dysrhythmia and conduction problems-1
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Chapter 27
Management of Patients With Dysrhythmias and
Conduction Problems
Chapter 27
Management of Patients With Dysrhythmias and
Conduction Problems
Christie M. Candelaria, MA, RN, CCRN
Learning Outcomes/Objectives:Learning Outcomes/Objectives:• Identify clinical characteristics and ECG patterns of
normal sinus rhythm and common dysrhythmias as follows:
– sinus bradycardia
– sinus tachycardia
– atrial fibrillation
– atrial flutter
– ventricular tachycardia
– ventricular fibrillation
• Describe the nursing and collaborative management of patients with common dysrhythmias mentioned above.
Cardiac conductionCardiac conduction
• SA Node
• AV node
• Bundle of HIS
• Right & Left
Bundle Branches
• Purkinje Fibers
http://www.youtube.com/watch?v=H04d3rJCLCE&feature=related
Cardiac CycleCardiac Cycle
Refers to the a repetitive pumping process that includes all of the events associated with blood flow through the heart
Depolarization- electrical stimulation
Systole—period during which ventricles mechanically contract and blood is being ejected
Repolarization – electrical relaxation
Diastole—period of mechanical relaxation in which ventricles are filling
EKG PaperEKG Paper
EKG Paper EKG Paper
Components of EKG WaveformComponents of EKG Waveform
P WAVE
• Indicates atrial depolarization, contraction of the atrium
• Normal duration is not longer than 0.11 seconds (less than 3 small squares)
• Amplitude (height) is no more than 3 mm
• Normally no notching or peaking
Components of EKG WaveformsComponents of EKG Waveforms
PR Interval
• Indicates AV conduction time
• Duration time is 0.12 to 0.20 seconds
Components of EKG WaveformComponents of EKG Waveform
QRS Complex• Indicates ventricular depolarization, or contraction of the
ventricles
• Shortly after depolarization begins, the ventricles contract
• Normal duration is 0.08-0.12
QRS complexQRS complex
Q Wave– 1st downward deflection in the depolarization of the ventricle (many times may be absent)
QRS ComplexQRS Complex
R Wave– 1st upward deflection of the QRS (may follow a Q wave or be present by itself)
QRS complexQRS complex
ST Segment
• terminal portion of QRS, represents the delay time after depolarization and waiting for repolarization
• Normally not depressed more than 0.5mm
• May be elevated slightly in some leads (no more than 1 mm)
(this is EXTREMELY important in diagnosing MI)
Components of EKG WaveformComponents of EKG Waveform
T Wave (ahhh rest)
• Indicates ventricular repolarization
• Not more than 5mm in amplitude in standard leads and 10mm in precordial leads
• Rounded and asymmetrical
• Last 1/3 of vulnerable area of time—if a ventricular response is initiated here, such as a PVC, V-Tach can occur
• Also useful in diagnosing ischemia or MI
Components of EKG WaveformComponents of EKG Waveform
QT Interval
• Indicates repolarization time
• General Rule: duration is less than half the preceding R-R interval
• Will lengthen and shorten as the rate changes
U WaveU Wave
• Represents repolarization of His-Purkinje system
• Not present on every strip
• A prominent U wave may be due to hypercalcemia, hypokalemia, or digoxin toxicity
Putting it all together:Putting it all together:
DysrhythmiasDysrhythmias
• Disorders of formation or conduction (or both) of electrical impulses within heart
• Can cause disturbances of
– Rate
– Rhythm
– Both rate, rhythm
• Potentially can alter blood flow, cause hemodynamic changes
• Diagnosed by analysis of electrographic waveform
Tips for applying electrodesTips for applying electrodes
• Make sure skin is thoroughly dry.
• Clip chest hair.
• Remove any excess skin oil with alcohol.
• Apply tincture of benzoin if keeping electrodes is difficult.
• Connect each lead wire to a disc before applying it to the chest.
• Make sure the center of the electrode disc is moist.
• Avoid applying electrodes over these areas:
– Bony areas skin folds
– Scar tissue breast tissue
– Muscle mass (significant) heart apex
Assessment of Cardiac RhythmAssessment of Cardiac Rhythm
Copyright © 2007, 2004, 2000, Mosby, Inc., an affiliate of Elsevier Inc. All Rights Reserved.
Fig. 36-5
Assessment of Cardiac RhythmAssessment of Cardiac Rhythm
Copyright © 2007, 2004, 2000, Mosby, Inc., an affiliate of Elsevier Inc. All Rights Reserved.
Fig. 36-9
Assessment of Cardiac Rhythm Assessment of Cardiac Rhythm
Copyright © 2007, 2004, 2000, Mosby, Inc., an affiliate of Elsevier Inc. All Rights Reserved.
