1. Chapter 16
Cardiac Care Skills

2. Electrical Conduction of 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
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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
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4. 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
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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
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The Ventricles
Ventricles can function as the pacemaker at a rate of 20 to 40 beats per minute
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7. 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
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8. Monitoring the Heartbeat
QRS complex
Impulse traveling through the ventricles
T wave
Resting and recovery phase of the heart
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The Twelve Lead ECG
Lead I
Right arm negative; left arm positive
Lead II
Left leg positive; right leg negative
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The Twelve Lead ECG
Lead III
Left arm negative; left leg positive
Central terminal
At intersection of leads I, II, and III
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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
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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
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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
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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!
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15. 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
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Pulses in Legs and Feet
Femoral pulse
Center of crease in leg near groin
Posterior tibial pulse
Posterior to inner ankle
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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
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Other Measurements
If peripheral pulse is weak or irregular, check the apical pulse
Use Doppler to amplify pulse
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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
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Infection Control
Blood pressure cuffs
Potential source of infection
Some facilities issue a disposable cuff to each patient
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Infection Control
Others require personnel to wipe the cuff with a disinfectant solution after each patient
Follow your facility policies for prevention of infection
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22. Cardiac Catheterization
Diagnostic procedure that requires threading a catheter into the heart
Complications
Nausea, vomiting
Low blood pressure
Bradycardia
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23. 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
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24. Angiogram or Arteriogram
X‑ray study of the blood vessels
Specific vessels are studied by positioning a catheter into the artery
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25. Angiogram or Arteriogram
Contrast medium
Special dye injected through catheter during x-ray
Enables physician to see blood vessels and identify potential problems
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26. 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
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27. 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
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