Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ABIM > EKG-Interpretation > Flashcards

EKG-Interpretation Flashcards

1
Q

Interpretation sequence (Short)

A

Rate Rhythm Axis Intervals Waveforms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Each small box, Each big box

A

Small box = 0.04 secs Big box = 0.2 secs 40 msecs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Rate calculation

A

Number of QRS complexes x 6 For slow or irregular rhythms: Rate=number of complexes on the rhythm strip x 6 (this gives the average rate over a ten-second period).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Bradycardia

A

HR <60

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Tachycardia

A

HR > 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

1 second

A

5 big boxes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Rhythm interpretation framework (short)

A

Fast or slow or normal? Regular or irregular? Ventricular or supraventricular?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Normal axis is between _ to _ degrees.

A

-30 to 90 degrees Leftward axis, between 0° and up to −30°, is “borderline” ?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Lead _ is at 0 degrees

A

Lead I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Lead _ is at 60 degrees

A

Lead II

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Lead _ is at 90 degrees

A

aVF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Lead _ is at 120 degrees

A

III

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Lead _ is at -150 degrees

A

aVR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why is it most efficient to estimate axis is to look at the QRS complexes in leads I and aVF?

A

Leads I and aVF are 90 degrees apart. Explanation: Most of normal axis (-30 to 90) is between 0 to 90. The combination of directions of QRS complexes makes it easy to figure out if axis is normal with one exception: when the axis is between the narrow sliver 0 to -30 which is still normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Lead I is positive, Lead aVF is positive. What is the axis?

A

Normal (0 to 90)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Lead I is positive, Lead aVF is negative. Is this left axis deviation?

A

Not necessarily. This is possible LAD Is lead II positive? Yes -> Normal (0 to -30 degrees) No -> LAD (-30 to -90 degrees)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Lead I is negative. Lead aVF is positive. The axis is:

A

Right axis deviation Explanation: RAD (+90 to 180 degrees)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Lead I is negative and Lead aVF is negative. The axis:

A

Extreme Axis Deviation (-90 to 180 degrees)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Causes: left axis deviation

A

Normal variation LVH LBB LAFB Inferior MI Hyperkalemia Ventricular pacing /ectopy Pre-excitation Syndromes Primum ASD Comments: - Left anterior fascicular block – diagnosis of exclusion - Mechanical shifts from pregnancy, ascites , short, squat patient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Common causes: RAD

A

Normal Chronic lung disease Acute RV strain LPFB RVH Comment: - Normal variation: tall thin patients with a vertically oriented heart - COPD causes RBB due to mechanical shift Acute RV strain: think of pulmonary embolism RVH - right ventricular hypertrophy, uncommon Left posterior fascicular block – diagnosis of exclusion Lateral MI - rare

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Causes: extreme axis deviation

A

Ventricular rhythms: VT, AIVR, ventricular ectopy Hyperkalaemia Severe right ventricular hypertrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

In LAD, the axis is rotated clockwise/anticlockwise

A

Anticlockwise

23
Q

In RAD, the axis is rotated clockwise/anticlockwise

A

Clockwise

24
Q

PR interval starts at _ and ends at _.

A

PR interval starts at the beginning of the P wave and ends at the beginning of the QRS complex.

25
Q

QRS start at and ends at _ and ends at _.

A

Begins at the start of the first QRS deflection, ends at the start of the ST isoelectric segment.

26
Q

The ST segment is the isoelectric section of the ECG between the end of the _ wave (the J point) and the beginning of the _ wave.

A

The ST segment is the isoelectric section of the ECG between the end of the S wave (the J point) and the beginning of the T wave.

27
Q

What is the J point?

A

The start of the ST segment: end of the S wave.

28
Q

PR segment reflects conduction through the __ node.

A

AV

29
Q

What is the difference between the PR segment and the PR interval?

A

PR interval = P wave + PR segment

30
Q

PR interval is between __ to __ ms (_ to _ small squares).

A

120 to 200 ms duration (3 to 5 small squares).

31
Q

First degree heart block: PR > ___ ms, .

A

200

32
Q

PR interval < 120 ms suggests ____ or __ rhythm.

A
  • pre-excitation - junctional Explanation: PR interval < 120 ms suggests pre-excitation (the presence of an accessory pathway between the atria and ventricles) or AV nodal (junctional) rhythm.
33
Q

The rhythm is best analysed on a 12 lead ECG is a 10 second recording from Lead _.

