Coronary Artery Disease Complications Cardiac Arrhythmias/Dysrhythmias Conduction System Four Properties of Cardiac Tissue Automaticity – ability

Coronary Artery DiseaseCoronary Artery DiseaseComplicationsComplications

Cardiac Cardiac Arrhythmias/DysrhythmiArrhythmias/Dysrhythmi

asas Conduction SystemConduction System

Four Properties of Cardiac TissueFour Properties of Cardiac Tissue AutomaticityAutomaticity – ability to initiate an impulse – ability to initiate an impulse ContractilityContractility – ability to respond – ability to respond

mechanically to an impulsemechanically to an impulse ConductivitConductivity – ability to transmit an y – ability to transmit an

impulse along a membrane in an orderly impulse along a membrane in an orderly mannermanner

ExcitabilityExcitability – ability to be electrically – ability to be electrically stimulatedstimulated

Cardiac Conduction Cardiac Conduction SystemSystem

Specialized neuromuscular tissueSpecialized neuromuscular tissue

PR IntervalPR Interval::SA Node – upper R atrium through SA Node – upper R atrium through

Bachman’s BundleBachman’s BundleAV Node – internodal pathwayAV Node – internodal pathwayBundle of His Bundle of His

QRS ComplexQRS Complex: : Right and Left Bundle BranchesRight and Left Bundle BranchesPurkinje FibersPurkinje Fibers

Cardiac ConductionCardiac Conduction

Cardiac MonitoringCardiac MonitoringPQRS ComplexPQRS Complex

Cardiac Action Cardiac Action PotentialPotential

Calculating Heart RateCalculating Heart Rate EKG paper is a grid where time is measured along the horizontal axis. 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 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. 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. 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:Heart rate can be easily calculated from the EKG strip: Heart rate can be easily calculated from the EKG strip:Heart rate can be easily calculated from the EKG strip:

• When the rhythm is regular:When the rhythm is regular:

• the heart rate is 300 divided by the number of large squares between the QRS complexes.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).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: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. 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).e.g., if there are 7 R waves in a 6 second strip, the heart rate is 70 (7x10=70).

Cardiac MonitoringCardiac MonitoringCardiac RateCardiac Rate

Cardiac MonitoringCardiac MonitoringAmplitude / DurationAmplitude / Duration

12 Lead EKG12 Lead EKG

EKG LeadsEKG Leads

12-Lead EKG12-Lead EKG

Reciprocal EKG Reciprocal EKG ChangesChanges

Cardiac MonitoringCardiac MonitoringChest Lead PlacementChest Lead Placement

Cardiac Monitoring- Cardiac Monitoring- MCLMCL

Cardiac MonitoringCardiac MonitoringNormal Sinus RhythmNormal Sinus Rhythm

Cardiac MonitoringCardiac MonitoringPQRS ComplexPQRS Complex

Cardiac MonitoringCardiac MonitoringCardiac Rhythm Cardiac Rhythm

AnalysisAnalysis Analyze the P waves – rate/rhythmAnalyze the P waves – rate/rhythm Analyze the QRS complexes – Analyze the QRS complexes –

rate/rhythmrate/rhythm Determine the heart rateDetermine the heart rate Measure the PR IntervalMeasure the PR Interval Measure the QRS durationMeasure the QRS duration Interpret the rhythm Interpret the rhythm Clinical significance? Hemodynamic Clinical significance? Hemodynamic

status?status? Appropriate TxAppropriate Tx

Cardiac Monitoring Cardiac Monitoring Normal Sinus RhythmNormal Sinus Rhythm


EKG / Heart SoundsEKG / Heart Sounds


Atrial & Ventricular rhythmsAtrial & Ventricular rhythms: : regularregular

RateRate: 60-100 beats/min: 60-100 beats/min P wavesP waves: present consistent : present consistent

configuration, one P wave prior to configuration, one P wave prior to each QRS complexeach QRS complex

PR intervalPR interval: .12 – .20 sec and : .12 – .20 sec and constantconstant

QRS durationQRS duration: -.04 to .10 sec and : -.04 to .10 sec and constantconstant

Cardiac MonitoringCardiac MonitoringSinus DysrhythmiasSinus Dysrhythmias

Cardiac MonitoringCardiac MonitoringSinus BradycardiaSinus Bradycardia

SA Node discharges < 60 beats/ minSA Node discharges < 60 beats/ min

EtiologyEtiology: >parasympathetic stimulation / : >parasympathetic stimulation / vagus nervevagus nerve

