EKG Block 1 Flashcards
When is an EKG indicated?
Syncope
Episodic FADS: fatigue, angina, dizziness, Sob
Palpitations
Transient A-Fib/Flutter neuro events
What are the current speeds through the different areas of the heart?
SA/AV- 0.01-0.02m/s
Atria/Ventricles- 1m/s
PF- 2m/s
Define Automaticity
Define Excitability
Ability to discharge spontaneously w/out stimulus
Ability to depolarize by stimulus
Define Chronotrophy
Define Inotrophy
Define Dromotrophy
Affecting HR
Affecting myocardial contractility
Affecting conductivity
What does a small box on ECG paper mean?
What do the heavy black lines mean?
0.1mv in height, .04 seconds in width
5 squares= .5mv, .2 sec
What does the X and Y axis on ECG paper represent?
X= time, 1mm=.04sec 5mm=0.20sec Y= voltage, 10mm= 1mv (two large boxes)
Define ECG Amplitude
What factors causes it to inc and dec?
Height, measured from baseline in milivolts
Inc- hypertrophy
Dec- COPD
What are the parts of a 12 lead ECG?
Which one is typically used for the rhythm strip?
Six limb Bipolar- 1, 2, 3, AVR, AVL, AVF
Six Chest Percordial- V1-6
Lead 2
What do leads 1, 2 and 3 measure/record?
Where are leads V1-6 placed?
1= RA to LA 2= RA to LL 3= LA to LL
V1= R4IS V2= L4IS V3= Between V2 and V4 V4= 5ICSMCL V5= 5ICSAAL V6 5ISMAL
What underlying issues can cause an abnormal QRS complex?
HEV FACETIME
What can cause the T wave to be tall/peaked?
Localized= MI General= hyperkalemia
What can cause the T wave to be inverted?
General= pericarditis
Localized= MI
V5, V6, aVL= LVH/BBB
V1/V2= RVH/BBB
What can cause the T wave to be flat?
Ischemia
Evolving infarction
Hypokalemia
What can cause the T wave to be elongated/bizarre?
Acute cerebral disease
T wave indicates what occurrence?
What does the U wave indicate?
T= ventricle repolarization
U= Perkinje fiber repolarization
What is the normal distance of the U wave?
What can cause it to be abnormal?
Norm= >1mm best at V3
Over 1mm= abnormal due to Hypo K, Ca, Mg
What does a negative deflection on the U wave indicate?
LAD
L main disease
Norms and abnormals of PR segment
Normally isoelectric
Depressed- pericarditis
Elevated- atrial infarction
What does the J Point mean?
Point where QRS ends and ST segment begins
Describes ST abnormalities (elevated/depressed)
What is the use of the R-R interval?
Used to determine Rate and Rhythm
Necessary for determining normal QT
What is the PR Interval?
From P wave to beginning of QRS
Measures time taken to travel from SA node/ectopic origin to ventricular muscle fibers
What is the normal duration of the PR interval?
What does a prolonged or shortened interval mean?
Norm= .12-.20 seconds Pro= AV block, Meds (Adenosine, BBs, CCBs, Digitalis) Short= low atrial/junctional foci, accelerated passage (WPW Syndrome, Lown-Ganong-Levine)
What does the QT interval include and what does it measure?
Beginning of Q to end of T
Measures total ventricular systole time
What factors can change the QT interval?
What is used to measure the corrected QT interval?
HR, Age, Gender, Autonomic tone
QTc- based on gender and HR
What is the RoT for the QT interval
QT should be <1/2 of RR
What is a normal QT inteval for men and women?
M- <420 msec
F- <430
What does a prolonged QT interval mean and what can cause it?
Delayed repolarization Predisposes to ventricular dysarhythmias Congenital/Rheumatic heart Low K Mg Ca Meds- Levafloxacin, Azithromycin, Zofran, Diflucan, Amiodarone
What would be considered a prolonged QT interval in men/women?
How is it treated?
M- >450
F- > 470
Tx w/ BB
What can cause a shortened QT interval?
