EKGs Flashcards
To learn how to read an EKG and how to recognize important features (107 cards)
1
Q
How many seconds does one small horizontal box represent?
A
0.04 seconds (40 milliseconds)
2
Q
How many seconds does one large horizontal box represent?
A
0.20 seconds (200 milliseconds)
3
Q
How many small horizontal boxes make one large horizontal box?
A
5
4
Q
How many millivolts does one small vertical box represent?
A
0.1 millivolts
5
Q
What waves make up an EKG and what do they represent?
A
P Wave: Atrial Depolarization
QRS Wave: Ventricular Depolarization
T Wave: Ventricular Repolarization
U Wave: Purkinje Fiber Repolarization
6
Q
How do you calculate the rate?
A
300-150-100-75-60-50 OR If the EKG is a 10 second strip, you can count the number of QRS complexes and multiply by 6 (only if rhythm is regular)
7
Q
Describe where the leads should be placed on the patient.
A
V1: 4th intercostal space, right sternal border
V2: 4th intercostal space, left sternal border
V3: Between V2 and V4
V4: 5th intercostal space, left midclavicular line
V5: In line with V4, left anterior axillary line
V6: In line with V5, left midaxillary line
8
Q
What leads should you look at to determine the axis?
A
Lead I and aVF. If aVF is equivocal, look at lead II
9
Q
What degrees are each of the limb leads at (bipolar and unipolar)?
A
Bipolar limb leads include leads I, II, and III. Lead I is at 0 degrees. Lead II is at +60 degrees. and Lead III is at +120 degrees.
Unipolar limb leads include aVR, aVL, and aVF. aVR is at -150 degrees. aVF is at -30 degrees. And aVF is at +90 degrees.
10
Q
What is a normal axis delineated by?
A
Positive QRS deflection in Lead I and aVF
11
Q
What is a left axis deviation delineated by?
A
Positive QRS deflection in Lead I and negative QRS deflection in aVF
12
Q
What is a right axis deviation delineated by?
A
Negative QRS deflection in Lead I and positive QRS deflection in aVF
13
Q
True or False: Right axis deviation is normal for a pediatric patient.
A
True.
14
Q
In what instances will you see an extreme axis deviation on EKG?
A
- Ventricular rhythms (i.e. ectopy)
- Hyperkalemia
- Severe right ventricular hypertrophy (i.e. pulmonary hypertension)
- Lead malposition
15
Q
What is the difference between intervals and segments on an EKG?
A
Segments do NOT contain waves. Intervals do contain waves.
16
Q
Describe the PR interval.
A
Start of the P wave to the start of the QRS wave.
Normal Length: 120-200 milliseconds (3 small boxes to 5 small boxes OR 3 small boxes to 1 large box)
17
Q
What does a long and short PR interval indicate?
A
AV conduction abnormality.
Long: AV blocks
Short: Pre-excitation syndromes
18
Q
Describe the QRS interval.
A
Normal Length: 70-100 milliseconds (some books say <120 milliseconds)
19
Q
What does a wide and narrow QRS interval indicate?
A
Wide: Usually due to a bundle block
Narrow: Supraventricular origin
20
Q
Describe the QT interval.
A
Start of the Q wave to the end of the T wave
Ventricular depolarization and repolarization.
21
Q
What is a normal QT interval?
A
Men: 350-440 milliseconds
Women: 350-460 milliseconds
The T wave should fall at less than half of the R-R interval.
Women take longer to get ready
22
Q
Why do we often reference the corrected QT (or QTc) to determine the QT Interval length?
A
Because the QT interval changes with heart rate and is often only accurate if the heart rate is between 60 and 100.
23
Q
How do you calculate the QTc?
A
Bazett’s Formula: QT interval/ Square root of the R-R interval
Men: 350-440 milliseconds
Women: 350-460 milliseconds
Some research indicate that >480 milliseconds is concerning for prolonged/long QT
24
Q
What are we worried about with a long QT interval?
A
Risk of Torsades
25
What is the normal morphology of a P wave?
