Download Cardiac Monitoring Atrial Fibrillation

Coronary Artery Disease
Complications
Cardiac
Arrhythmias/Dysrhythmias
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Conduction System
Four Properties of Cardiac Tissue
 Automaticity
– ability to initiate an impulse
 Contractility – ability to respond
mechanically to an impulse
 Conductivity – ability to transmit an impulse
along a membrane in an orderly manner
 Excitability – ability to be electrically
stimulated
Cardiac Conduction
System
Specialized neuromuscular tissue
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PR Interval:
SA Node – upper R atrium through Bachman’s
Bundle
AV Node – internodal pathway
Bundle of His
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QRS Complex:
Right and Left Bundle Branches
Purkinje Fibers
Cardiac Conduction
Cardiac Monitoring
PQRS Complex
Cardiac Action Potential
Calculating Heart Rate
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EKG paper is a grid where time is measured along the horizontal axis.
Each small square is 1 mm in length and represents 0.04 seconds.
Each larger square is 5 mm in length and represents 0.2 seconds.
Voltage is measured along the vertical axis - 10 mm is equal to 1mV in voltage.
Heart rate can be easily calculated from the EKG strip:
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Heart rate can be easily calculated from the EKG strip:
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When the rhythm is regular:
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the heart rate is 300 divided by the number of large squares between the QRS complexes.
e.g., if there are 4 large squares between regular QRS complexes, the heart rate is 75 (300/4=75).
The second method can be used with an irregular rhythm to estimate the rate:
• Count the number of R waves in a 6 second strip and multiply by 10.
• e.g., if there are 7 R waves in a 6 second strip, the heart rate is 70 (7x10=70).
Cardiac Monitoring
Cardiac Rate
Cardiac Monitoring
Amplitude / Duration
12 Lead EKG
EKG Leads
12-Lead EKG
Reciprocal EKG Changes
Cardiac Monitoring
Chest Lead Placement
Cardiac Monitoring- MCL
Cardiac Monitoring
Normal Sinus Rhythm
Cardiac Monitoring
PQRS Complex
Cardiac Monitoring
Cardiac Rhythm Analysis
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Analyze the P waves – rate/rhythm
Analyze the QRS complexes – rate/rhythm
Determine the heart rate
Measure the PR Interval
Measure the QRS duration
Interpret the rhythm
Clinical significance? Hemodynamic status?
Appropriate Tx
Cardiac Monitoring
Normal Sinus Rhythm
Cardiac Monitoring
Normal Sinus Rhythm
EKG / Heart Sounds
Cardiac Monitoring
Normal Sinus Rhythm
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Atrial & Ventricular rhythms: regular
Rate: 60-100 beats/min
P waves: present consistent
configuration, one P wave prior to
each QRS complex
PR interval: .12 – .20 sec and constant
QRS duration: -.04 to .10 sec and
constant
Cardiac Monitoring
Sinus Dysrhythmias
Cardiac Monitoring
Sinus Bradycardia
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SA Node discharges < 60 beats/ min
Etiology: >parasympathetic stimulation /
vagus nerve
Assess: LOC, Orientation, VS, PO, pain,
escaped ventricular ectopy
Tx: If patient is symptomatic – raise legs up,
move patient, Atropine – ACLS Bradycardia
Cardiac Monitoring
Sinus Tachycardia Sinus Bradycardia
Cardiac Monitoring
Sinus Tachycardia
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SA Node discharge > 100 beats/ min
Etiology: Sympathetic stimulation –
normal or abnormal response
Tx: Treat underlying cause
Cardiac Supply Problems
Cardiac Demand Problems
 E.g.,
hypovolemia, hypoxemia, anxiety, pain,
anemia, angina
Regular Narrow QRS - Adenosine
Sustained
Tachy / Brady Dysrhythmias
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Chest discomfort, or pain, radiation to jaw, back, shoulder or
upper arm
Restlessness, anxiety, nervousness
Dizziness, syncope
Change in pulse strength, rate, rhythm
Pulse deficit
Shortness of breath, dyspnea
Tachypnea, Orthopnea
Pulmonary rales
S3 or S4 heart sounds
Jugular vein distention
Weakness, fatigue
Pale, cool skin, diaphoresis
Nausea, vomiting
Decreased urine output
Hypotension
Cardiac Monitoring
PSVT
Cardiac Monitoring
Paroxysmal Supraventricular
Narrow QRS Tachycardia (PSVT)