Hyerkalemia
Hypercalcemia
Digitalis
What are the normal ranges for QRS Complexes, T Wave, PR Interval and QT Interval?
QRS- 1 to <3 boxes, .04-.11 sec
T- 2/3 height of R wave
PR- 3-5 boxes, .12-0.2 sec
QT- <1/2 R-R distance
What is the number sequence for determining rate on ECG paper?
300 150 100 75 60 50
When is the “6 Second Method” to determine the rate?
How is it done?
Useful with bradycardia or irregular rhythms
Two consecutive 3 second intervals
Count number of R waves
Multiply by 10
How is a normal Peds ECG different than an adult?
\+100 bpm Sinus aarythmia Longer QTC Dominant R V1-3 RSR V1 Pattern T-wave inversion V1-3
What two events occur and create Tachycardia Cardiomyopathy
Incessant SVT
Uncontrolled ventricular rates
How can re-entry tachycardia be terminated?
Vagal maneuver
IV meds
How is SVT diagnosed?
12 lead EKG
Holter monitor x 24-48hrs
Continuous loop recorder x 1mon
When/why is Electrophysiologic testing done?
Distinguish between SVT or Ventricular Tachycardia
How are SVTs initiated?
Paced pre-mature beats
Define Stable Tachycardia
No hemodynamic compromise
Define Unstable Tachycardia
Evidence of hemodynamic compromise:
HOTN, Angina, AMS, HF
Sinus tachycardia is almost always a response due to ? and never exceeds ? BPM
Stress
180
Define Atrial Tachycardia and what are the two types?
SVTs originating from focal anatomic areas in atria and propogate in centrifugal pattern
AVNRT- nodal
AVRT- re-entrant
Define Paroxysmal Atrial Tachycardia
Rapid firing of irritable atrial focus between 150-220 bpm
Define Paroxysmal Junction Tachycardia
Focal tachycardia originating in AV junction at 150-250 bpm
Define Junctional Tachycardia
Tachycardia w/out P waves
Negative deflection @ end of leads 2, 3, and aVF= retrograde P wave
It is impossible to distinguish Junctional Tachycardia from what other rhythm on ECG?
AVN Re-Entry Tachycardia
What are the characteristics of AVNRT
Functional, unidirectional block in AV node leading to retrograde conduction and continuous re-entry circuit
120-220 bpm
P waves are inverted/buried
Narrow QRS complex unless BBB is present
What is the most common SVT and who is it seen in?
AVNRT
Young adults
Pregnancy/menstrual cycles
How is AVNRT treated?
Electrophsiology and catheter ablation
Characteristics of AVRT
Anatomic bypass bundle between atria and ventricles w/ no delay
Pathway stimulates atria leading to paroxysmal tachycardia
AVRT is seen in what cardiac syndromes?
Wolf Parkinson White
LGLS
Define Orthodromic AVRT
Most common
Impulse travels out of AV node but return to atria through Kent bundle
Presents as narrow complex tachycardia
Define Antidromic AVRT
Impulse travels from AV to kent bundle to AV node causing wide complex tachycardia
What are the characteristics of WPW Syndrome
PR interval <0.12
AV node is bypassed
D wave at beginning of QRS causing impulse delivered to myocardium instead of normal conduction route
Widened QRS complex
Inverted T wave
Atria reactivated by ventricles causing rapid, regular tachy in 50-80% of PTs
What is WPW Type A pattern and what does it mimic?
What is WPW Type B pattern and what does it mimic?
L sided accessory pathway with tall Rs in V1-3; RVH
R sided accessory pathways with tall R and inverted T in inferior leads; LVH
Orthodromic AVRT in PTs w/ WPW Syndrome looks like ?
Antidromic looks like ?
Ortho- SVT, treated as SVT
Anti- LVH, treated as LVH
What meds are not used in the treatment of Antidromic AVRT in PTs with WPW Syndrome?
