8/4- Basics of ECG: Bridging Theory and Practice Flashcards Preview

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Flashcards in 8/4- Basics of ECG: Bridging Theory and Practice Deck (30):
1

Which ECG limb lead has a negative QRS complex in normal subjects?

A. Lead I

B. Lead II

C. Lead aVF

D. Lead aVR

E. Lead aVL

Which ECG limb lead has a negative QRS complex in normal subjects?

A. Lead I

B. Lead II

C. Lead aVF

D. Lead aVR

E. Lead aVL

2

Which chest leads are most aligned with overall position of heart in chest cavity?

A. V1/V2

B. V3/V4

C. V5/V6

Which chest leads are most aligned with overall position of heart in chest cavity?

A. V1/V2

B. V3/V4

C. V5/V6

3

Which chest leads have consistently positive QRS complexes?

A. V1/V2 "septal leads"

B. V3/V4 "anterior leads"

C. V5/V6 "lateral heads"

Which chest leads have consistently positive QRS complexes?

A. V1/V2 "septal leads"* 

B. V3/V4 "anterior leads"

C. V5/V6 "lateral heads"

4

Where is the sinus node located?

A. Right atrium near SVC

B. Right atrium near IVC

C. Left atrium near pulmonary veins

Where is the sinus node located?

A. Right atrium near SVC

B. Right atrium near IVC

C. Left atrium near pulmonary veins

5

What is a normal QRS axis?

A. -30 to +90 degrees in the frontal plane

B. 0 to + 90 degrees in the frontal plane

C. -30 to -90 degrees in the frontal plane

What is a normal QRS axis?

A. -30 to +90 degrees in the frontal plane 

B. 0 to + 90 degrees in the frontal plane

C. -30 to -90 degrees in the frontal plane

6

Describe (broadly) the normal QRS axis?

Downward and to the left (-30 to +90)

- QRS is positive in Leads I and aVF

7

What planes are used in placing ECG leads? Number/type of leads?

Frontal plane:

- 3 standard limb leads: bipolar leads I, II, III

- 3 augmented limb leads: aVF, aVR, aVL

Horizontal plane:

- 6 precordial chest leads

8

What is Einthoven's triangle?

3 electrodes: RA, LA, LL

- generate 3 bipolar limb leads I, II, and III

Lead 1: bipolar vector from R arm to L arm

Lead 2: R arm to L leg

Lead 3: L arm to L leg

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9

What is the setup for the augmented limb leads?

Augmented limb leads: aVR, aVL, and aVF use combination of electrodes as ground (vector looks like it's coming from the other two)

aVR: ground L arm, L leg

aVL: ground R arm, L leg

aVF: ground R arm, L arm

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10

How far apart are the vectors for the 3 bipolar leads?

60 degrees (0, 60, and 120) 

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11

How far apart are the vectors for the 3 augmented leads?

120 degrees (-150, -30, and 90) 

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12

Which vectors point downward?

Another name for them?

What do they reflect?

"Inferior leads"; inflect pathology in the inferior wall of the left ventricle

Leads: II, III, aVF 

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13

How do we group limb leads (broad groups)?

Inferior leads: II, III, aVF

Lateral leads: I and aVL

14

What do inferior leads reflect? Where do they point?

- Point inferiorly

- Reflect inferior LV wall pathology (e.g. ischemia or infarction)

15

What do superior leads reflect? Where do they point?

- Point laterally

- Reflect lateral LV wall pathology

16

Which lead(s) do(es) not have a positive QRS complex? Why?

aVR

- All standard ECG leads have a positive QRS except aVR

- The aVR vector points upward and to the right, while the heart is on the left side, pointing downward 

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17

Where are the precordial chest leads placed?

???

V1-

V2-

V3-

V4-

V5-

V6- 

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18

How do we group chest/precordial leads?

Chest leads V1-V6 derived from + chest electrodes placed over chest wall

V1, V2: septal (or anteroseptal) leads

V3, V4: anterior leads

V5, V6: lateral leads

19

QRS is negative in leads ___ and positive in ___

QRS is negative in leads V1/V2 and positive in V5/V6

As you move from V1 to V6, the leads are becoming more positive/upright (V1 pointing out to the right, while others fan across until V6 is pointing left and most aligned with the heart in the chest cavity) 

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20

T/F: V5 and V6 are better aligned with the chest orientation in the chest and are thus "positive"?

True 

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21

Draw/label normal EKG (P, QRS, T) wave?

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22

Sequence of depolarization in the heart?

- Sinus node

- AV node

- His bundle

- Bundle branches

- Purkinje fibers

- Myocardium 

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23

Cardiac structures and the corresponding ECG waves:

- Sinus node:

- AV node:

- His bundle:

- Bundle branches:

- Purkinje fibers:

- Myocardium

Cardiac structures and the corresponding ECG waves:

- Sinus node: P wave

- AV node: PR interval

- His bundle: PR interval

- Bundle branches: QRS interval

- Purkinje fibers: QRS interval

- Myocardium: QRS interval

24

Localization of ECG abnormalities:

- Abnormal P wave

- Long PR interval

- Short PR interval

- Wide QRS interval

Localization of ECG abnormalities:

- Abnormal P wave: ectopic atrial rhythm

- Long PR interval: AV block

- Short PR interval: accessory tract

- Wide QRS interval: bundle branch block or dilated ventricles

25

What is the QRS axis? Direction?

The QRS axis is the overall direction of ventricular depolarization

- Ventricular depolarization proceeds from the right and left bundle branches and outward from ENDOcardium to EPIcardium

- It proceeds downward and to the left in the frontal plane 

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26

How can a normal heart vector be up to 0 to -30 if the heart points down and to the left?

Left ventricle may undergo concentric hypertrophy in response to high blood pressure, causing the heart axis to shift leftward

27

What is commonly seen in the EKG of individuals over the age of 50 or 60?

This leftward deviation/shift of the heart axis

28

The indeterminate axis/area is where?

- 90 to +/- 180

29

Deviation:

- Normal:

- Left:

- Right:

- Indeterminate:

Deviation:

- Normal: -30 to +90

- Left: -30 to -90

- Right: +90 to 180

- Indeterminate: -90 to 180 

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30

Axis shift is typically important as a marker of what?

Ventricular hypertrophy

(Left hypertrophy -> left deviation and vice versa)