chapter 16 cardiac care skills. copyright © 2007 thomson delmar learning. all rights reserved.2...

Chapter 16

Cardiac Care Skills

Copyright © 2007 Thomson Delmar Learning. ALL RIGHTS RESERVED. 2

Electrical Conductionof the Heart

• Two phases of the cardiac cycle are contraction and relaxation– Heart beats during contraction, pumping blood

to the body– Heart rests and recovers during relaxation

• Understanding normal heart conduction means understanding a cardiac rhythm


The Pacemaker

• Electrical activity resulting in a heartbeat begins in the pacemaker

• Any heart tissue can function as the pacemaker

• Normal pacemaker is in the right atrium, called sinoatrial node (SA node)

• SA node fires 60 to 100 times each minute


The Atrioventricular Node

• AV node is located on the bottom of the atrium, just above the ventricles

• AV node conducts the electrical impulse into the ventricles

• If AV node acts as pacemaker, it sends impulses at 40 to 60 beats per minute


The Ventricles

• Ventricles: bottom chambers of heart– Impulse travels through right and left bundle

branches and Purkinje fibers– Structures work together and cause ventricles

to contract– Contraction results in a heartbeat forcing blood

throughout the body


The Ventricles

• Ventricles can function as the pacemaker at a rate of 20 to 40 beats per minute


Monitoring the Heartbeat

• P wave – Pacemaker firing and sending impulse

through the atria

• PR interval– Length of time it takes impulse to travel

through the atrium and AV node


Monitoring the Heartbeat

• QRS complex – Impulse traveling through the ventricles

• T wave– Resting and recovery phase of the heart


The Twelve Lead ECG

• Lead I – Right arm negative; left arm positive

• Lead II – Left leg positive; right leg negative


The Twelve Lead ECG

• Lead III– Left arm negative; left leg positive

• Central terminal – At intersection of leads I, II, and III


The Twelve Lead ECG

• Limb leads include leads I, II and III, and AVR, AVL, and AVF

• Einthoven’s triangle consists only of leads I, II, and III


The Twelve Lead ECG

• Leads I, II, and III are called standard leads or bipolar leads– These show the difference in electrical

potential between two limb electrodes


The Twelve Lead ECG

• Central terminal is negative; limb electrodes are positive

• Lead II and right chest leads identify cardiac problems– They best show the P wave


The Twelve Lead ECG

• P wave– To identify a dysrhythmia, or abnormal heart

rhythm (also referred to as “arrhythmia”)

• Remember to treat the patient, not the monitor!


Apical Radial Pulse Rate

• Apical-radial pulse rate– Comparison of apical and radial pulse; usually

they are the same

• Difference between apical and radial pulse is pulse deficit

• Pulse deficits are present in some forms of heart disease


Pulses in Legs and Feet

• Femoral pulse– Center of crease in leg near groin

• Posterior tibial pulse– Posterior to inner ankle


Pulses in Legs and Feet

• Dorsalis pedis artery– Imaginary line drawn from the ankle to

between the great toe and second toe

• Count the pulse for one full minute


Other Measurements

• If peripheral pulse is weak or irregular, check the apical pulse

• Use Doppler to amplify pulse


Other Measurements

• Hypotension– Blood pressure below 100/60

• Prehypertension– 120/80 to 139/89 (likely to develop high blood

pressure)

• Hypertension– Blood pressure over 140/90


Infection Control

• Blood pressure cuffs– Potential source of infection

• Some facilities issue a disposable cuff to each patient


Infection Control

• Others require personnel to wipe the cuff with a disinfectant solution after each patient

• Follow your facility policies for prevention of infection


Cardiac Catheterization

• Diagnostic procedure that requires threading a catheter into the heart

• Complications – Nausea, vomiting– Low blood pressure– Bradycardia


Cardiac Catheterization

• Complications – Internal bleeding in which the patient may

complain of thigh, back, or groin pain– Hematoma formation at the puncture site– Myocardial infarction


Angiogram or Arteriogram

• Angiogram or arteriogram– X‑ray study of the blood vessels

• Specific vessels are studied by positioning a catheter into the artery


Angiogram or Arteriogram

• Contrast medium– Special dye injected through catheter during

x-ray– Enables physician to see blood vessels and

identify potential problems


Post-Arteriogram (Angiogram) Care

• Maintain bedrest for 4 to 6 hours

• Keep the head flat for 3 hours– Keep operative extremity extended

• Evaluate vital signs and peripheral pulses– Every 15 minutes x 4 – Every 30 minutes x 4 – Hourly until discharged


Post-Arteriogram (Angiogram) Care

• Monitor puncture site for bleeding and hematoma

• Encourage fluids and monitor I&O

• Verify patient has voided prior to discharge

• Inform RN if patient develops complications

chapter 16 cardiac care skills. copyright © 2007 thomson delmar learning. all rights reserved.2...

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lead ecg lead

minute slide

body slide

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p wave slide