A

II

34
Q

Rhythm analysis framework (long)

A

Rate: fast | slow Regularity of QRS: regular | irregular QRS morphology: narrow | wide P: absent | present P and QRS : associated or disassociated Onset: abrupt or gradual Vagal manoeuvre response: slowing, abruptly terminates, no response

35
Q

Narrow complex QRS implies: __, __ or -__ origin.

A

Narrow complex QRS suggests: sinus, atrial or junctional origin. Important

36
Q

Wide complex QRS implies __ origin, or __ with __.

A

Wide complex QRS implies ventricular origin, or supraventricular with aberrancy.

37
Q

Causes: Absent P wave

A

sinus arrest, atrial fibrillation

38
Q

Abrupt onset of an arrhythmia suggests __ process.

A

re-entrant Explanation: Abrupt onset of an arrhythmia suggests re-entrant process.

39
Q

Gradual onset of an arrhythmia suggests increased ___.

A

automaticity Gradual onset of an arrhythmia suggests increased automaticity.

40
Q

Difference between segment and interval,

A

Electrocardiographic Segment: : Line (usually isoelectric) that connects two waves without including either one of them. Electrocardiographic interval: Portion of the EKG (ECG) that includes a segment and one or more waves.

41
Q

What does the QT interval represent?

A

The QT interval represents electrical depolarization and repolarization of the ventricles.

42
Q

Right Axis Deviation: Uncommon causes

A

WPW syndrome Lateral STEMI Sodium-channel blockade, e.g. TCA poisoning Dextrocardia Ventricular ectopy Secundum ASD – rSR’ pattern

43
Q

Concordant CXR finding

A

Cardiomegaly

Pericardial effusion leading low voltage QRS and electrical alternans

44
Q

Electrical alternans: best seen in?

A

Lead II

45
Q

SI QIII TIII pattern: Sensitivity for PE

A

20%

deep S wave in lead I, Q wave in III, inverted T wave in III.

Neither sensitive nor specific for pulmonary embolism; found in only 20% of patients with PE.

Sinus tachycardia – the most common abnormality; seen in 44% of patients.

Complete or incomplete RBBB – associated with increased mortality; seen in 18% of patients.

Right ventricular strain pattern – T wave inversions in the right precordial leads (V1-4) ± the inferior leads (II, III, aVF). This pattern is seen in up to 34% of patients and is associated with high pulmonary artery pressures.

Right axis deviation – seen in 16% of patients. Extreme right axis deviation may occur, with axis between zero and -90 degrees, giving the appearance of left axis deviation (“pseudo left axis”).

Dominant R wave in V1 – a manifestation of acute right ventricular dilatation.

Right atrial enlargement (P pulmonale) – peaked P wave in lead II > 2.5 mm in height. Seen in 9% of patients.

SI QIII TIII pattern – deep S wave in lead I, Q wave in III, inverted T wave in III. This “classic” finding is neither sensitive nor specific for pulmonary embolism; found in only 20% of patients with PE.

Clockwise rotation – shift of the R/S transition point towards V6 with a persistent S wave in V6 (“pulmonary disease pattern”), implying rotation of the heart due to right ventricular dilatation.

Atrial tachyarrhythmias – AF, flutter, atrial tachycardia. Seen in 8% of patients.

Non-specific ST segment and T wave changes, including ST elevation and depression. Reported in up to 50% of patients with PE.

lifeinthefastlane.com

46
Q

RV infarction: describe features

A

ST-segment elevation in leads II, III, aVF, and V1

A 61-year-old man with a personal history of smoking and a family history of coronary artery disease presented with what he described as a squeezing pain in the left side of his chest that woke him from sleep. He also had associated dizziness and diaphoresis. His heart rate was 85 beats per minute, and he was hypotensive (blood pressure, 90/60 mm Hg). An initial electrocardiogram (ECG) showed a normal sinus rhythm, with ST-segment elevation in leads II, III, aVF, and V1 (Panel A). Right ventricular infarction was suspected because of ST-segment elevation in V1. ECG with precordial leads on the right side was performed and showed 2:1 atrioventricular block and ST-segment elevation in leads rV3 through rV6, which confirmed ST-segment elevation myocardial infarction of the inferior wall, with involvement of the right ventricle (Panel B). Intravenous fluids were administered, and a temporary transvenous pacing wire was placed. Coronary angiography revealed a right coronary artery with 100% occlusion proximal to the right ventricular branch (Panel C, arrow). Percutaneous coronary intervention was performed, and flow to the right coronary artery (Panel D, black arrow) and the right ventricular branch (Panel D, white arrow) was restored. With adequate fluid resuscitation and the restoration of flow in the blocked artery, the patient’s hemodynamic status improved, and the temporary pacing wire was removed the next day. Subsequent echocardiography revealed normal left ventricular systolic function and mild right ventricular dysfunction.