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SA Node rate 100-280 beats/min - Mean 170 beats/min
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Etiology: Pre-excitation syndrome, e.g., WolffParkinson White (WPW) Syndrome
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Assess: Weakness, fatigue, chest pain, chest wall
pain, hypotension, dyspnea, nervousness
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Tx: Valsalva maneuvers: bearing down, gagging,
ocular pressure, vomiting, carotid sinus massage,
Meds: Adenosine
Cardiac Monitoring
Interference
Cardiac Monitoring
Atrial Flutter / Fibrillation
Cardiac Monitoring
Atrial Flutter / Fibrillation
Cardiac Monitoring
Atrial Fibrillation
Most Common dysrhythmia in the US
 Multiple rapid impulses from many atrial
foci, rate of 350-600/min—depolarize the
atrial in a disorganized and chaotic
manner – atrial quiver
 Results:
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No P waves
No atrial contracts
No atrial kick
Irregular ventricular response
Cardiac Monitoring
Atrial Fibrillation
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Etiology: MI, RHD with Mitral Stenosis,
CHF, COPD, Cardiomyopathy,
Hyperthyroidism, Pulmonary emboli, WPW
Syndrome, Congenital heart disease
** Mural Thrombi – increased risk for
pulmonary & systemic thromboemboli
to brain & periphery
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Assess: VS, PO, Pulse Deficit, chest pain,
syncope, hypotension
Symptoms worsen with increased ventricular
response
Cardiac Monitoring
Atrial Fibrillation
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Tx:
TEE – Trans-esophageal echocardiogram
 Identifies
thrombi on valves
Medications to decrease the ventricular
response - Metoprolol (Lopressor)
Oxygen
Prophylactic anticoagulation
 Lovenox
- Coumadin – long term
Cardioversion
Cardiac Monitoring
Atrial Fibrillation
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Tx:
Medications to decrease the ventricular response
 Narrow
QRS irreg rhythm–diltiazem; beta-blockers
 Wide QRS reg rhythm – amiodarone
 Wide QRS irreg rhythm – digoxin, diltiazem, verapermil,
amiodarone
Oxygen
Prophylactic anticoagulation
Cardioversion
Cardiac Monitoring
Atrial Fibrillation
Cardioversion
Synchronized countershock
 50
– 100 Joules
 Avoids delivering shock during repolarization
 Patent intravenous line
 Patient sedated – Versed
 Oxygenation
 ABC
 Assess: VS, PO, Monitor cardiac rate - rhythm
 Administer antidysrhythmic medication
Cardiac Monitoring
Junctional Escape Rhythm
Cardiac Monitoring
Junctional Escape Rhythm
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Impulse generated from AV nodal cells
at the AV Junction
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Escape pacemaker
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Rate 40-60 beats/ min
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Transient
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Assess: Patient hemodynamic stability
Cardiac Monitoring
Premature Ventricular
Contractions
Cardiac Monitoring
NSR – V. Tach – V. Fibrillation
Cardiac Monitoring
Ventricular Tachycardia
Cardiac Monitoring
Ventricular Dysrhythmias
Cardiac Monitoring
Premature Ventricular
Contractions
Cardiac Monitoring
Premature Ventricular
Contractions (PVCs)_
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Early ventricular complexes
Followed by compensatory pause
Fit between two NSR beats - interpolated
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Unifocal, multifocal, couplet, triplets,
bigeminy, trigeminy, quadrigeminy
 3+ = ventricular tachycardia
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Etiology: myocardial ischemia, <K+, CHF,
metabolic acidosis, airway obstruction
Cardiac Monitoring
Premature Ventricular
Contractions (PVCs/
Ventricular Tachycardia
with Pulse
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Assess: LOC, hemodynamic status-continuous cardiac monitoring of
rhythm & rate, VS, PO, peripheral
perfusion
Tx: Underlying cause + Oxygen,
Amiodarone IV bolus / Infusion
V. Tachycardia/V. Fibrillation
Pulseless
 TX: CPR BLS - Airway, Breathing, Circulation
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Shockable Rhythm VT/VF: Defibrillate – 120-200 Joules
 CPR x 5 cycles
Check rhythm – shockable?
