Download Intermediate Cardiology

New Hampshire
EMT-Intermediate
Cardiology
New Hampshire
Division of Fire Standards & Training and
Emergency Medical Services
Objectives

Describe the incidence, morbidity, and
mortality of cardiovascular disease.

Discuss prevention strategies that may reduce
morbidity and mortality of cardiovascular
disease.

Identify the risk factors most predisposing to
coronary artery disease.
Objectives

Describe the anatomy of the heart, including the
position in the thoracic cavity, layers of the hear
chambers, and location and function of cardiac
valves.

Identify the major structures of the vascular
system.

Describe the distribution of the coronary arteries
and the parts of the heart supplied by each
artery.

Differentiate the structural and functional aspects
of arterial and venous blood vessels.
Objectives continued
Define the following terms that refer to cardiac
physiology:
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Stroke volume
Starling’s Law
Preload
Afterload
Cardiac output
Blood pressure

Describe the electrical properties of the heart.

Describe the normal sequence of electrical
conduction through the heart and state the
purpose of this conduction system.
Objectives continued
Describe the location and function of the
following structures of the electrical conduction
system: (C-1)
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SA node
Internodal and interatrial tracts
AV node
Bundle of His
Bundle branches
Purkinje fibers

Define cardiac depolarization and repolarization
and describe the major electrolyte changes that
occur in each process. (C-1)

Describe an ECG. (C-1)
Explain the purpose of ECG monitoring and its
limitations. (C-1)

Objectives continued
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Define the following terms as they relate to the electrical
activity of the heart:

Isoelectric line

QRS complex

P wave
State the numerical values assigned to each small and
each large box on the ECG graph paper for each axis.
Define ECG artifact and name the causes.

Correlate the electrophysiological and hemodynamic
events occurring throughout the entire cardiac cycle with
the various ECG wave forms, segments and intervals.

Relate the cardiac surfaces or areas represented by the
ECG leads .

Given an ECG, identify the arrhythmia.

Describe a systematic approach to analysis and
interpretation of cardiac dysrhythmias.
Objectives continued
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Describe the dysrhythmias originating in the sinus node and
the ventricles.
Describe the process and pitfalls of differentiating wide QRS
complex tachycardias.
Describe the term “cardiac arrest”.
Describe the arrhythmias seen in cardiac arrest.
Identify the critical actions necessary in caring for the
patient with cardiac arrest.
Explain how to confirm asystole using the 3-lead ECG.
List the clinical indications for defibrillation.
Describe the most commonly used pharmacological agents
in the management of cardiac arrest for EMT-Intermediates.
Identify resuscitation.
Identify circumstances and situations where resuscitation
efforts would not be initiated.
Identify local protocol dictating circumstances and
situations where resuscitation efforts would be
discontinued.
Objectives continued
Integrate the pathophysiology principles to the assessment
of the patient with cardiac arrest.
Synthesize assessment findings to formulate a rapid
intervention for a patient in cardiac arrest.
Describe the conditions of pulseless electrical activity.
Value and defend the urgency in rapid determination of and
rapid intervention of patients in cardiac arrest.
Identify the location of the structures listed in cognitive
objective #2.
Demonstrate how to set and adjust the ECG monitor
settings to varying patient situations.
Demonstrate a working knowledge of various ECG lead
systems
Demonstrate satisfactory performance of psychomotor skills
of basic and advanced life support techniques according to
the current American Heart Association standards and
guidelines, including:
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Cardiopulmonary resuscitation
Defibrillation
Demonstrate how to record an ECG
Incidence

Prevalence of cardiac death outside of a hospital

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Prevalence of warning signs and symptoms for
cardiac emergencies

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Supportive statistics
Supportive statistics
Increased recognition of need for early
reperfusion
Morbidity/ mortality
Reduced with early recognition
 Reduced with early access to EMS system

Risk factors
Age
 Family history
 Hypertension
 Lipids
 Male sex
 Smoking
 Carbohydrate intolerance

Possible contributing risks
Diet
 Female sex
 Obesity
 Oral contraceptives
 Sedentary living
 Personality type
 Psychosocial tensions