47
Q

Palpitations, pre-syncope+hypotension

Describe EKG features

20-year old female presenting with palpitations and presyncope, BP 75/50.

A
  1. Irregularly irregular broad complex tachycardia.
  2. Extremely rapid ventricular rates — up to 300 bpm in places (RR intervals as short as 200ms or 1 large square).
  3. Beat-to-beat variability in the QRS morphology, with subtle variation in QRS width.
  4. Explanation of ECG Findings:

Irregularly irregular rhythm is consistent with atrial fibrillation.

There is a left bundle branch block morphology to the QRS complexes.

However, the ventricular rate is far too rapid for this to be simply AF with LBBB.

The rates of 250-300 bpm and the variability in QRS complex morphology indicate the existence of an accessory pathway between the atria and ventricles.

Diagnosis:

These findings indicate atrial fibrillation in the context of Wolff-Parkinson-White syndrome.

48
Q

Why is this not atrial fibrillation with LBB?

A

ventricular rate is far too rapid for this to be simply AF with LBBB.

Main Abnormalities:

Irregularly irregular broad complex tachycardia.

Extremely rapid ventricular rates — up to 300 bpm in places (RR intervals as short as 200ms or 1 large square).

Beat-to-beat variability in the QRS morphology, with subtle variation in QRS width.

Explanation of ECG Findings:

Irregularly irregular rhythm is consistent with atrial fibrillation.

There is a left bundle branch block morphology to the QRS complexes.

However, the ventricular rate is far too rapid for this to be simply AF with LBBB.

The rates of 250-300 bpm and the variability in QRS complex morphology indicate the existence of an accessory pathway between the atria and ventricles.

Diagnosis:

These findings indicate atrial fibrillation in the context of Wolff-Parkinson-White syndrome.

49
Q

Bradycardia: describe features

Middle-aged diabetic patient presenting with shortness of breath. Clinical evidence of pulmonary oedema. Describe the ECG

A

Hyperkalemia

Main Abnormal Findings

  1. Severe bradycardia of 36 bpm.
  2. Rhythm is difficult to ascertain — appears irregular (?slow AF) although there are some small-voltage P waves seen in V1-2.
  3. Broad QRS complexes with an atypical LBBB morphology.
  4. Subtle symmetrical peaking (“tenting”) of the T waves in V2-5.

Diagnosis

The combination of bradycardia, flattening and loss of P waves, QRS broadening and T wave abnormalities is highly suspicious for severe hyperkalaemia. This patient had a potassium of 8.0 in the context of anuric renal failure.

50
Q

Tachycardia:

20 year old male presenting with seizures. BP 80/50. Describe the ECG.

A

TCA poisoning

  1. Broad complex tachycardia, rate ~ 130 bpm.
  2. The rhythm is likely sinus tachycardia with a 1st degree AV block — note the “camel hump” appearance to the T waves indicating a hidden P wave.
  3. Interventricular conduction delay (QRS duration > 100ms, not typical LBBB / RBBB morphology)
  4. Right axis deviation.
  5. Secondary R’ wave in aVR > 3 mm.

Diagnosis

In the context of a patient presenting with seizures and hypotension, the combination of…

QRS broadening > 100 ms

R’ wave in aVR > 3 mm

… is highly suggestive of poisoning with a sodium-channel blocking agent — e.g. tricyclic antidepressant.

The sinus tachycardia may be due to the anticholinergic effects of the TCA.

51
Q

Which coronary artery is involved?

A

Anterolateral STEMI

  1. ST elevation in V2-6, I and aVL
  2. Reciprocal ST depression in III and aVF
  3. Pathological Q waves in V2-3
  4. Hyperacute T waves in V2-4
  5. This pattern of changes in consistent with acute occlusion of the left anterior descending artery.
52
Q

T wave abnormalities: camel hump

Causes of this appearance

A

Hidden P waves in sinus tachycardia

  1. Prominent U waves fused to the end of the T wave, as seen in severe hypokalaemia
  2. Hidden P waves embedded in the T wave, as seen in sinus tachycardia and various types of heart block
53
Q
A

ABIM (36 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions