected by electrodes on the skin 27

EKG Waveform 28

P wave • The P wave indicates the depolarization of the atria just prior to the beginning of atrial contraction or systole 29

QRS complex (QRS interval) • Represents the depolarization of the ventricles which precedes ventricular systole. 30

T wave • Results from ventricular depolarization, which occurs before ventricular relaxation or diastole. 31

The End 32