Defibrillate (biphasic 200 J / monophasic 360 J
 Resume CPR
Epinephine 1 mg IV (repeat q3-5 mins) / Vasopressin
 CPR x 5 cycles
Check rhythm – shockable?
Defibrillate (biphasic 200 J / monophasic 360 J
 Resume CPR
 Antiarrhythmics: amiodarone/lidocaine
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Magnesium – torsades de pointes
Cardiac Monitoring
V Fib - Agonal Rhythm
Common Causes of
Dysrhythmias
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Cardiac
Accessory pathways, conduction defects,
congestive heart failure, left ventricular
hypertrophy, myocardial cell degeneration,
myocardial infarction
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Other Conditions
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Acid-base imbalances, alcohol, coffee, tea, tobacco,
connective tissue disorders, drug effects or toxicity,
electric shock, electrolyte imbalances, emotional crisis,
hypoxia, shock, metabolic disorders (e.g. thyroid),
near-drowning, poisoning
Cardiac Monitoring
Heart Block
1st, 2nd Types I & II
Cardiac Monitoring
Heart Blocks
Cardiac Monitoring
First Degree AV Block
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First Degree AV Block: all sinus impulses
eventually reach ventricles
Prolonged PR Interval >.20
Etiology: AV nodal ischemia – right coronary
artery (inferior MI); hypokalemia, increased
beta-blockers or calcium channel blockers,
narcotics, excessive vagal stimulation
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Assess: Hemodynamically stable
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Tx: withhold offending medication; oxygen;
atropine, notify physician; observe
Cardiac Monitoring
Second Degree AV Block
Mobitz Type I - Wenckebach
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Each impulse takes progressively longer
 Progressive lengthening of PR Interval
 Followed by a dropped beat (missing QRS complex) & a pause
 May need temporary transvenous pacer
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Etiology: Often transient following anterior / inferior wall
MI – may revert to 1st Degree AV Block
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Assess: Hemodynamic stability
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Tx: Atropine / May require Temporary Transcutaneous
Pacemaker / CPR / ACLS Protocol
Cardiac Monitoring
Second Degree AV Block Mobitz
Type I - Wenckebach
Cardiac Monitoring
Second Degree AV Block
Mobitz Type II
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Etiology: Infranodal block in one of the bundle
branches
 Dropped QRS complex without progressive lengthening of
PR interval
 P wave with no QRS complex following
 Random block
 May progress to 3rd Degree AV Block – need for
permanent pacer
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Assess: Hemodynamic stability
Tx: Atropine / Transcutaneous pacemaker / CPR /
ACLS Protocol
Cardiac Monitoring
Third Degree AV Block
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No sinus impulses conduct to the ventricles
AV dissociation – rate: 40/min
PR interval not constant – no relationship with P and
QRS complex
Ventricular pacemaker – may abruptly fail causing
ventricular asystole
Etiology: Anterior Wall MI; hypoxemia, electrolyte
disturbances, cardiac surgery
Cardiac Monitoring
Third Degree AV Block
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Assess: Hemodynamic stability
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Tx:
 CPR
 ACLS Protocol
 Pacemaker
Cardiac Monitoring
Paced Rhythm
Cardiac Monitoring
Paced Rhythm
Indications for
Permanent Pacemaker
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Chronic atrial fibrillation with slow ventricular
response
Fibrosis or sclerotic changes of the cardiac
conduction system
Hypersensitive carotid sinus syndrome
Sick sinus syndrome
Sinus node dysfunction
Tachydysrhythmias
Third-degree AV block
Cardiac Monitoring
Ventricular Standstill
Pulseless Asystole
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CPR
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ACLS Protocol
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Tx: Atropine, Epinephrine, dopamine
Pulseless Asystole
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Shockable Rhythm? No – BLS/CPR
Epinephrine 1 mg IV (may repeat q3-5 mins)
(or one dose of Vasopressin)
Atropine
5 cycles of CPR
Shockable rhythm? NO - CPR
Yes – Pulseless V Fib
Cardiac Dysrhythmias
ASSESS THE PATIENT
Treat the underlying cause
Support hemodynamically
Emergency Cardiac Medication
CPR
Transcutaneous/Transvenous pacemaker
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Information and emotional support to
patient & family
New Cardiac Advances
Implantable cardioverter – defibrillator
(AICD)
 Automatic external defibrillator (AED)
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ABCD
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Cardiac Ablation Therapy
BLS
 ACLS
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