ABCD meds- may block AV node and increase HR
Characteristics of LGLS
PR Interval <0.12 sec due to James fibres
Normal QRS width and normal ventricular conduction through pathway
No delta
Paroxysmal tachycardia
Characteristics of A-Fib
No P wave
Irregularly irregular
What is the etiology behind A-Fib
PIRATES Pulmonary- OSA, PE, Pneumonia, COPD Rheumatic Dz/Mitral Regurg Alcohol/Anemia Thyrotoxicosis/Toxins E+/endocarditis Sepsis/Sick sinus syndrome
Define Paroxysmal, Persistent, Permanent and Recurrent A-Fib
Paroxysmal- resolves in 7 days
Persistent- Last longer than 7 days
Perm- always there and NEVER goes away
Recurrent- two or more episodes
All A-fib cases must be ?
Anticoagulated
How is A-Fib rhythm and rate controlled
Rhythm- cardioversion, antiarrhythmic
Rate- BBs, CCBs
A-Fib PTs without HOTN can be given what meds for rate control
Esmolol Metoprolol Verapamil Diltiazem Digoxin
New onset A-Fib in PTs that are good candidates for cardioversion should be anticoagulated with which direct acting PO meds?
Dabigatran
Apixaban
Rivaroxaban
Edoxaban
Half of A-Fib cases revert to sinus in ? days
What is the fundamental component of management?
3-4days
Restore/maintain sinus or allow recurrence/progression to permanent A-Fib
All new A-Fib cases get ? procedure prior to conversion?
Transesophageal echo or
Anticoagulate 4wks prior and after procedure
What does a Cha2DS2VASc score of 0-1 or 2 mean?
0-2= consider aspirin \+2= anticoagulate
Characteristics of A-Flutter
Atrial rate regular, 250-300 bpm, variable ventricle rate
Characteristics saw tooth pattern
What is the etiology behind atrial flutters?
pericardial Dz
LAE/RAE
Hypoxia
Hyper/pothyroid
What are the S/Sx of Atrial Flutter
ASx - poor CO
How is Atrial Flutter treated?
Control ventricle rate w/ BB/CCB
Inc risk of recurrence= catheter ablation as definitive treatment
Tx w/ conversion, rate control and antiarrhythmias
If persistent, anticoagulate, but is rare
What medication can be used IV to attempt to treat atrial flutter?
Ibutilide
Atrial flutter should last less than 48hrs or ? needs to be performed?
Transesophageal echocardiogram to r/o clot in L atrial appendage
What is the INR limits for Atrial Flutter?
INR of 2-3 w/ Warfarin or
DARE for 4wks prior to minimize stroke
Define Ventricular Arrhythmias
Rhythms originating in ventricular myocardium or in His/Purkinje tissues between 150-250 bpm
Ventricular arrhythmias includes which ones?
PVCs
Non/Sustained ventricular tachycardia
Life threatening V-tach
Define Couplet
Define Non-Sustained VT
Define Sustained VT
Two consecutive PVCs
Three or more PVCs
+30 seconds
What are the etiologies of Ventricular Tachycardia
MI Structural heart Dz R on T Irritability, myocardia Drugs E+ disturbances
How does Ventricular Tachycardia clinically present?
Pulselessness
ASx/palpitations
Dec CO
Syncope
Define Paroxysmal V-Tach
Irritable ventricular focus
Consecutive PVC like complexes
Define R on T Phenomenon and why it’s important
PVCs hit T-wave and causes V-Tach
This is why conversions are synchronized to avoid shocking on T-waves
How is V-Tach managed in un/stable PTs
Unstable- synchronized conversion w/ 200J
Stable- Antiarrhythmia therapy w/ Procainamide, Amiodarone or Lidocaine
Define Torsades de Pointes and what causes them
Genetic/medication induced long QT syndrome over 440/460
Hypo Mg, K, Ca
How do you treat Torsades de Pointes
Unsynchronized conversion
Magnesium
What are the characteristics of Ventricular Fibrillation
Variable wide complex rhythm over 300bpm w/ no P wave
What is the etiology behind Ventricular Fibrillation
Hypothermia Acid base VT/Torsades, untreated Electrical shock MI infarction/ischemia
How does Ventricular Fibrillation present clinically
Pulseless
Non-functioning heart causing 50% of deaths w/ CAD
Define PEA
Any supraventricular rhythm w/out an effective/detectable pulse caused by the 5 H’s and 5 T’s that presents as pulseless, non-functioning heart
What are the 5 H’s of ACLS
Hypovolemia Hypoxia H+ excess Hypo/perkalemia Hypothermia
What are the 5 T’s of ACLS
Tamponade Toxins Tension Pneumothorax Thrombosis, pulmonary Thrombosis, coronary
What will a Sinus Block/Sinus arrest look like
Dropped P wave and QRS
Unhealthy SA node may temporarily fail to pace for one cycle
No P wave
Define Sick Sinus Syndrome
Arrhythmic caused by SA node dysfunction w/ unresponsive supraventricular automaticity foci
Sick Sinus Syndrome manifests as ? and presents w/ ?