Prevention Strategies
Early recognition
 Education
 Alteration of life style

Anatomy of the Heart
Anatomy of the heart
Tissue Layers

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Pericardium: protective sac surrounding
the heart. Two layers.
Myocardium: middle layer of the heart,
unique muscle cells that have the ability to
conduct electrical impulses from one
muscle cell to another, thus allowing the
heart to contract
Endocardium: inner layer of heart,
bathed in blood
Tissue Layers
Pericardial Membrane
Chambers
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Atria: superior chambers that receive
incoming blood
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Right & Left
Ventricles: inferior chambers that pump
blood out of the heart
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Right & Left
Heart Valves
Tricupid Valve: right aterioventricular
valve; 3 cusps or leaflets
 Bicupid (Mitral) Valve: left
aterioventricular valve; 2 cusps or leaflets
 Pulmonic Valve: right semilunar valve
 Aortic Valve: left semilunar valve

Coronary Circulation

Left Coronary
Artery
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Anterior Descending
Artery
Circumflex Artery
Right Coronary
Artery
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Posterior Descending
Artery
Marginal Artery
Blood flow of the heart
Cardiac Cycle

Right and left Ventricles contract together

Pressure of contraction produces closure of AV valve and opens
aortic and pulmonic valves

Systole: Contraction phase, usually referring to ventricular contraction

Disatole: relaxation phase, usually referring to ventricles, much longer
than systole (.52 seconds versus .28 seconds)


As rate increases, length of diastole decreases with less reduction
in length of systole
Phase during which most coronary artery filling occurs (about
70%)
Vascular System

Arterial
System
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arteries
arterioles
capillaries
Venous
System
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venules
veins
Cardiac Physiology

To understand EKGs you must thoroughly
understand the pumping actions of the
cardiac cycle
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Diastole: relaxation phase

Systole: contraction phase
Cardiac Physiology

Stroke volume

Starling’s Law

Preload

Afterload

Cardiac Output

Blood Pressure
Electrical Properties of the Heart
Sinoatrial (SA) node
Internodal and interatrial tracts
Atrioventricular (AV) node
Bundle of His
Bundle branches
Purkinje fibers
Depolarization

Process by which muscle fibers are
stimulated to contract by the alteration of
the electrical charge of a cell.
Accomplished by changes in electrolyte
concentrations across the cell membrane.
Intrinsic Rates

Pacemaker cells capable of self initiated
depolarization

Found throughout conduction system
except AV node
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SA node: 60-100/minute intrinsic rate
AV Junction tissue: 40-60/minute intrinsic
rate
Ventricles (bundle branches & Purkinje
fibers): 20-40/minute intrinsic rate
Repolarization

Once cells have depolarized, the
electrolytes are pumped back to their
resting or polarized state. This process is
called repolarization.
Autonomic nervous system relationship
to Cardiovascular system
Medulla
Carotid sinus and baroreceptor
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Location
Significance
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Parasympathetic system
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Sympathetic
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Alpha-vasoconstriction
Beta
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Inotropic
Dromotropic
Chronotropic
ECG Monitoring
EGC Monitoring
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Electrical activity of the heart

Does NOT indicate mechanical activity of
the heart.
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Must take a pulse.
ECG Components
Relationship of ECG to the heart
Dysrhythmias are the most common complication
within the first few hours of chest pain

Life-threatening – usually ventricular
fibrillation
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Non-life-threatening – may require prehospital intervention

Warning dysrhythmias – may be
forerunners of life-threatening
dysrhythmias and require pre-hospital
intervention
Basic concepts of ECG monitoring

ECG is graphic display of heart’s electrical
activity

Body acts as a giant conductor of
electrical current

ECG obtained by applying electrodes on
body surface which detect changes in
voltage of cells between sites of the
electrodes
Basic concepts of ECG monitoring

Voltage may be positive (upward deflection) or
negative (downward deflection)

These changes are input to ECG machine,
amplified and displayed visually on a scope
and/or graphically on ECG paper

Recorded as a continuous curve of waves and
deflections called the electrocardiogram (ECG)
Monitoring lead: any lead that shows very
clear wave forms, very often, lead II
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Information that can be gained from a
monitoring lead or rhythm strip:

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How fast the heart is beating
How regular the heartbeat is
ECG Graph Paper
Artifact

