EKG Cumulative Final Flashcards
What are the indications for getting an EKG?
Unexplained syncope
Unexplained palpitations
Episodic Pain, Dizzy, Fatigue, SoB
Neuro events w/ transient A-Fib/Flutter
Sequence/Pathway of signals through the heart?
SA, AV Node, AV Bundle, Septum, Purkinje Fibers
What part of the pathway connects the atria to the ventricles and conducts impulses through the interventricular septum?
AV Bundle
What part of the conduction pathway stimulate the contractile cells of both ventricles, starting at the apex?
Purkinje Fibers
What are the intrinsic conduction speeds of the heart?
What can change these speeds?
SA and AV- 0.01 - 0.02m/s
Atria and Ventricle- 1 m/s
Purkinje Fibers- 2 m/s
Altered by medication
What are the BPMs of the different areas of the heart?
What alters these numbers?
SA Node- 60-100 Atrial cell- 55-60 AV Node- 45-50 Juntion- 40-60 His bundle- 40-45 Branch- 40-45 Purkinje- 35-40 Myocardial- 30-35 Ventricles- 20-40 Autonomic stimulus
Define Automaticity Define Excitability Define Chronotrophy Define Inotropy Define Dromotropy
Discharge spontaneously w/out stimulus Ability to be depolarized by stimulus Affecting HR Affecting contractility Affecting conductivity
Parasympathetic NS only affects ? part of heart?
Sympathetic NS affects ? parts?
Atria- Ach, decreases SA node pacing, dilates arteries
Atria and ventricles- Epi/NorEpi, Inc rate and force of contraction, constricts arteries
What are two factors that can alter general/diffuse amplitude?
Increases w/ hypertrophy
Decreases w/ COPD
Characteristics of a normal P wave?
Impulses through atria Upright in I, II, aVF and V2-6 Inverted in aVR Amplitude= up to 2.5mm Duration= <0.12 seconds
Characteristics of Q waves?
.04 sec or 1/4 the R wave
What does the QRS complex represent?
Depolarization through the ventricles
Normal is >.10 seconds
What does the T wave represent?
Repolarization of the ventricles
Upright in I, II, III, aVF, V3-6
Inverted in aVR
What two waves usually show concordance?
Normal T wave and QRS complex
What does the U wave represent?
Repolarization of Purkinje Fibers
Abnormally long in hypo Mg, Ca, K
What does the PR interval measure?
Time for signal to travel from SA to ventricular muscles
What does the QT interval measure?
Total time of duration of ventricular systole
How does a normal pediatric ECG appear?
HR +100
Longer QTc
Dominant R, inverted T in V1-3
Sinus arrhythmia
How do you test for premature atrial contractions?
How are they treated?
Holter/Event monitor
Echo
Labs w/ E+
Treat underlying cause, not the HR
What are the criteria for WAP?
HR below 100bpm
Multi focal rhythm originating from atria
3 different P wave morphologies
Pace maker shifts between SA node, AV node and Atria
What are the etiological causes of WAP?
How is it treated?
Idiopathic, Vagal tone, Dig toxicity, Inflamed atria, VHD
Treat underlying cause, usually ASx
What are the characteristics of MAT?
SA node doesn’t pace the heart, several groups of cells in atria do
3 or more morphologically different P waves
HR +100bpm
Irregular P-R, R-R and P-P intervals
What are the etiological reasons that cause MAT?
COPD- common finding
Pneumonia
Hypoxia
CHF
How do PTs with MAT present?
How is it treated?
Palipitations, SoB, Chest pain, Light headed, Syncope
O2
Treat underlying cause
Rate control- CCBs
How can you tell if a impulse originated from the SA node, Junction or Ventricle?
Atria= upright P wave Junction= inverted/absent wave Ventricle= widened QRS
When are Atrial Escape Beats usually seen and what causes them?
Healthy PTs from sinus node depression from meds, ischemia or respiratory failure
What can cause Junctional Escape Beats?
Stimulants, Nicotine Caffeine, Low E+ or Hypoxia
The occurrence of bigeminy beats is associated w/ what underlying issue?
Hypoxia
What is the first key to diagnosing SVTs?
12 lead
Electrophysiologic tests is definitive way to distinguish SVT from V-Tach
What are the criteria for an unstable tachcardic PT?
HOTN
AMS
Chest pain
HF (dyspnea)
Sinus tachycardia criteria= ?bpm?
Rarely exceeds 180bpm
What leads need to be examined when considering junctional tachycardia?
No P waves
Negative deflections in II, III, aVF can be retrograde P waves
Criteria for AVNRT
120-220
Buried/inverted P waves
Narrow QRS unless BBB is present
What is the most common SVT in all age groups?
What type of PT is it normally seen in?
AVNRT
Young adults and women exacerbated by pregnancy or menstrual cycle
What is the definitive treatment for AVNRT?
EP study and ablation
What type of defect is AVNRT?
What type of defect is AVRT?
Accessory pathway in/near AV node
Anatomic bypass bundle between atria and ventricles
What is the difference between Orthodromic AVRT and Antidromic AVRT?
Ortho- impulse travels down AV node but return to atria through Kent bundle causing narrow tachycardia
Anti- impulse travels down Kent bundle and up to AV node causing wide complex tachycardia
WPW Type A pattern is seen ? and mimics?
WPW Type B pattern is seen ? and mimics?