Normal P Wave Axis: 0 to +75 degrees
P waves should be upright in Leads I and II and down in aVR
Amplitude: <2.5mm in limb leads and <1.5mm in precordial leads
First 1/3 of the P wave corresponds to right atrial activation. Final 1/3 of the P wave corresponds to left atrial activation. Middle 1/3 is a combination of the two.
26
How will the P wave look in right atrial hypertrophy and left atrial hypertrophy?
Right Atrial Hypertrophy: Taller (>2.5mm)
Left Atrial Hypertrophy: Wider (>120 milliseconds)
27
What is P. Mitrale?
A biphid P wave with >40 milliseconds (1 small box) between peaks.
Classic for mitral stenosis
28
Where are Q waves normally seen?
In left-sided leads (I, aVL, V5, and V6)
Deep, narrow Q waves (>2mm) in Lead III and aVR can be a normal variant.
*Q waves indicate normal left to right depolarization of the septum*
29
What are pathological Q waves?
Q waves that are >1mm wide, >2mm deep, and/or more than 25% of the QRS complex in leads V1-V3
*Q waves should NOT be present in V1-V3*
30
What do the presence of pathological Q waves indicate?
Current or Old MI
Hypertrophic Cardiomyopathy
Infiltrative Cardiac Diseases
31
What are 3 key abnormalities of R waves that should NOT be missed?
1. Dominant R wave in V1
2. Dominant R wave in aVR
3. Poor R wave progression
32
True or False: A dominant R wave in V1 is normal in pediatric patients.
True
33
What EKG findings should cause you to obtain a posterior EKG?
Dominant R wave in V1 with accompanying ST depression in the anterior pre-cordial leads.
*Obtain a posterior EKG to look for a posterior MI*
34
What toxicity/overdose should you be thinking of when you see a dominant R wave in aVR?
Sodium Channel Blockade (i.e. TCA Overdose)
35
Describe R wave progression.
In Lead I, the R wave should be small. The R wave becomes larger throughout the precordial leads, to the point where the R wave is larger than the S wave in Lead V4.
36
What is the Sokolov-Lyon Criteria?
Helps determine if there is left ventricular hypertrophy.
LVH is present if:
- The R wave in aVL is > 11mm OR
- (S wave in V1 or V2) + (R wave in V5 or V6) > 35mm
37
True or False: Inverted T waves are a normal finding in children.
True.
38
Where is it normal to see inverted T waves on an EKG?
Leads III, aVR, and V1
*Of note, while an inverted T wave in Lead III can be a normal variant, if it is changed from previous EKGs...it is considered abnormal*
39
True or False: U waves enlarge as the heart rate slows.
True.
40
True or False: Inverted U waves are a normal variant.
False. Inverted U waves usually represent pathologic heart disease (i.e. CAD or MI, especially if in the presence of chest pain)
41
What is a Delta wave and what does it signify?
A Delta wave is a slurred upstroke to the QRS complex that is seen in WPW (pre-excitation syndrome)
42
What is an Epsilon wave and what does it signify?
An Epsilon wave is a small positive deflection at the end of the QRS complex that may indicate Arrythmogenic Right Ventricular Dysplasia.
*ARVD leads to an increased risk of ventricular tachycardia and death*
43
What is an Osborn wave and what does it signify?
An Osborn wave is a positive deflection of the J point commonly seen in: severe hypothermia, increased intracranial pressure, and hypercalcemia.
44
What EKG findings are concerning for a Right Ventricular Infarct?
ST elevation in V1 + ST elevation greater in Lead III than in Lead II (III > II)
*If concerned, do a right-sided EKG*
45
How do you diagnose a RBBB on EKG?
- Wide QRS (> 120ms)
- RSR' in V1-V3 ("M"-shaped QRS complex)
- Wide, slurred S wave in the lateral leads (I, aVL, V5, V6)
46
How do you diagnose a LBBB on EKG?
- Wide QRS (> 120ms)
- Dominant S wave in V1
- Broad, monophasic R waves in lateral leads (I, aVL, V5, V6)
- Absence of Q waves in lateral leads (I, aVL, V5, V6)
- Prolonged R wave peak time > 60ms in left precordial leads (V5-V6)
*A Q wave may still be seen in aVL*
47
How do you diagnose a Left Anterior Fascicular Block on EKG?