AssessAssess: LOC, Orientation, VS, PO, pain, : LOC, Orientation, VS, PO, pain, escaped ventricular ectopyescaped ventricular ectopy

TxTx: If patient is symptomatic – raise legs : If patient is symptomatic – raise legs up, move patient, Atropine – ACLS up, move patient, Atropine – ACLS BradycardiaBradycardia

Cardiac MonitoringCardiac MonitoringSinus Tachycardia Sinus BradycardiaSinus Tachycardia Sinus Bradycardia

Cardiac MonitoringCardiac MonitoringSinus TachycardiaSinus Tachycardia

SA Node discharge > 100 beats/ minSA Node discharge > 100 beats/ min

EtiologyEtiology: Sympathetic stimulation – : Sympathetic stimulation – normal or abnormal responsenormal or abnormal response

TxTx: Treat underlying cause: Treat underlying causeCardiac Supply ProblemsCardiac Supply ProblemsCardiac Demand ProblemsCardiac Demand Problems

E.g., hypovolemia, hypoxemia, anxiety, pain, E.g., hypovolemia, hypoxemia, anxiety, pain, anemia, anginaanemia, angina

Regular Narrow QRS - AdenosineRegular Narrow QRS - Adenosine

Sustained Sustained Tachy / Brady Tachy / Brady DysrhythmiasDysrhythmias Chest discomfort, or pain, radiation to jaw, back, Chest discomfort, or pain, radiation to jaw, back,

shoulder or upper armshoulder or upper arm Restlessness, anxiety, nervousnessRestlessness, anxiety, nervousness Dizziness, syncopeDizziness, syncope Change in pulse strength, rate, rhythmChange in pulse strength, rate, rhythm Pulse deficitPulse deficit Shortness of breath, dyspneaShortness of breath, dyspnea Tachypnea, OrthopneaTachypnea, Orthopnea Pulmonary ralesPulmonary rales S3 or S4 heart soundsS3 or S4 heart sounds Jugular vein distentionJugular vein distention Weakness, fatigueWeakness, fatigue Pale, cool skin, diaphoresisPale, cool skin, diaphoresis Nausea, vomitingNausea, vomiting Decreased urine outputDecreased urine output HypotensionHypotension

Cardiac MonitoringCardiac MonitoringPSVTPSVT

Cardiac MonitoringCardiac MonitoringParoxysmal Supraventricular Paroxysmal Supraventricular

Narrow QRS Tachycardia Narrow QRS Tachycardia (PSVT)(PSVT)

SA Node rate 100-280 beats/min - MSA Node rate 100-280 beats/min - Mean 170 ean 170 beats/minbeats/min

Etiology:Etiology: Pre-excitation syndrome, e.g., Wolff- Pre-excitation syndrome, e.g., Wolff-Parkinson White (WPW) SyndromeParkinson White (WPW) Syndrome

AssessAssess: Weakness, fatigue, chest pain, chest : Weakness, fatigue, chest pain, chest wall pain, hypotension, dyspnea, nervousnesswall pain, hypotension, dyspnea, nervousness

TxTx: Valsalva maneuvers: bearing down, : Valsalva maneuvers: bearing down, gagging, ocular pressure, vomiting, carotid sinus gagging, ocular pressure, vomiting, carotid sinus massage, massage, Meds: AdenosineMeds: Adenosine

Cardiac MonitoringCardiac MonitoringInterferenceInterference

Cardiac MonitoringCardiac MonitoringAtrial Flutter / Atrial Flutter /

FibrillationFibrillation

Cardiac MonitoringAtrial Flutter / Fibrillation

Cardiac MonitoringCardiac MonitoringAtrial FibrillationAtrial Fibrillation

Most Common dysrhythmia in the USMost Common dysrhythmia in the US Multiple rapid impulses from many Multiple rapid impulses from many

atrial foci, rate of 350-600/min—atrial foci, rate of 350-600/min—depolarize the atrial in a disorganized depolarize the atrial in a disorganized and chaotic manner – atrial quiverand chaotic manner – atrial quiver

ResultsResults: : No P wavesNo P wavesNo atrial contractsNo atrial contractsNo atrial kick No atrial kick Irregular ventricular responseIrregular ventricular response


EtiologyEtiology: MI, RHD with Mitral Stenosis, : MI, RHD with Mitral Stenosis, CHF, COPD, Cardiomyopathy, CHF, COPD, Cardiomyopathy, Hyperthyroidism, Pulmonary emboli, Hyperthyroidism, Pulmonary emboli, WPW Syndrome, Congenital heart WPW Syndrome, Congenital heart diseasedisease

