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Cardiology > EKG Differentials > Flashcards

EKG Differentials Flashcards

(42 cards)

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1
Q

Lead I

Inverted P wave

A

• Ectopic atrial premature beat or rhythm
• AV junctional/ventricular premature complex or
rhythm with retrograde atrial activation
• Dextrocardia: Inverted P-QRS-T in leads I and aVL with reverse R wave progression in the precordial leads
• Reversal of right and left arm leads: Inverted PQRS-T in leads I and aVL with normal R wave progression in the precordial leads

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2
Q

Lead II

Tall peaked P wave

A
  • Right atrial abnormality/enlargement

* Bi-atrial abnormality

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3
Q

Lead II

Bifid P wave with peak-to-peak interval > 0.03 sec. and P wave duration > 0.12 sec.

A

• Left atrial abnormality/enlargement

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4
Q

Lead II

Inverted P wave

A

• Ectopic atrial premature beat or rhythm
• AV junctional/ventricular premature complex or
rhythm with retrograde atrial activation

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5
Q

Lead II

Sawtooth regular P waves

A
  • Atrial flutter

* Artifact due to tremor (e.g., Parkinson’s disease, shivering)

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6
Q

Lead II

Irregularly irregular baseline

A
  • Atrial fibrillation
  • Artifact due to tremor
  • Multifocal atrial tachycardia
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7
Q

Lead II

Multiple P wave morphologies

A
  • Wandering atrial pacemaker (rate < 100 bpm)
  • Multifocal atrial tachycardia (rate > 100 bpm)
  • Sinus or atrial rhythm with multiple atrial premature complexes
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8
Q

Lead V1

Tall upright P wave

A

• Right atrial abnormality/enlargement

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9
Q

Lead V1

Deep inverted P waves

A

• Left atrial abnormality/enlargement

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10
Q

Lead V1

Dome and dart P wave

A

• Ectopic atrial rhythm

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11
Q

No P Waves

P Waves present but hidden

A
  • Ectopic atrial rhythm or APCs (P waves hidden in preceding T wave)
  • Junctional rhythm or SVT (P wave buried in QRS)
  • Supraventricular rhythm with marked first-degree AV block (P wave hidden in preceding T wave)
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12
Q

No P Waves

P Waves not present

A
  • Sinoventricular conduction due to hyperkalemia
  • Marked sinoatrial exit block or sinus bradycardia with junctional or ventricular rhythm (escape or accelerated)
  • Sinus pause or arrest
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13
Q

PR Interval

Prolonged (> 0.20 seconds) PR interval

A

• First-degree AV block
• Complete heart block: PR interval varies, has no
constant relationship to the QRS, and may intermittently exceed 0.20 seconds
• Supraventricular or junctional rhythm with retrograde atrial activation: P wave inverted in lead II
• Atrial premature complex

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14
Q

PR Interval

Short (< 0.12 seconds) PR interval

A

• Short PR with sinus rhythm and normal QRS
• Wolff-Parkinson-White pattern: Delta wave, wide
QRS, ST-T changes in a direction opposite to main deflection of QRS
• Low ectopic atrial rhythm: PR interval usually > 0.11 seconds; P wave inverted in lead II
• Ectopic junctional beat or rhythm with retrograde atrial activation: PR interval usually < 0.11 seconds; P wave inverted in lead II

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15
Q

PR Segment Depression

A
  • Normals: < 0.8 mm
  • Pericarditis
  • Pseudodepression due to atrial flutter or Parkinson’s tremor
  • Atrial infarction: Reciprocal elevation in opposite leads; inferior MI usually evident
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16
Q

PR Segment Elevation

3

A

1 Normals: < 0.5 mm
2 Pericarditis: Lead aVR only
3 Atrial infarction: Reciprocal depression in opposite leads

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17
Q

Increased QRS duration 0.10 to < 0.12 seconds

11

Study These Flashcards
A 
1 Left anterior fascicular block 
2 Left posterior fascicular block
3 Incomplete LBBB 
4 Incomplete RBBB
5 Nonspecific IVCD 
6 LVH 
7 RVH 
8 Supraventricular beat or rhythm with aberrant intraventricular conduction 
9 Fusion beats
10 Wolff-Parkinson-White pattern
11 VPCs originating near the bundle of His (i.e., high in the interventricular septum)
18
Q

Increased QRS duration > 0.12 seconds

9

Study These Flashcards
A 
1 RBBB
2 LBBB 
3 Supraventricular beat or rhythm with aberrant intraventricular conduction
4 Fusion beats
5 Wolff-Parkinson-White pattern 
6 Ventricular premature complexes 
7 Ventricular rhythm 
8 Nonspecific IVCD 
9 Paced beat
19
Q