L sided pathway w/ tall R in V1-3 mimicing RVH
R sided path w/ tall R and inverted T in inferior leads that mimics LVH
Orthodromic WPW look like ? so it’s treated as such
Antidromic WPW looks like ? so it’s treated as such
SVT
VT
When/where do we not use ABCD medications in order to prevent blocking AV node and speeding the heart up?
AVRT- WPW Antidromic
What are the characteristics of LGL Syndrome?
PR interval is <0.12sec
Normal QRS
No delta wave
Paroxysmal tachycardia
Characteristics of A-Fib?
No P wave
Irregularly irregular
What are the causes of A-Fib?
PIRATES Pulmonary Ischmia Rheumatic HDz Alcohol/Anemia Thyroid/Toxins E+/Endocarditis Sepsis/SSS
Time frame for paroxysmal, persistent and permanent A-Fib?
Paroxysmal- less than 7 days
Persistent- more than 7 days
Permanent- always there even when medications are used
All A-Fib PTs must be ?
Anticoagulated
How is A-Fib managed?
Acute and no HOTN= rate control w/ DMV ED
New onset and good conversion candidates= DARE
Transesophageal echo prior to conversion or anti-coag for 4wks before and after
What are the BPMs for A-Flutter?
250-300
What leads are examined when considering A-Flutter?
How is A-Flutter diagnosed?
Counterclockwise- II, III, aVF
ECG
How is A-Flutter treated?
Control ventricular rate w/ BB/CCB
Ablation is primary definitive Tx due to reoccurrence
Can treat w/ cardioversion, rate control, antiarrhythmics
How is A-Flutter treated?
IV Ibutilide- 65% effective
Cardioversion- 95% effective
Prior to converting A-Flutter, PTs INR must be below ? on what drugs?
INR between 2-3 w/ Warfarin or,
DARE 4wks prior to conversion
What are the criteria/characteristics for V-Tach?
150-250bpm
Dissociated P waves
Wide complexes
Define R on T Phenomenon
PVC hits a T wave and causes V-Tach (shark fin appearance)
How is V-Tach managed?
Unstable= Synchronized conversion @ 200J Stable= Procainamide, Amiodarone, Lidocaine Pulseless= defibrillation
How is Torsades de Pointes treated?
Unsynchronized conversion if unstable
IV Magnesium sulfate
What are the characteristics of V-Fib?
Variable wide complex rhythm over 300bpm and no P waves
What are the 5 Hs and 5Ts of PEA?
Hypovolemia, Hypoxia, H+ excess, HypoK, Hypotemp
Tamponade, Toxins, Tension Pneumo, Thrombosis
Define SSS
Dropped P wave and/or QRS complex with escape contraction that manifests as sinus brady w/out normal escape mechanisms
What is the etiology, presentaiton, Dx and Tx for SSS?
Etiology: CAD
Presents: palpitations, light headed, syncope
Dx: holter monitor
Tx: pacemaker
What are the two types of 2* AV blocks?
Mobitz Type 1- Wenckebach (going, going, gone)
Mobitz Type 2 (duck duck goose)
Wenkebach Blocks can be caused if what vessel is occluded?
RCA
3* blocks are rarely caused by ?
They can present with what unique characteristic?
Medications
Cannon A Waves
How is Bradycardia treated?
Unstable- Atropine 1mg or Isoproterenol infusion, temp pace maker
Stable- remove medications, consider implant pacemaker especially if brady is caused by Mobtiz 2 or 3* Block
A BBB is defined by what finding on EKG?
What if it’s between 0.10-0.12?
QRS longer than 0.12 seconds
QRS that is 0.10-0.12- defined as intraventricular conduction delay
What are the causes of RBBB?
RANCID PE
RVH ASD Normal variant Cardiomyopathy Ischemia Degeneration Massive PE
What leads are examined when investigating RBBBs?
Wide “slurred” S in I, V4-6
Depressed ST, Inverted T, or RSR’ V1 or V2 (R’ taller than R)
What can cause LBBBs?
INLAND HH
Ischemia Normal LVH Aortic stenosis New LBBB c/w STEMI Degeneration HTN HyperK
What are the criteria for LBBBs?
QRS > 0.12sec in any lead High S in V1 or 2 Tall r in V5 or 6, I and aVL ST depression in V5, V6 1 and aVL Inverted T in V5, V6 1 and aVL
What does the RCA supply?
What does the LCA supply?
Posterior LBB and AV node
RBB and anterior LBB
What leads are examined for an anterior fascicular block?
Q1S3 also II and aVF
Normal to slightly wide QRS
What leads are examined for a posterior fascicular block?
Why are these rare?
S1Q3 and RAD
Deep/wide S in I
Q in III
Dual blood supply
What types of occlusions can result in a bifasicular block?
RBBB + anterior fasicular block
RBBB = posterior hemi block
What types of occlusions can result in an anterior or 3* block?
Anterior hemi + posterior hemi= LBBB
RBBB + AFB + PFB= 3* block
What can cause LAD?
LVH Inferior MI LAFB LBBB WPW
What can cause RAD?
RVH Lateral MI LPFB Acute lung Dz (PE) COPD
What are the two things that can cause extreme RAD?
V-Tach
Hyperkalemia
Define Horizontal Zone of Transition
How deflection moves across precordial leads
What four things can cause poor R wave progression?
Anterior infarction
RVH
Chronic Lung Dz
Obesity