** ** Mural Thrombi – increased risk for Mural Thrombi – increased risk for pulmonary & systemic pulmonary & systemic thromboemboli to brain & peripherythromboemboli to brain & periphery

AssessAssess: VS, PO, Pulse Deficit, chest : VS, PO, Pulse Deficit, chest pain, syncope, hypotensionpain, syncope, hypotensionSymptoms worsen with increased Symptoms worsen with increased

ventricular responseventricular response


Tx:Tx: TEE – Trans-esophageal echocardiogramTEE – Trans-esophageal echocardiogram

Identifies thrombi on valvesIdentifies thrombi on valvesMedications to decrease the ventricular Medications to decrease the ventricular

response - Metoprolol (Lopressor)response - Metoprolol (Lopressor)OxygenOxygenProphylactic anticoagulation Prophylactic anticoagulation

Lovenox - Coumadin – long termLovenox - Coumadin – long termCardioversionCardioversion


Tx:Tx: Medications to decrease the ventricular response Medications to decrease the ventricular response

Narrow QRS irreg rhythm–diltiazem; beta-blockersNarrow QRS irreg rhythm–diltiazem; beta-blockers Wide QRS reg rhythm – amiodaroneWide QRS reg rhythm – amiodarone Wide QRS irreg rhythm – digoxin, diltiazem, Wide QRS irreg rhythm – digoxin, diltiazem,

verapermil, amiodaroneverapermil, amiodarone

OxygenOxygenProphylactic anticoagulation Prophylactic anticoagulation CardioversionCardioversion


CardioversionCardioversionSynchronized countershock Synchronized countershock

50 – 100 Joules 50 – 100 Joules Avoids delivering shock during Avoids delivering shock during

repolarizationrepolarization Patent intravenous linePatent intravenous line Patient sedated – VersedPatient sedated – Versed OxygenationOxygenation ABCABC Assess: VS, PO, Monitor cardiac rate - Assess: VS, PO, Monitor cardiac rate -

rhythmrhythm Administer antidysrhythmic medicationAdminister antidysrhythmic medication

Cardiac MonitoringCardiac MonitoringJunctional Escape Junctional Escape

RhythmRhythm

Cardiac MonitoringCardiac MonitoringJunctional Escape Junctional Escape

RhythmRhythm Impulse generated from AV nodal Impulse generated from AV nodal

cells at the AV Junctioncells at the AV Junction

Escape pacemakerEscape pacemaker

Rate 40-60 beats/ minRate 40-60 beats/ min

Transient Transient

Assess: Patient hemodynamic Assess: Patient hemodynamic stabilitystability

Cardiac MonitoringCardiac MonitoringPremature Ventricular Premature Ventricular

ContractionsContractions

Cardiac MonitoringCardiac MonitoringNSR – V. Tach – V. NSR – V. Tach – V.

FibrillationFibrillation

Cardiac MonitoringCardiac MonitoringVentricular Ventricular TachycardiaTachycardia

Cardiac MonitoringCardiac MonitoringVentricular Ventricular

DysrhythmiasDysrhythmias


ContractionsContractions

Cardiac MonitoringCardiac MonitoringPremature Ventricular Premature Ventricular Contractions (PVCs)_Contractions (PVCs)_

Early ventricular complexesEarly ventricular complexesFollowed by compensatory pauseFollowed by compensatory pauseFit between two NSR beats - interpolated Fit between two NSR beats - interpolated

Unifocal, multifocal, couplet, triplets, Unifocal, multifocal, couplet, triplets, bigeminy, trigeminy, quadrigeminybigeminy, trigeminy, quadrigeminy 3+ = ventricular tachycardia3+ = ventricular tachycardia

EtiologyEtiology: myocardial ischemia, <K+, : myocardial ischemia, <K+, CHF, metabolic acidosis, airway CHF, metabolic acidosis, airway obstructionobstruction


Contractions (PVCs/ Contractions (PVCs/ Ventricular Tachycardia Ventricular Tachycardia

with Pulsewith Pulse AssessAssess: LOC, hemodynamic : LOC, hemodynamic

status-- continuous cardiac status-- continuous cardiac monitoring of rhythm & rate, VS, monitoring of rhythm & rate, VS, PO, peripheral perfusionPO, peripheral perfusion

TxTx: Underlying cause + Oxygen, : Underlying cause + Oxygen, Amiodarone IV bolus / InfusionAmiodarone IV bolus / Infusion