- Left Axis Deviation
- Small Q waves with tall R waves in Leads I and aVL
- Small R waves with deep S waves in Leads II, III, and aVF
- Increased QRS voltage in the limb leads
48
How do you diagnose a Left Posterior Fascicular Block on EKG?
- Right Axis Deviation
- Small R waves with deep S waves in Leads I and aVL
- Small Q waves with tall R waves in Leads II, III, and aVF
- Increased QRS voltage in the limb leads
49
What are the AHA Guidelines for diagnosing STEMI?
- ST elevation > 1mm in 2 contiguous leads OR
- ST elevation > 2mm in V2-V3 in males OR
- ST elevation > 1.5mm in V2-V3 in females
- ST depression of > 2mm in V1-V4 (may indicate posterior MI)
* Of note, a new or presumed LBBB is NOT considered a STEMI equivalent*
50
Which type of ST segment morphology is more concerning: Concave or Convex?
Convex is more concerning (think of a sad face)
51
What criteria do you use to diagnose a STEMI in a LBBB?
Sgarbossa Criteria
52
What is the Sgarbossa Criteria?
1. Concordant ST elevation > 1mm in leads with a positive QRS complex (score 5)
2. Concordant ST depression > 1 mm in V1-V3 (score 3)
3. Excessively discordant ST elevation > 5 mm in leads with a negative QRS complex (score 2)
A total score of ≥ 3 is reported to have a specificity of 90% for diagnosing myocardial infarction.
53
How do you diagnose Benign Early Repolarization (BER) on EKG?
- J point elevation mainly in precordial leads
- Concave ST elevation
- No Q waves or ST depressions
*Be cautious in diagnosing this in people >30 years old*
54
How do you diagnose Pericarditis on EKG?
- Diffuse ST elevations in multiple anatomic leads
- PR depressions
- NO ST depressions
- May have flipped T waves
55
How do you diagnose Brugada Syndrome on EKG?
Type 1: ST segment elevation in V1-V2 with coved ST slope into inverted T wave
Type 2: ST segment elevation in V1-V2 with a saddleback appearance
*Note: There are 3 types; however, Type 3 is no longer accepted*
56
How do you treat Brugada Syndrome?
Defibrillate
57
What is the significance of Brugada Syndrome?
Increased risk of sudden cardiac death
58
What is Wellen's Syndrome?
It is highly specific for critical stenosis of the LAD. Patients are at extremely high risk for extensive anterior wall MI within the next few days to weeks.
*It is concerning for ACS, but is NOT a STEMI*
59
How do you diagnose Wellen's on EKG?
- Deeply-inverted or biphasic T waves in V2-3 (may extend to V1-6)
- Isoelectric or minimally-elevated ST segment (< 1mm)
- No precordial Q waves
- Preserved precordial R wave progression
- Recent history of angina
- ECG pattern present in pain-free state
- Normal or slightly elevated serum cardiac markers
60
How do the two types of Wellen's differ?
Type I (A): Biphasic T wave with initial positivity and terminal negativity
Type II (B): Deeply and symmetrically inverted T wave
61
What do you want to do if you see Wellen's waves?
Do NOT stress test...repeat EKG and call Cardiology
62
What is the significance of aVR ST elevation?
Concerning for left main disease, coronary dissection, or severe 3-vessel disease
NOT a STEMI by AHA Guidelines
63
True or False: Give Plavix if you see ST elevation in aVR
False. Do NOT give Plavix to those who have ST elevation in aVR
64
What makes up the spectrum of Acute Coronary Syndrome?
Unstable Angina
NSTEMI
STEMI
65
What components make up the Heart Score?
```
History
EKG
Age
Risk Factors
Troponin (initial)
```
66
What does the Heart Score predict?
The Heart Score predicts 6-week risk of major adverse cardiac event
67
What is the goal of STEMI care and management?
Early recognition and disposition
68
What two ER managements of STEMI have the greatest mortality benefit?
1. Aspirin
| 2. Cardiac Defibrillator
69
When is Nitroglycerin contraindicated?
- If the patient has taken Viagara within the last 48 hours or Cialis within the last 72 hours
- Hypotension
- Posterior or Inferior MI
70
When do you NOT administer blood thinners in an ACS presentation?