Low voltage QRS

7

Study These Flashcards
A 
1 Chronic lung disease 
2 Pericardial effusion 
3 Myxedema 
4 Obesity
5 Pleural effusion
6 Restrictive or infiltrative cardiomyopathy
7 Diffuse coronary artery disease
20
Q

Tall QRS

5

Study These Flashcards
A 
1 LVH 
2 Hypertrophic cardiomyopathy
3 LBBB 
4 Wolff-Parkinson White pattern 
5 Normal persons with thin body habitus
21
Q

Prominent R wave in lead V1

7

Study These Flashcards
A

1 RVH
2 Posterior wall MI
3 Incorrect lead placement: Electrode for lead V1 placed in 3rd instead of 4th intercostal space
4 Skeletal deformities (e.g., pectus excavatum)
5 RBBB
6 Wolff-Parkinson-White pattern
7 Duchenne’s muscular dystrophy

22
Q

Left axis deviation

Study These Flashcards
A
  • Left anterior fascicular block (if axis > -45°, item 45)
  • Inferior wall MI (items 57, 58)
  • LBBB (item 47)
  • LVH (item 40)
  • Ostium primum ASD (item 79)
  • Chronic lung disease (item 81)
  • Hyperkalemia (item 74)
23
Q

Right axis deviation

Study These Flashcards
A
  • RVH (item 41)
  • Vertical heart
  • Chronic lung disease (item 81)
  • Pulmonary embolus (item 82)
  • Left posterior fascicular block (item 46)
  • Lateral wall MI (items 55, 56)
  • Dextrocardia (item 80)
  • Lead reversal (item 03)
  • Ostium secundum ASD (item 78)
24
Q

Q wave myocardial infarction

Study These Flashcards
A

(see items 51-60)
• Anterolateral MI: Abnormal Q waves in leads V4-V6
• Anterior MI: Abnormal Q waves in at least two consecutive
leads in V2-V4
• Anteroseptal MI: Abnormal Q waves in leads V1-V3 (and
sometimes V4)
• Lateral MI: Abnormal Q waves in leads I and aVL
• Inferior MI: Abnormal Q waves in at least two of leads II, III,
and aVF