Sinus brady without normal escape mechanisms
May present w/ Brady-Tachy Syndrome
What is the etiology behind Sick Sinus Syndrome
How does it present in clinic?
CADz
Presents with palpitations, light headed and syncope
Define Pseudo Sick Sinus Syndrome
Athletes w/ resting sinus brady
Holster/Pacemaker
Define an AV Block
Impacted conduction from atria to ventricles
Define First Degree AV Block
Regular rhythm with normal P waves and QRS
PR interval >0.20 sec
What is the etiology behind First Degree AV blocks?
Athlete
Increases w/ age
Medications
Define a Second Degree AV Block Mobitz Type 1
Irregular PR interval getting progressively longer until QRS is dropped
Normal P wave interval
What is the etiology behind a Second Degree Block
Normally ASx
Possible Sx from bradycardia
Define Second Degree Heart Block Mobitz Type 2
Prolonged PR interval w/ sudden dropped QRS complexes
Atrial depolarizations are totally blocked
What is the etiology behind Second Degree Heart Block Mobitz Type 2
Large MIs
Damage to AV node (RCA)
Medications
How does Second Degree Heart Block Mobitz Type 2 present in clinic and what is the treatment?
Low CO
Possible pacemaker
Define Third Degree Block
Total block of conduction to ventricles
Regular rhythm-
40-60 if junctional
20-40 if ventricular
What is the etiology behind 3* Blocks?
Damage to AV node
IMI
MI at infra-nodal level
UNLIKELY from meds
How do 3* AV Blocks present
ASx to dec CO
Cannon A waves from valaves closing when chambers are firing
How are 3* blocks treated?
Pharmacotherapy
Pacing
When do PR intervals increase?
First degree AV block
Wenckebach cycles
Mobitz w/ QRS drops
When do PR intervals decrease?
When are PR intervals variable?
WPW Syndrome
3* Block
When are there P waves without WRS complexes?
Wenckebach
Mobitz
3* block
How is unstable bradycardia treated?
1mg Atropine or,
Isoproterenol infusion
Temporary pacemaker
How is stable bradycardia treated?
Remove any medications
Implant pacemaker- especially if Mobitz II and 3* AVB
Define BBB
QRS greater than 0.12sec
Recognized by R,R’ in specific leads of ECG
Define Intraventricular Conduction Delay
QRS between 0.10 - 0.12sec
Where do you look on the ECG to find a R BBB and a L BBB?
R- V1, 2
L- V5, 6
What etiologies cause R BBB?
Atrial Septal Defects Senile Degeneration Ischemic Heart Disease Cardiomyopathy Massive PE RVH Normal Variant
What characteristics will be seen in ECG paper with a R BBB?
QRS > 0.12
RSR’ in V1 or V2
Wide S in V4-6
V1 and V2- ST depression and Inverted T
What are the etiological causes of L BBB?
Idiopathic degeneration conduction system Dz Ischemic Heart Dz MI New L BBB c/w STEMI Cardiomyopathy Aortic Stenosis HTN/LVH Hyperkalemia Normal Variant (unusual)
What will be seen on ECG paper during a L BBB?