Do NOT give Plavix to someone with aVR ST elevation on EKG
71
What is the Heparin dose for ACS?
60U/kg bolus (max 4000U), then 12U/kg/hr (max 1000U/hr)
72
What medications have mortality benefit long-term in ACS?
Beta-Blockers and ACE-Inhibitors
*Start within 24 hours of MI*
73
When should you initiate thrombolytics?
If unable to receive PCI or more than 120 minutes from PCI center
74
What are the ABSOLUTE contraindications to thrombolytics?
- Prior ICH
- Known structural cerebral vascular lesion
- Known malignant intracranial neoplasm
- Ischemic stroke within 3 months
- Suspected aortic dissection
- Active bleeding or bleeding diathesis (excluding menses)
- Significant closed head trauma or facial trauma within 3 months
- Intracranial or intraspinal surgery within 2 months
- Severe uncontrolled hypertension (unresponsive to emergency therapy)
*For streptokinase, prior treatment within the previous 6 months*
75
What are the RELATIVE contraindications to thrombolytics?
- History of chronic, severe, poorly controlled HTN
- Significant HTN on presentation (SBP >180 OR DBP >110)
- Traumatic or prolonged CPR (>10min)
- Major surgery <3 weeks previously
- History of prior ischemic stroke NOT within the last 3 months
- Dementia
- Recent (within 2-4 weeks) internal bleeding
- Noncompressible vascular punctures
- Pregnancy
- Active peptic ulcer
- Current use of anticoagulant with an INR >1.7 or PT >15 seconds
76
How do you dose tPA (Alteplase)?
*Infusion over 90 minutes*
1. 15 mg IV bolus -------------->
2. 0.75 mg/kg IV over 30 minutes (50mg max) --------->
3. 0.5 mg/kg IV over 60 minutes (35mg max)
Max Dose = 100mg
77
What is the definition of an NSTEMI?
Positive biomarkers without ST elevation
*May benefit from DELAYED catheterization*
78
What is the workup for ACS/Chest Pain in the ED?
1. EKG + 2 Large Bore IVs + Monitor
2. Labs: CBC, BMP, HCG, Troponin, Coags, BNP
If within 6 hours of symptom onset, consider CK and
CK-MB...may be positive before Troponin
3. Portable CXR
4. Aspirin 162-324mg PO
5. Nitroglycerin 0.4mg SL (if not contraindicated)
Followed by drip starting at 5-10mcg/min titrated to
pain control or hypotension
6. Plavix 600mg PO or Brilinta 180mg PO
Do NOT give with ST elevation in aVR
7. Morphine
8. Heparin (adjust dose to a PTT of 50-70 seconds)
9. Ask Cardiology about GpIIb/IIIa initiation
10. Beta-Blockers and ACE-I's within 24 hours
11. Admit to Cardiology/Telemetry floor
79
What are the three types of Heart Failure?
1. Normotensive Heart Failure
2. Hypertensive Heart Failure
3. Hypotensive Heart Failure
80
What should be your first step if you think your patient is presenting with Acute Heart Failure?
Assess their respiratory status: Are they in distress or no?
*If so, NIV versus ETT*
81
What is the initial work-up for Acute Heart Failure?
EKG
CXR
CBC, Chem-7, BNP, Troponin
*Do NOT forget your ABCs*
82
What is the goal in Normotensive Heart Failure management?
1. Diuresis (reduction of total body water and congestion)
| 2. Management of other conditions
83
What is the management of Hypertensive Heart Failure?
1. Consider NIV
2. Immediate Sublingual NTG (consider IV vasodilator)
3. IV Loop Diuretic
4. Continue to Reassess
84
What are the management goals in Hypotensive Heart Failure?
1. Treat underlying cause
2. Cautious IV fluids
3. If fluids do not work, start vasopressors/inotropes
4. May consider diuretic if congested (watch BP)
85
What are the inotropes that can be used in Hypotensive Heart Failure management?
1. Dobutamine: 0.5mcg/kg/min titrated up to 40mcg/kg/min
2. Milrinone: 50mcg/kg load ----> 0.375-0.75mcg/kg/min
3. Dopamine
86
What are the vasopressors that can be used in Hypotensive Heart Failure management?