25
Pseudoinfarcts (Q waves in absence of MI)
• Wolff-Parkinson-White (item 34): Negative delta waves mimic Q waves • Hypertrophic cardiomyopathy (item 85): Q waves in I, aVL, V4-V6 due to septal hypertrophy • LVH (item 40): Poor R wave progression, at times with ST elevation in V1-V3, can mimic anteroseptal MI. Inferior Q waves may be present and can mimic inferior MI • LBBB (item 47): QS pattern in V1-V4mimics anteroseptal MI. Less commonly, Q waves in III and aVF mimic inferior MI • RVH (item 41) • Left anterior fascicular block (item 46) • Chronic lung disease (item 81): Q waves appear in inferior and/or right and mid-precordial leads • Amyloid, sarcoid, and other infiltrative cardiomyopathic diseases: Electrically active tissue replaced by inert substance • Cardiomyopathy • Chest deformity (e.g., pectus excavatum) • Pulmonary embolism (item 82): Q wave in lead III and sometimes aVF, but Q waves in II are rare • Myocarditis • Myocardial tumors • Hyperkalemia (item 74) • Pneumothorax: QS complex in right precordial leads • Pancreatitis • Lead reversal (item 03) • Corrected transposition • Muscular dystrophy • Mitral valve prolapse: Rare Q wave in III and aVF • Myocardial contusion: Q waves in areas of intramyocardial hemorrhage and edema • Left/right atrial enlargement: Prominent atrial repolarization wave (Ta) can depress the PR segment and mimic Q waves • Atrial flutter (item 18): Flutter waves may deform the PR segment and simulate Q waves • Dextrocardia (item 80)
26
Early R wave progression (tall R wave in V1, V2; R/S > 1)
* RVH (item 41) * Posterior MI (items 59, 60) * RBBB (item 43) * Wolff-Parkinson-White pattern (item 34) * Normals * Duchenne’s muscular dystrophy
27
Poor R wave progression (first precordial lead where R | wave amplitude
* Normals (abnormal lead placement) * Anterior or anteroseptal MI (items 53, 54) * Dilated or hypertrophic cardiomyopathy * LVH (item 40) * Chronic lung disease (item 81) * Cor pulmonale (item 82) * RVH (item 41) * Left anterior fascicular block (item 45)
28
Reverse R wave progression (decreasing R wave | amplitude across precordial leads)
* Anterior MI (items 53, 54) | * Dextrocardia (item 80)
29
Initial slurring of R wave (delta wave)
• Wolff-Parkinson-White pattern (item 34)
30
Terminal notching (of R or S wave)
• Hypothermia (Osborne wave; item 88) • Early repolarization (item 61) • Pacemaker spike (failure to sense; item 94) • Atrial flutter (item 18): Flutter waves may be superimposed on QRS
31
ST segment elevation
• Myocardial injury (item 65): Convex upward ST elevation localized to a few leads and terminates with an inverted T (unless hyperacute peaked T wave). Reciprocal ST depression evident in other leads. Q waves frequently present. ST & T wave changes evolve, and T wave becomes inverted before ST segment returns to baseline • Acute pericarditis (item 84): Widespread ST elevation (I-III, aVF, V3-V6) without reciprocal ST depression in other leads except aVR. No Q wave. PR segment depression is sometimes present. ST-T wave changes evolve; T wave often becomes inverted after ST segment returns to baseline. Note: Pericarditis (and ST elevation) may be focal • Ventricular aneurysm: ST elevation usually with deep Q wave or QS in same leads; ST & T wave changes persist and are stable over a long period of time • Early repolarization (item 61): Concave upward ST elevation that ends with an upward T wave, with notching on the downstroke of the R wave. T waves are usually large and symmetrical. ST-T wave changes are stable over a long time period • LVH (item 40) • Bundle branch block (items 43, 47) • Central nervous system disease (item 86) • Apical hypertrophic cardiomyopathy (item 85) • Hyperkalemia (item 74) • Acute cor pulmonale (item 82) • Myocarditis • Myocardial tumor
32
ST segment depression
• Myocardial ischemia (item 64): horizontal or downsloping • Repolarization changes secondary to ventricular hypertrophy (item 67) or bundle branch block (items 43, 47) • Digitalis effect (item 70) • “Pseudodepression” due to superimposition of atrial flutter waves or prominent atrial repolarization wave (as seen with atrial enlargement, pericarditis, atrial infarction) on the ST segment • Central nervous system disorder (item 86) • Hypokalemia (item 75) • Antiarrhythmic drug effect (item 72) • Mitral valve prolapse
33
Nonspecific ST segment changes
* Organic heart disease * Drugs (e.g., quinidine) * Electrolyte disorders (e.g., hypokalemia, item 75) * Hyperventilation * Myxedema (item 87) * Stress * Pancreatitis * Pericarditis (item 84) * Central nervous system disorders (item 86) * LVH (item 40) * RVH (item 41) * Bundle branch block (items 43, 44, 47, 48) * Healthy adults (normal variant) (item 02)
34
Tall peaked T waves
• Hyperacute MI • Angina pectoris • Normal variant (item 02): Usually effects mid-precordial leads • Hyperkalemia (item 74): More common when the rise in serum potassium is acute • Intracranial bleeding (item 86) • LVH (item 40) • RVH (item 41) • LBBB (item 47) • Superimposed P wave from APC, sinus rhythm with marked first-degree AV block, complete heart block, etc. • Anemia
35
Deeply inverted T waves
* Myocardial ischemia (item 64) * LVH (items 40, 67) * RVH (items 41, 67) * Central nervous system disorder (item 86) * Wolff-Parkinson-White pattern (item 34)
36
Nonspecific T waves
• Persistent juvenile pattern: T wave inversion in V1-V3 in young adults • Organic heart disease • Drugs (e.g., quinidine) • Electrolyte disorders (e.g., hypokalemia, item 75) • Hyperventilation • Myxedema (item 87) • Stress • Pancreatitis • Pericarditis (item 84) • Central nervous system disorders (item 86) • LVH (item 40) • RVH (item 41) • Bundle branch block (items 43, 44, 47, 48) • Healthy adults (normal variant) (item 02)
37
Long QT interval -- Acquired conditions
``` • Drugs (quinidine, procainamide, disopyramide, amiodarone, sotalol, dofetilide, azimilide, phenothiazines, tricyclics, lithium) • Hypomagnesemia • Hypocalcemia (item 77) • Marked bradyarrhythmias • Intracranial hemorrhage (item 86) • Myocarditis • Mitral valve prolapse • Myxedema (item 87) • Hypothermia (item 88) • Liquid protein diets ```
38
Long QT interval -- Congenital disorders
* Romano-Ward syndrome (normal hearing) | * Jervell and Lange-Nielson syndrome (deafness)
39
Short QT interval
* Hypercalcemia (item 76) * Hyperkalemia (item 74) * Digitalis effect (item 70) * Acidosis * Vagal stimulation * Hyperthyroidism * Hyperthermia
40
Prominent U wave
* Hypokalemia (item 75) * Bradyarrhythmias * Hypothermia (item 88) * LVH (item 40) * Coronary artery disease * Drugs (digitalis, quinidine, amiodarone, isoproterenol)
41
Inverted U wave
* LVH (item 40) * Severe RVH (item 41) * Myocardial ischemia
42
Right axis deviation is associated with which conditions?
- Chronic lung disease (e.g. emphysema) - RVH - Lateral wall MI - Dextrocardia - Vertical heart - PE - Ostium secundum ASD - Left posterior fascicular block

Cardiology (12 decks)

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