Heart Rate DeterminationHeart Rate Determination
Evaluation of DysrhythmiasEvaluation of Dysrhythmias
• Holter monitoring
• Event recorder monitoring
• Exercise treadmill testing
• Signal-averaged ECG
• Electrophysiologic study
Normal Sinus RhythmNormal Sinus Rhythm Originates in the sinoatrial node (SA)
Rhythm: atrial/ventricular regular
Rate: atrial/ventricular rates 60 to 100 bpm
P waves: present, consistent configuration
One P wave before each QRS
PR interval: 0.12 to 0.20 second and constant
QRS duration: 0.04 to 0.10 second and constant
Normal Sinus RhythmNormal Sinus Rhythm
• Sinus node fires 60 to 100 bpm
• Follows normal conduction pattern
Copyright © 2007, 2004, 2000, Mosby, Inc., an affiliate of Elsevier Inc. All Rights Reserved.
Fig. 36-8
Normal Sinus Rhythm Normal Sinus Rhythm
Sinus BradycardiaSinus Bradycardia
Sinus BradycardiaSinus Bradycardia
• Clinical associations
– Occurs in response to
•Carotid sinus massage
•Hypothermia
•Increased vagal tone
•Administration of parasympathomimetic drugs
Sinus BradycardiaSinus Bradycardia• Clinical associations
– Occurs in disease states
• Hypothyroidism
• Increased intracranial pressure
• Obstructive jaundice
• Inferior wall MI
Sinus BradycardiaSinus Bradycardia
•Clinical significance
– Dependent on symptoms• Hypotension
• Pale, cool skin
• Weakness
• Angina
• Dizziness or syncope
• Confusion or disorientation
• Shortness of breath
Sinus BradycardiaSinus Bradycardia
• Treatment
– Atropine
– Pacemaker may be required
PacemakersPacemakers
Copyright © 2007, 2004, 2000, Mosby, Inc., an affiliate of Elsevier Inc. All Rights Reserved.
Fig. 36-27
PacemakersPacemakers
Fig. 36-25 Fig. 36-26
PacemakersPacemakers
Fig. 36-24 B
Copyright © 2007, 2004, 2000, Mosby, Inc., an affiliate of Elsevier Inc. All Rights Reserved.
Fig. 36-24 A
Pacer spikesPacer spikes
Sinus TachycardiaSinus Tachycardia
Tachycardia Tachycardia
Heart rate greater than 100 bpm
Shorten diastolic time = perfusion time
Initial CO and B/P
Ventricular filling = stroke volume = aortic pressure
Eventually = CO and B/P
Increases the work of the heart, increasing myocardial O2 demand
Sinus Tachycardiahttp://ems-ed.net/Video/ems-edbasicecg2.html
Sinus Tachycardiahttp://ems-ed.net/Video/ems-edbasicecg2.html
•Discharge rate from the sinus node is increased as a result of vagal inhibition and is >100 bpm
Copyright © 2007, 2004, 2000, Mosby, Inc., an affiliate of Elsevier Inc. All Rights Reserved.
Sinus TachycardiaSinus Tachycardia
• Clinical associations
– Associated with physiologic stressors
•Exercise
•Pain
•Hypovolemia
•Myocardial ischemia
•Heart failure (HF)
•Fever
Sinus TachycardiaSinus Tachycardia
• Clinical significance
– Dizziness and hypotension due to decreased CO
– Increased myocardial oxygen consumption may lead to angina
Sinus TachycardiaSinus Tachycardia
• Treatment
– Determined by underlying cause
-Adrenergic blockers to reduce HR and myocardial oxygen consumption
•Antipyretics to treat fever
•Analgesics to treat pain
Atrial FlutterAtrial Flutter
Atrial FlutterAtrial Flutter
• Clinical associations
– Usually occurs with
• CAD
• Hypertension
• Mitral valve disorders
• Pulmonary embolus
• Chronic lung disease
• Cardiomyopathy
• Hyperthyroidism
• Drugs: Digoxin, quinidine, epinephrine
Atrial FlutterAtrial Flutter
• Clinical significance
– High ventricular rates (>100) and loss of the atrial “kick” can decrease CO and precipitate HF, angina
– Risk for stroke due to risk of thrombus formation in the atria
Atrial FlutterAtrial Flutter
• Treatment
– Primary goal is to slow ventricular response by increasing AV block
• Drugs to slow HR: Calcium channel blockers, -adrenergic blockers
• Electrical cardioversion may be used to convert the atrial flutter to sinus rhythm emergently and electively
Atrial FlutterAtrial Flutter
• Treatment
– Primary goal is to slow ventricular response by increasing AV block
• Antidysrhythmia drugs to convert atrial flutter to sinus rhythm or to maintain sinus rhythm (e.g., amiodarone, propafenone)
• Radiofrequency catheter ablation can be curative therapy for atrial flutter
Atrial FibrillationAtrial Fibrillation
Atrial Fibrillation Atrial Fibrillation
• Clinical associations
– Usually occurs with
•Underlying heart disease, such as rheumatic heart disease, CAD
•Cardiomyopathy
•HF
•Pericarditis
Atrial Fibrillation Atrial Fibrillation
• Clinical associations
– Often acutely caused by
•Thyrotoxicosis
•Alcohol intoxication
•Caffeine use
•Electrolyte disturbance
•Cardiac surgery
Atrial Fibrillation Atrial Fibrillation
• Clinical significance
– Can result in decrease in CO due to ineffective atrial contractions (loss of atrial kick) and rapid ventricular response
– Thrombi may form in the atria as a result of blood stasis