V. Tachycardia/V. FibrillationV. Tachycardia/V. FibrillationPulselessPulseless

TX: TX: CPR BLS - Airway, Breathing, CirculationCPR BLS - Airway, Breathing, Circulation Shockable Rhythm VT/VF: Defibrillate – 120-200 JoulesShockable Rhythm VT/VF: Defibrillate – 120-200 Joules

CPR x 5 cyclesCPR x 5 cycles

Check rhythm – shockable?Check rhythm – shockable? Defibrillate (biphasic 200 J / monophasic 360 JDefibrillate (biphasic 200 J / monophasic 360 J

Resume CPR Resume CPR

Epinephine 1 mg IV (repeat q3-5 mins) / VasopressinEpinephine 1 mg IV (repeat q3-5 mins) / Vasopressin CPR x 5 cyclesCPR x 5 cycles

Check rhythm – shockable?Check rhythm – shockable? Defibrillate (biphasic 200 J / monophasic 360 JDefibrillate (biphasic 200 J / monophasic 360 J

Resume CPR Resume CPR

Antiarrhythmics: amiodarone/lidocaineAntiarrhythmics: amiodarone/lidocaine Magnesium – torsades de pointesMagnesium – torsades de pointes

Advanced Cardiac Life SupportAdvanced Cardiac Life Support Defibrillation – V Fib / pulseless & polymorphic V tach Defibrillation – V Fib / pulseless & polymorphic V tach

Meds:Meds:

Cardiac MonitoringCardiac MonitoringV Fib - Agonal RhythmV Fib - Agonal Rhythm

Common Causes of Common Causes of DysrhythmiasDysrhythmias

CardiacCardiacAccessory pathways, conduction defects, Accessory pathways, conduction defects,

congestive heart failure, left ventricular congestive heart failure, left ventricular hypertrophy, myocardial cell hypertrophy, myocardial cell degeneration, myocardial infarctiondegeneration, myocardial infarction

Other ConditionsOther Conditions Acid-base imbalances, alcohol, coffee, tea, Acid-base imbalances, alcohol, coffee, tea,

tobacco, connective tissue disorders, drug tobacco, connective tissue disorders, drug effects or toxicity, electric shock, electrolyte effects or toxicity, electric shock, electrolyte imbalances, emotional crisis, hypoxia, shock, imbalances, emotional crisis, hypoxia, shock, metabolic disorders (e.g. thyroid), near-metabolic disorders (e.g. thyroid), near-drowning, poisoningdrowning, poisoning

Cardiac MonitoringCardiac MonitoringHeart Block Heart Block

11stst, 2, 2ndnd Types I & II Types I & II

Cardiac Monitoring Cardiac Monitoring Heart BlocksHeart Blocks

Cardiac Monitoring Cardiac Monitoring First Degree AV BlockFirst Degree AV Block

First Degree AV BlockFirst Degree AV Block: all sinus : all sinus impulses eventually reach ventriclesimpulses eventually reach ventricles

Prolonged PR Interval >.20Prolonged PR Interval >.20EtiologyEtiology: AV nodal ischemia – right coronary : AV nodal ischemia – right coronary

artery (inferior MI); hypokalemia, increased artery (inferior MI); hypokalemia, increased beta-blockers or calcium channel blockers, beta-blockers or calcium channel blockers, narcotics, excessive vagal stimulationnarcotics, excessive vagal stimulation

AssessAssess: Hemodynamically stable: Hemodynamically stable

TxTx: withhold offending medication; : withhold offending medication; oxygen; atropine, notify physician; oxygen; atropine, notify physician; observeobserve

Cardiac Monitoring Cardiac Monitoring Second Degree AV Block Second Degree AV Block

Mobitz Type I - Mobitz Type I - WenckebachWenckebach

Each impulse takes progressively longerEach impulse takes progressively longer Progressive lengthening of PR IntervalProgressive lengthening of PR Interval Followed by a dropped beat (missing QRS complex) & a Followed by a dropped beat (missing QRS complex) & a

pausepause May need temporary transvenous pacerMay need temporary transvenous pacer

Etiology: Etiology: Often transient following anterior / Often transient following anterior / inferior wall MI – may revert to 1inferior wall MI – may revert to 1stst Degree AV Block Degree AV Block

Assess: Assess: Hemodynamic stabilityHemodynamic stability

TxTx: Atropine / May require Temporary : Atropine / May require Temporary Transcutaneous Pacemaker / CPR / ACLS ProtocolTranscutaneous Pacemaker / CPR / ACLS Protocol