1. Norepinephrine
2. Epinephrine
3. Neosynephrine
87
How do you diagnose Multifocal Atrial Tachycardia (MAT) on EKG?
3 or more distinct P waves with a heart rate over 100bps
*Seen in severe COPD and CHF; 60% mortality rate if associated with an acute exacerbation*
88
What are the four types of Atrial Fibrillation that you must delineate in order to determine treatment?
1. Stable Chronic Atrial Fibrillation
2. Stable Acute Atrial Fibrillation With Normal HR
3. Stable Atrial Fibrillation With Rapid Ventricular Rate
4. Unstable Atrial Fibrillation With Rapid Ventricular Rate
89
What is the CHADS2Vasc Score?
It calculates the stroke risk for patients with atrial fibrillation
It helps to determine the 1-year risk of a thromboembolic event in a non-anticoagulated patient with non-valvular atrial fibrillation
90
What components make up the CHADSVasc2 Score?
- Age
- Sex
- CHF History
- HTN History
- Stroke/TIA/Thromboembolism History
- Vascular Disease History
- Diabetes History
Score of 0: "Low" Risk (no anticoagulation)
0.2%/year
Score of 1: "Low-Moderate" Risk (possibly start anticoagulation)
0.6-0.9%/year
Score 2 or Greater: "Moderate-High" Risk (begin anticoagulation)
11%/year
91
What scoring tool can you use to determine bleeding risk for patients on Warfarin?
ATRIA Bleeding Risk
92
What components make up the ATRIA scoring tool?
```
Anemia
Severe Renal Disease
Age ≥ 75
Any Prior Hemorrhage Diagnosis
HTN History
```
Score <4: Low Risk
Score of 4: Intermediate Risk
Score >4: High Risk
93
When can you cardiovert someone who is in Atrial Fibrillation?
Generally, if the onset is less than 2 days ago
94
What are your two treatment options for someone who is in stable acute atrial fibrillation with a normal heart rate?
Anticoagulation versus Cardioversion
95
What are your treatment options for someone who is in stable atrial fibrillation with RVR?
Rate Control versus Rhythm Control
*Start with rate control*
96
What are the rate control medications for stable atrial fibrillation with RVR?
- Beta Blockers: Metoprolol or Esmolol
AVOID in acute CHF and COPD
- Calcium Channel Blockers: Diltiazem or Verapamil
- Digoxin
*AVOID if it is a wide complex Atrial Fibrillation*
97
What are the rhythm control medications for stable atrial fibrillation with RVR if rate control fails?
- Amiodarone
| - Procainamide
98
How do you treat unstable atrial fibrillation with RVR?
Synchronized cardio version (100-200J)
| Amiodarone
99
What is the MOA of Amiodarone?
Delays repolarization of the ventricles by potassium-channel blockade
100
What are the indications for Amiodarone?
1. Atrial Fibrillation (rate control) - 2nd Line
2. Atrial Fibrillation Cardioversion - 2nd Line
3. Monomorphic VT - 1st Line (if stable)
4. Polymorphic VT - Avoid if QT prolongation
5. Pulseless VT or VFib
101
What are the contraindications for using Amiodarone?
1. Prolonged QT
| 2. Thyrotoxicosis
102
What is the MOA of Adenosine?
Inhibits adenylate cyclase causing decreased flow of calcium ions into the AV node
103
What is the MOA of Procainamide?
Intermediate sodium channel blockade (which prolongs the QT interval)
104
What are some EKG characteristics of Ventricular Tachycardia?
- Very broad complexes (> 160ms)
- Extreme axis deviation (QRS positive in aVR and negative in I and aVF)
- AV dissociation (P and QRS complexes are at different rates)
- Brugada's Sign
- Josephson's Sign
- RSR' complexes with a taller "left rabbit ear"
105
What is Brugada's Sign?
The distance from the onset of the QRS complex to the nadir of the S-wave is > 100ms
106
What is Josephson's Sign?
Notching near the nadir of the S-wave
107
What is the treatment for Torsades?
Magnesium 1-2g IV