Deflections on the ECG display produced by
factors other than the heart’s electrical activity
such as:
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Standardization (calibration) marks
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Muscle tremors/shivering
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Patient or vehicle movement
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Loose electrodes
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60-cycle interference
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Machine malfunction
Steps to rhythm interpretation
1. Estimate Heart Rate
 2. Is the rhythm regular?
 3. Are there P waves?
 4. Is the QRS wide or narrow?
 5. Is there a relationship between P
waves and QRS complexes?
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1. Estimate Heart Rate
1. Estimate Heart Rate
Is the atrial rate the same as the ventricular?
Using the 300 rule, what is the rate?
What is the rate?
2. Is the rhythm regular?
Is it regular?
Is it irregular?
2. Is the rhythm regular?
Is it regular?
Is it irregular?
2. Is the rhythm regular?
Is it regular?
Is it irregular?
Are there any ectopic
beats?
3. Are there P waves?
Are the P waves regular?
What is the morphology? (upright
rounded and uniform)
Do all the P waves look alike?
3. Are there P Waves?
Are the P waves regular?
Is there one P wave for every
QRS?
What is the morphology?
(upright, rounded and uniform)
Are there more P waves
then QRSs?
Do all the P waves look
alike?
3. Are there P Waves?
Are the P waves regular?
Is there one P wave for every
QRS?
What is the morphology?
(upright, rounded and uniform)
Are there more P waves
then QRSs?
Do all the P waves look
alike?
3. Are there P waves?
Are the P waves regular?
Is there one P wave for every
QRS?
What is the morphology?
(upright, rounded and uniform)
Are there more P waves
then QRSs?
Do all the P waves look
alike?
4. Is the QRS wide or narrow?
Normal range < 0.12
4. Is the QRS wide or narrow?
Normal range < 0.12
5. Is there a relationship between P
waves and QRS complexes?
Normal PR interval = 0.12 – 0.20
Are all the PR
intervals’ constant?
Is the PR interval
measurement within
normal limits?
If the PR interval
varies, is there a
pattern to the change
in measurements?
5. Is there a relationship between P
waves and QRS complexes?
Normal PR interval = 0.12 – 0.20
Are all the PR
intervals’ constant?
Is the PR interval
measurement within
normal limits?
If the PR interval
varies, is there a
pattern to the change
in measurements?
Ectopic Beat (Complex)
•1. Estimate Heart Rate
•2. Is the rhythm regular?
•3. Are there P waves?
•4. Is the QRS wide or narrow?
•5. Is there a relationship between P waves and
QRS complexes?
•1. Estimate Heart Rate
•2. Is the rhythm regular?
•3. Are there P waves?
•4. Is the QRS wide or narrow?
•5. Is there a relationship between P waves and
QRS complexes?
•1. Estimate Heart Rate
•2. Is the rhythm regular?
•3. Are there P waves?
•4. Is the QRS wide or narrow?
•5. Is there a relationship between P waves and
QRS complexes?
•1. Estimate Heart Rate
•2. Is the rhythm regular?
•3. Are there P waves?
•4. Is the QRS wide or narrow?
•5. Is there a relationship between P waves and
QRS complexes?
Rhythms of the SA Node
 Sinus
Rhythm
 Sinus
Bradycardia
 Sinus
Tachycardia
 Sinus
Arrhythmia
Sinus Rhythm
1.
Rate: 60 - 100/minute
2. Is the rhythm regular or irregular?
Regular
3. Are there P waves? Yes
PR Interval: 0.12 - .0.20 seconds
4. Is the QRS wide or narrow? Narrow
5. Is there a relationship between P waves
and QRS complexes? Yes 1:1 ratio
Normal Sinus Rhythm
Sinus Bradycardia
1.
Rate: < 60/minute
2. Is the rhythm regular or irregular? Regular
3. Are there P waves? Yes
PR Interval: normal to slightly prolonged
4. Is the QRS wide or narrow? Narrow
5. Is there a relationship between P waves
and QRS complexes? Yes 1:1 ratio
Sinus Tachycardia
1. Rate: > 100/minute
2. Is the rhythm regular or
irregular? Regular
3. Are there P waves? Yes
PR Interval: normal to slightly
shortened