Cardiac Monitoring Second Degree AV Block

Mobitz Type I - Wenckebach

Cardiac Monitoring Cardiac Monitoring Second Degree AV Block Second Degree AV Block

Mobitz Type IIMobitz Type II

EtiologyEtiology: Infranodal block in one of the : Infranodal block in one of the bundle branchesbundle branches Dropped QRS complex without progressive Dropped QRS complex without progressive

lengthening of PR intervallengthening of PR interval P wave with no QRS complex followingP wave with no QRS complex following Random blockRandom block May progress to 3May progress to 3rdrd Degree AV Block – need for Degree AV Block – need for

permanent pacerpermanent pacer

AssessAssess: Hemodynamic stability: Hemodynamic stability

TxTx: Atropine / Transcutaneous pacemaker / : Atropine / Transcutaneous pacemaker / CPR / ACLS ProtocolCPR / ACLS Protocol

Cardiac Monitoring Cardiac Monitoring Third Degree AV BlockThird Degree AV Block

No sinus impulses conduct to the ventriclesNo sinus impulses conduct to the ventricles AV dissociation – rate: 40/minAV dissociation – rate: 40/min PR interval not constant – no relationship with P PR interval not constant – no relationship with P

and QRS complexand QRS complex Ventricular pacemaker – may abruptly fail Ventricular pacemaker – may abruptly fail

causing ventricular asystolecausing ventricular asystole

EtiologyEtiology: Anterior Wall MI; hypoxemia, : Anterior Wall MI; hypoxemia, electrolyte disturbances, cardiac surgeryelectrolyte disturbances, cardiac surgery

Cardiac Monitoring Cardiac Monitoring Third Degree AV BlockThird Degree AV Block

AssessAssess: Hemodynamic stability: Hemodynamic stability

TxTx: :

CPR CPR ACLS Protocol ACLS Protocol Pacemaker Pacemaker

Cardiac MonitoringCardiac MonitoringPaced RhythmPaced Rhythm

Cardiac MonitoringCardiac MonitoringPaced RhythmPaced Rhythm

Indications for Indications for Permanent PacemakerPermanent Pacemaker

Chronic atrial fibrillation with slow Chronic atrial fibrillation with slow ventricular responseventricular response

Fibrosis or sclerotic changes of the cardiac Fibrosis or sclerotic changes of the cardiac conduction systemconduction system

Hypersensitive carotid sinus syndromeHypersensitive carotid sinus syndrome Sick sinus syndromeSick sinus syndrome Sinus node dysfunctionSinus node dysfunction TachydysrhythmiasTachydysrhythmias Third-degree AV blockThird-degree AV block

Cardiac MonitoringCardiac MonitoringVentricular StandstillVentricular Standstill

Pulseless AsystolePulseless Asystole

CPRCPR

ACLS ProtocolACLS Protocol

Tx: Atropine, Epinephrine, Tx: Atropine, Epinephrine, dopamine dopamine

Pulseless AsystolePulseless Asystole

Shockable Rhythm? No – BLS/CPRShockable Rhythm? No – BLS/CPR Epinephrine 1 mg IV (may repeat q3-5 Epinephrine 1 mg IV (may repeat q3-5

mins)mins)

(or one dose of Vasopressin)(or one dose of Vasopressin) AtropineAtropine 5 cycles of CPR5 cycles of CPR Shockable rhythm? NO - CPRShockable rhythm? NO - CPR Yes – Pulseless V FibYes – Pulseless V Fib

Cardiac DysrhythmiasCardiac Dysrhythmias

ASSESS THE PATIENTASSESS THE PATIENT Treat the underlying causeTreat the underlying cause Support hemodynamicallySupport hemodynamically

Emergency Cardiac MedicationEmergency Cardiac MedicationCPRCPRTranscutaneous/Transvenous Transcutaneous/Transvenous

pacemakerpacemaker Information and emotional support Information and emotional support

to patient & familyto patient & family

New Cardiac AdvancesNew Cardiac Advances

Implantable cardioverter – Implantable cardioverter – defibrillator (AICD)defibrillator (AICD)

Automatic external defibrillator (AED)Automatic external defibrillator (AED)ABCDABCD

Cardiac Ablation TherapyCardiac Ablation Therapy

BLSBLS ACLSACLS

Documents

Coronary Artery Disease Complications Cardiac Arrhythmias/Dysrhythmias Conduction System Four Properties of Cardiac Tissue Automaticity – ability