1. Adult Health Nursing 1 :
Cardiac disorders 1
Fakeeh College for Medical Sciences
Fourth Year – Level 4
2020-2021, Semester II
Dr Imad AL-Jarrah, PhD,
RN
2. 2
Objectives:
o Compare the components of the normal ECG
with physiologic events of the heart.
o Define ECG as a waveform that represents the
cardiac electrical event in relation to the lead
depicted (placement of electrodes).
o Analyze elements of an ECG rhythm strip:
ventricular and atrial rate, ventricular and
atrial rhythm, QRS complex and shape, QRS
duration, P wave and shape, PR interval, and
PQRS ratio.
Assessment of Cardiovascular
Function
3. 3
Anatomy and Physiology
• The heart compose of three layers
– Endocardium: the inner layer of endothelial tissue
– Myocardium: the middle layer of the muscle fiber
responsible for pumping action
– Epicardium: the outer layer
4. 4
Anatomy and Physiology
• Right heart consists of Rt atrium, Rt ventricle,
distribute deoxygenated blood.
• Left heart consists of Lt atrium, Lt ventricle ,
distribute oxygenated blood.
• Varying thickness of a trial and ventricular wall
and left and right ventricles related to workload.
7. 7
Anatomy and Physiology
• The heart has large metabolic requirement, 70-
80% of delivered oxygen
• Coronary arteries are perfused during diastole
• Left coronary artery branches (LAD & LCX)
• Right coronary artery branch (RCA)
• Posterior wall received blood by (PDCA)
• Blood return to heart through the coronary sinus
Located in the Right atrium
9. 9
Cardiac Conduction
• Cardiac electrical cell is characterized by
– Atomicity: ability to initiate electrical
impulses
– Excitability: ability to respond to impulses
– Conductivity: ability to transmit
impulses
– Conductive System:(SA node – AV node –
bundle of His–Purkinje Fibers).
10. Components of the Conduction System
• Sinoatrial Node (Part I):
• located in back wall of the right atrium near the
entrance of vena cava
• initiates impulses 60-100 times per minute
without any nerve stimulation from brain
• establishes basic rhythm of the heartbeat
• called the pacemaker of the heart
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11. Components of the Conduction System
• Atrioventricular Node (Part II):
• located in the bottom of the right atrium near the
septum
• cells in the AV node conduct impulses more
slowly, so there is a delay as impulses travel
through the node
• initiates impulses 40-60 times per minute without
any nerve stimulation from brain
11
12. Components of the Conduction System
• Atrioventricular Bundle (Part III):
• These branch a lot to form the Purkinje fibers that transmit
the impulses to the myocardium
• The bundle of His, bundle branches and Purkinje fibers
transmit quickly and cause both ventricles to contract at
the same time (Like a “phone tree”)
12
13. 1 - Sinoatrial node (SA node)
2 - Atrioventricular node (AV node)
3 – Bundle of His
4 - Right & Left Bundle Branches
which lead to Purkinje Fibers
14. ELECTROCARDIOGRAM (ECG)
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The Electrical Basis of the EKG/ECG
o Electrical impulses are present on the skin surface at a very low
voltage; The EKG machine picks up these impulses and amplifies
them.
o Electrical activity is sensed by Electrodes are placed on the skin
surface to pick up these impulses and give us a picture of how they
are traveling in the form of an Electrocardiogram. This is printed on
EKG paper and is called a Rhythm strip or an EKG strip
15. Electrocardiogram (ECG)
15
Electrocardiogram Leads
o Electrode: an adhesive pad that
contains conductive gel and
attaches to patient’s skin
o Leads: the lead wires connect the
electrodes to the cardiac monitor
18. 18
How We Measure: ECG Paper
o EKG paper is divided into small
squares and larger squares
o Large squares are defined by a dark
line. They are 5 squares high and 5
squares long (0.20 seconds)
o Small squares may be lines or may be
dots within the dark lines. They are
0.04 seconds
19. 19
How We Measure: ECG Paper
Count the # of beats by 10’s (10-20-30-40…)
On a 6 second strip
HR for example above = 80 bpm
20. 20
Cardiac homodynamic
– Cardiac Out put: the amount of blood your heart
pumps each minute.
– cardiac output in terms of the following equation:
Cardiac output = stroke volume × heart rate.
– Values for cardiac output are usually denoted as L/min. For a
healthy person weighing 70 kg, the cardiac output at rest
averages about 5 L/min; assuming a heart rate of 70 beats/min,
the stroke volume would be approximately 70 ml.
21. 21
Cardiac homodynamic
– STROKE VOLUME : the amount of blood
ejected by Lt ventricle in each beat which is 70
ml determined by
•Preload
•After load
•Contractility
– EJECTION FRACTION: 42% for right heart and
50% for the left heart
22. Four determinants of cardiac output
22
Four determinants of cardiac output
Four determinants of cardiac output
23. Four determinants of cardiac output
• Heart rate: the faster the heart beats, the more blood can be pumped over a
particular period of time.
• Contractility: This can be equated to an increased contractility of the heart
muscle, resulting in increased cardiac output. Too little pedal power, or
impaired contractility, will reduce cardiac output.
• Preload: Is the stretch of myocardium or end-diastolic volume of the
ventricles and most frequently refers to the volume in a ventricle just before
the Contraction (start of systole)
• Afterload: Is the force against which the ventricles must act in order
to eject blood, and is largely dependent on the arterial blood
pressure and vascular tone.
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24. 24
ASSESSMENT
• Health history and clinical
manifestations
–Acute symptoms: current medication,
allergies, general appearance, hemodynamic status
–Stable patients: complete history, spouse or
partner, demographic information
25. 25
ASSESSMENT
• Cardiac S&S
–Chest pain or pressure
–Shortness of breath
–Edema and weight gain
–Palpitations
–Fatigue
–Dizziness or loss of consciousness
26. 26
PHYSICAL ASSESSMENT
• Blood pressure
– Normal is 120/80 mmhg ( 100/60 – 140/90 ) invasive
and non invasive
• Pulse pressure:
– Difference between systolic and diastolic, 30-40 mmhg,
reflects strock volume & ejection velocity, vascular
resistance,
– Less than 30 mmhg = serious reduction in output
28. 28
RISK FACTORS
– Nonmodifiable: age, positive family history,
race & gender
– Modifiable: hyperglycemia, hyperlipidemia,
hypertension, inactivity, smoking, obesity &
type A personality
29. 29
Laboratory tests
– Cardiac enzymes
• Iso enzymes are more specific, createnine
kinase ( CK ) and its iso enzyme ( CK-MB ),
lactic dehydrogenase (LDH) ,troponin I
30. 30
Laboratory tests
– Blood chemistry
•Lipid profile:
A- Cholesterol (less than 200 mg/dl),
B- Triglycerides ( 40 – 150 mg / dl ) source of
energy, cell wall, store in a depose tissue.
C- LDL ( less than 130 mg / dl )
D- HDL (35 – 65 mg/dl M, 35 – 85 mg/dl F)
31. 31
Laboratory tests
• Serum electrolytes
– K, Na, Ca and other electrolytes can reflect the heart
function as well as fluid & electrolyte disturbances
• BUN
– May indicates impaired renal function and impaired
cardiac output
32. 32
Laboratory tests
• Coagulation studies
– Partial Thromboplastine Time (PTT): 25 – 40
sec, used to regulate heparin dosage,1.5–2.5 is
the therapeutic range
– Prothrombin Time (PT): less than13 sec, used
to regulate warfarin, 1.5 – 2.5 times of PT is the
therapeutic range
– International Normalized Ratio (INR):
standardized method for reporting PT level,
used for regulating warfarin dosage
33. 33
Diagnostic Evaluation
• Chest X-Ray ( CXR ) fluoroscopy
– Assess size, position of the heart, cardiothoracic ratio (
CTR ), position of central lines
• Electrocardiography (ECG)
– Can be either on bed side or from a distance, 12 leads
ECG, continuous monitoring, telemetry monitoring 2 or
3 leads monitoring)
34. 34
Diagnostic Evaluation
• Cardiac Stress Test
During time of increased demand, abnormalities
in cardiovascular functions are more likely to
be detected, used to evaluate the heart
function, coronary arteries as well as the cause
of chest pain
35. 35
Diagnostic Evaluation
–Exercise stress test: pt walk on a treadmill
or pedals (stationary bicycle), the goal is to increase HR
and monitored for ECH changes, arrhythmias,
hypotension, pain, dyspnea and dizziness. Pt fast 4
hours before test, nurse needs to instruct pt about the
test
36. 36
• Cardiac catheterization
– Invasive diagnostic procedure involves
introduction of specific catheter into Rt & Lt side
blood vessels under fluoroscopy. Its used to
evaluate coronary arteries potency, heart
function as a pump, vascular system and heart
structure