QRS > 0.12
High voltage S wave V1-2
Tall R wave V5-6, 1 and aVL
Slurred notch in any of above
V5, V6, 1 and aVL- ST depression and Inverted T
Left BBB confounds ECG interpretation for what three things?
Ischemia/infarction
Ventricular hypertrophy
ST/T wave changes
What does the R Coronary Artery supply?
What does the L Coronary Artery supply?
Posterior division of L BB and AV node
R BB and Anterior division of L BB
What are the 4 Fascicular Blocks
Acute MI (LAD)
HTN
Aortic stenosis
Dilated cardiomyopathy
Where will an Anterior Fascicular Block be seen on ECG paper?
Q1, S3, 2, and aVF
Normal/slightly wide QRS
Where will a Posterior Fascicular Block be seen on ECG paper?
S1Q3- S in L1, Q in L3
Right axis deviation
Normal/slightly widened QRS
Why are posterior fascicular blocks rare?
Usually dual blood supply
Define Axis
Direction of movement of depolarization that spreads through heart to stimulate the myocradium
What part of the heart beat identifies contraction of the myocardium?
QRS
Which way does the QRS point on ECG paper?
Down and L due to L ventricle wall thickness
Which two leads are the key ones for determining the axis?
1 and aVF
Which wax does the axis point during hypertrophy and MIs?
Hypertrophy- towards trophied side
MI- away from side w/ infarct
What are the causes of L Axis Deviation
LVH Inf MI L Ant Fasc. Block L BBB Paced Rhythm WPW Syndrome
What are the causes of R Axis Deviation?
RVH Lateral MI L Post Fasc Block Acute Lung Dz (PE) COPD
What are the causes of Extreme R Axis Deviation?
V-Tach
Hyperkalemia
What is the next step after identifying an axis deviation for better localization?
Find next best isoelectric lead
Vector is 90* from lead
Known quadrant allows axis vector determination
Define Horizontal Axis
R Wave Progression
Determined w/ precordial leads
Define Horizontal Zone of Transition
How deflection moves across precordial leads
What are the normals seen in Horizontal Zone of Transistion?
Norm= negative in V1
Transition= + in V6
Normal zone= V2-4
What are the causes of poor R Wave progression?
What needs to be checked here for operator error?
Anterior Infarction
RVH
Chronic Lung Dz
Obesity
*Check for lead reversal
Define Acute Coronary Syndrome
Spectrum from unstable angina to NSTEMI
Define Angina
Chest pain from ischemia
Define Ischemia
Lack of O2 to myocardial muscle
Define Unstable Angina
Partial clot that can occur without case and last 15-20min
Poor response to Nitro
Dx on 1st episode
Define Stable Angina
Predictable, usually w/ activity or stress
Dx only after work up for angina
Define Variant/Printzmetal Angina
Chest pain from a coronary artery spasm that can occur at rest/night in a non-atherosclerotic vessel
Thought to be caused by an endothelial dysfunction
Define Infarct
Cellular death and necrosis leading to permanent loss of myocardium and function
Define NSTEMI
AKA Non-Q wave MI
Difficult to distinguish from unstable MI w/out assessing markers
Markers= NSTEMI
No Markers= Unstable angina
Acute Coronary Syndrome has a 50% or higher prevalence in what three areas?
NSTEMI
65y/o
Men
What T wave changes will be seen with ischemia/infarction?
Peaked w/ hyperacute
Inverted w/ ischemia, infarct or injury
What ST changes will be seen with ischemia/infarction?
Depressed w/ ischemia
Elevated w/ injury/infarct
What Q wave changes will be seen with ischemia/infarction?
Start appearing w/ ischemia, injury, or infarct
Remain permanent if infarct occurs
What U wave changes will be seen with ischemia/infarction?
Seen on leads w/ pathological Q Waves
Exercise stress test can cause inversions
How do you measure for ST Segment Deviations?
Locate J point
Move 1.5 small boxes to R
Measure from baseline to isoelectric point
Define ST Depression
Represents sub-endothelial myocardial ischemia
Can be reversible and not necessarily associated w/ injury but can be a dire warning sign
Associated w/ T wave inversion
Define ST Elevation
Represents acute transmural myocardial injury and appears in areas of necrosis M= >2mm W= >1.5mm Or >1mm in 2 or more contigous leads Occurs w/out necrosis in variant angina
What are the four types of ST morphologies?