4. Is the QRS wide or narrow?
Narrow
5. Is there a relationship between P
waves and QRS complexes? Yes
1:1 ratio
Sinus Arrhythmia
1. Rate: 60 - 100/minute
2. Is the rhythm regular or irregular? Irregular
3. Are there P waves? Yes
PR Interval: Normal
4. Is the QRS wide or narrow? Narrow
5. Is there a relationship between P waves and QRS
complexes? Yes 1:1
Ventricular Rhythms
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Idioventricular rhythm
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Accelerated idioventricular rhythm
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Premature ventricular complex (ventricular
ectopic)
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Ventricular tachycardia
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Ventricular Fibrillation
Idioventricular Rhythm
1. Rate: 20 - 40/minute
2. Is the rhythm regular or irregular?
regular
3. Are there P waves? No
PR Interval:None
4. Is the QRS wide or narrow? Wide
5. Is there a relationship between P waves and
QRS complexes? No P Waves
Accelerated Idioventricular Rhythm
1. Rate: 40 - 100/minute
2. Is the rhythm regular or irregular? regular
3. Are there P waves? No
PR Interval: none
4. Is the QRS wide or narrow? Wide
5. Is there a relationship between P waves and
QRS complexes? No P waves
Premature Ventricular Complex (PVC)
1. Rate: depends on underlying rhythm
2. Is the rhythm regular or irregular? Irregular
3. Are there P waves? None in the PVC
PR Interval: None
4. Is the QRS wide or narrow? Wide; bizarre appearance
5. Is there a relationship between P waves and QRS
complexes? None in PVC
Ventricular Tachycardia
1. Rate: 100 - 250/minute
2. Is the rhythm regular or irregular? regular
3. Are there P waves? None or dissociated
PR Interval: None
4. Is the QRS wide or narrow? Wide; bizarre
appearance
5. Is there a relationship between P waves and QRS
complexes? No
Ventricular Tachycardia
Ventricular Tachycardia
Ventricular Fibrillation
1. Rate: Indeterminate
2. Is the rhythm regular or irregular? Chaotic
3. Are there P waves? None
PR Interval: None
4. Is the QRS wide or narrow? None
5. Is there a relationship between P waves and QRS complexes?
No P waves, no QRS complexes
Ventricular Fibrillation
Ventricular Fibrillation
Asystole
1
. Rate: Indeterminate
2. Is the rhythm regular or irregular? No rhythm
3. Are there P waves? None
PR Interval: None
4. Is the QRS wide or narrow? None
5. Is there a relationship between P waves and
QRS complexes? No P waves, no QRS
complexes
Asystole
Check your patient. (apneic/pulseless)
Check your leads.
Check Connections to monitor.
Check more then one lead.
What are these rhythms?
What are these rhythms?
Asystole
P.E.A.
Pulseless Electrical Activity
 There is electrical activity on the monitor,
but there is no pulse
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The Hs & Ts
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Hypovolemia
Hypoxia
Hypothermia
Hydrogen Ions
(acidosis)
Hypo/hyperkalemia
Hypoglycemia
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Tamponade
Tension Pneumo
Thrombosis,
pulmonary
(embolism)
Thrombosis,
coronary (ACS)
Toxins (OD)
Trauma
(hypovolemia)
Reversible causes for Hs

Hypovolemia = give them fluid
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Hypoxia = oxygenate and ventilate
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Hypothermia = warming

Hydrogen Ions = can be treated by the
paramedic with sodium bicarbonate

Hypo/hyperkalemia: hyperkalemia can be
treated by the paramedic with sodium
bicarbonate

Hypoglycemia = D50
Reversible causes for Ts

Tamponade: Pericardiocentesis

Tension Pneumo: Needle decompression

Thrombosis, pulmonary (emboli): Surgery,
thrombolytics

Thrombosis, coronary (ACS): Thrombolytics

Toxins (OD): Depends what agent overdoses on.
Narcan.

Trauma: fluids

Many treatments are done by paramedics or physician, early
recognition of PEA and early paramedic intercept can be life
saving
QUESTIONS?
Special Thank You to:

Christopher Rousseau, NREMT-I