– Embolus may develop and travel to the brain, causing a stroke
Atrial Fibrillation Atrial Fibrillation • Treatment
– Goals
•Decrease ventricular response
•Prevent embolic stroke– Drugs for rate control: digoxin, -
adrenergic blockers, calcium channel blockers
– Long-tern anticoagulation: Coumadin
Atrial Fibrillation Atrial Fibrillation • Treatment
– For some patients, conversion to sinus rhythm may be considered
•Antidysrhythmic drugs used for conversion: Amiodarone, propafenone
•cardioversion may be used to convert atrial fibrillation to normal sinus rhythm
Atrial Fibrillation Atrial Fibrillation
• Treatment
– If patient has been in atrial fibrillation for >48 hours, anticoagulation therapy with warfarin is recommended for 3 to 4 weeks before cardioversion and for 4 to 6 weeks after successful cardioversion
Atrial Fibrillation Atrial Fibrillation • Treatment
– Radiofrequency catheter ablation
– Maze procedure
– Modifications to the Maze procedure
•Use of cold (cryoablation)
•Use of heat (high-intensity ultrasound)
LETHAL DYSRHYTHMIASLETHAL DYSRHYTHMIAS
Ventricular TachycardiaVentricular Tachycardia
Ventricular FibrillationVentricular Fibrillation
AsystoleAsystole
Nursing Process: Care of the Patient with a Dysrhythmia - AssessmentNursing Process: Care of the Patient with a Dysrhythmia - Assessment
• Assess indicators of cardiac output and oxygenation, especially changes in level of consciousness
• Physical assessment include
– Rate, rhythm of apical, peripheral pulses
– Heart sounds
– Blood pressure, pulse pressure
– Signs of fluid retention
Nursing Process: Care of the Patient with a Dysrhythmia – Assessment (cont’d)Nursing Process: Care of the Patient with a Dysrhythmia – Assessment (cont’d)
• Health history: include presence of coexisting conditions, indications of previous occurrence
• Medications
Nursing Process: Care of the Patient with a Dysrhythmia - DiagnosesNursing Process: Care of the Patient with a Dysrhythmia - Diagnoses
• Decrease cardiac output
• Anxiety
• Deficient knowledge
Collaborative Problems/Potential ComplicationsCollaborative Problems/Potential Complications
• Cardiac arrest
• Heart failure
• Thromboembolic event, especially with atrial fibrillation
Nursing Process: Care of the Patient with a Dysrhythmia - PlanningNursing Process: Care of the Patient with a Dysrhythmia - Planning
• Goals
– Eradicating or decreasing occurrence of dysrhythmia to maintain cardiac output
– Minimizing anxiety
– Acquiring knowledge about dysrhythmia, its treatment
Decreased Cardiac OutputDecreased Cardiac Output
• Monitoring
– ECG monitoring
– Assessment of signs, symptoms
• Administration of medications, assessment of medication effects
• Adjunct therapy: cardioversion, defibrillation, pacemakers
Other InterventionsOther Interventions
• Anxiety
– Use calm, reassuring manner
– Measures to maximize patient control to make episodes less threatening
– Communication, teaching
• Teaching self-care
– Include family in teaching
Cardioversion and DefibrillationCardioversion and Defibrillation
• Treat tachydysrhythmias by delivering electrical current that depolarizes critical mass of myocardial ceils
– When cells repolarize, sinus node usually able to recapture role as heart pacemaker
• In cardioversion, current delivery synchronized with patient’s ECG
• In defibrillation, current delivery is unsynchronized
DefibrillationDefibrillation
Copyright © 2007, 2004, 2000, Mosby, Inc., an affiliate of Elsevier Inc. All Rights Reserved.
Fig. 36-21
DefibrillationDefibrillation
Copyright © 2007, 2004, 2000, Mosby, Inc., an affiliate of Elsevier Inc. All Rights Reserved.
Fig. 36-20 A and B
Paddle Placement for DefibrillationPaddle Placement for Defibrillation
Implantable Cardioverter Defibrillator (ICD)Implantable Cardioverter Defibrillator (ICD)
• Device that detects, terminates life-threatening episodes of tachycardia or fibrillation
• NASPE-BPEG code
• Antitachycardia pacing
Implantable Cardioverter- Defibrillator (ICD)Implantable Cardioverter- Defibrillator (ICD)
Fig. 36-22Copyright © 2007, 2004, 2000, Mosby, Inc., an affiliate of Elsevier Inc. All Rights Reserved.
Invasive Methods to Diagnose and Treat Recurrent DysrhythmiasInvasive Methods to Diagnose and Treat Recurrent Dysrhythmias
• Electrophysiologic studies
• Cardiac conduction surgery
– Maze procedure
– Catheter ablation therapy
hyperkalemiahyperkalemia
hypocalcemiahypocalcemia
ST elevation or flagST elevation or flag
“How will I know what to do?” you ask“How will I know what to do?” you ask
• Treat the patient, not the rhythm - is a good place to start
• Anticipate the problem
• Know your drugs
• Know CPR
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