Concave- less concerning
Up Slope
Horizontal
Convex
What are the 3 evolving phases of change on an ECG during a MI?
Hyper/Early Acute
Evolved Acute
Chronic/Stabilized
What events occur during the Hyper/Early Acute phase of changes of a MI?
T waves increase and widen over area of injury
ST goes from concave to straight to convex up
Proceeds clinical Sxs
What events occur during the Evolved Acute phase of changes of a MI?
ST segments regress
T waves invert
Q waves develop after 1-2hrs
What events occur during the Chronic/Stable phase of changes of a MI?
ST returns to base line or slightly elevated after 2wks
Early perfusion therapy helps accelerate changes
Obtain new baseline ECG
What medications are considered in a sinus bradycardia DDx?
BB CCB Antiarryhythmics Digoxin Lithium
S/Sxs of sinud bradycardia?
If PT can compensate/ASx= athlete AMS Blurred vision Angina Cool/clammy skin Adeventitious lungs Dizz HOTN S3 heart sound Syncope
Define a Wandering Atrial Pacemaker
Site shifts between SA, atria and AV nodes
3 different p-wave morphologies
HR below 100bpm
What is the etiology of Wandering Atrial Pacemaker?
Idiopathic Vagal tone Dig toxicity Inflammed atrium VHD
Define Multifocal Atrial Tachycardia
Sped up version of WAP
Common in PTs w/ COPD
What characteristics about MAT are different that WAP?
SA node doesn’t pace
3 or more different shaped P-waves
+100bpm
Irregular P-r, R-R and P-P intervals
What is the etiology behind MAT?
Sever pulmonary Dz (COPD/Pneumonia)
Hypoxia
CHF
How does MAT manifest?
Palpitations
SOB
Chest pain
Lightheaded/syncope
What are the etiological causes of escape beats/rhythms
Dec automaticity- sinus node suppression, AMI, rheumatic disease, respiratory failure
Automaticity focus transiently escapes overdrive suppression- caffeine, adrenaline, digitalis, hyper thyroid, stretch
How do frequent pauses/escape beats clincially manifest?
Normally ASx
HOTN
Light headed/syncope
How does an atrial escape beat look on ECG?
Upright P wave
Occurs in healthy people related to sinus node suppression by meds, MI or respiratory failure
How does a ventricular escape beat look on ECG?
Widened QRS
How does a junctional escape beat look on ECG?
Inverted/absent P wave
What causes junctional escape beats?
Caffeine Nicotine ETOH/withdrawl Digitalis Hypoxia Sinus node ischemia Heart valve Dz Myocarditis
What causes ventricular escape beats?
Failed SA and AV pacing
Heart failure
Define Bigeminy
What is it associated with?
Irritable focus (atria/venticle) that couple to the end of a normal cycle
Hypoxia
What causes a run of PVCs
Irritable venticular focus fires spontaneous impulses
What criteria makes non-sustained V-Tach?
3 or more PVCs
Define R on T phenomenon
What does this definition justify in medical treatments?
PVC falls on a T wave and can cause deadly arrhythmia
Non-emergent conversions are synchronized to avoid T waves
What factors make the heart vulnerable to R on T Phenomenons?
Hypoxia
Hypokalemia
A normal P wave is seen inverted on which lead?
aVR
What heart issues is AKA the “Holiday Heart”
A-Fib
What are the intrinsic conduction rates?
SA Node 60 Atrial cells- 55 AV node- 45 His bundle- 40 Bundle branch- 40 Purkinje- 35 Myocardial- 30
The hearts BPMs are altered by ? and the m/s of conduction are altered by ?
Autonomic stimulus
Meds
How fast does ECG paper move?
What does that mean calibrated?
22mm/sec
10mm=1mv
How is HCM manageed?
ECG and holter monitor
No vigorous activities
Verapamil or BBs
Consider implant pacemaker