ECG Interpretation Flashcards Preview

Clinical Medicine LAB - Professor Sample > ECG Interpretation > Flashcards

Flashcards in ECG Interpretation Deck (45)
Loading flashcards...
1
Q

Axis gives us the _________ of depolarization?

A

direction

2
Q

The progressive depolarization of the __________ moves in a certain direction.

A

myocardium

AV node is the tail of the vector

3
Q

Positive wave of depolarization is moving ______ a positive electrode, an ______ deflection.

A

toward

upward

4
Q

What does a vector show?

A

the generalized direction of depolarization of the heart

5
Q

Vector normally points down to between _ and ___ degrees.

A

0 and +90 degrees

6
Q

When the left ventricle is thickened as in LVH then the vector ( wave of depolarization) will have a ______ deflection to the ____.

A

bigger
left

horizontal axis

7
Q

Vectors swing ____ from damaged heart?

A

away

8
Q

Mean QRS Vector?

A

AV node is the tail of the vector

To determine the axis:
use leads I and AVF

9
Q

To determine the axis of the QRS vector use what leads?

A

I and AVF

10
Q

QRS deflection of:
Lead 1: positive
AVF: positive

what is the resulting axis?

A

Normal

11
Q

QRS deflection of:
Lead 1: positive
AVF: negative

what is the resulting axis?

A

LAD

left axis deviation

12
Q

QRS deflection of:
Lead 1: negative
AVF: positive

what is the resulting axis?

A

RAD

Right axis deviation

13
Q

QRS deflection of:
Lead 1: negative
AVF: negative

what is the resulting axis?

A

Extreme RAD or Extreme LAD

14
Q

What can cause an extreme RAD or extreme LAD?

A

Extreme RAD: severe pulmonary HTN, severe RSHF, severe COPD

Emphysema
Hyperkalemia
Lead transposition
Ventricular pacing
Ventricular arrhythmia
15
Q

What can cause a LAD?

A

HTN
Valvular disease

Past inferior MI
left anterior fascicular block
Ventricular pacing
Emphysema
Hyperkalemia
WPW- right sided accessory pathway
Tricuspid atresia
Ostium primum atrial septum defect
16
Q

What can cause a RAD?

A

Past MI on the left
RVH
Pulmonary HTN
PE

Normal in kids
LVH
COPD
previous anterolateral MI
PE
ASD or VSD
Dextrocardia
Pectus excavatum
WPW - left sided accessory pathway
Left posterior fascicular block
reversed arm leads
17
Q

If LVH, what will you see in lead II?

A

Bifid P wave with > 40 ms between the two peaks

Total P wave duration > 110 ms

18
Q

If LVH, what will you see in V1?

A

Biphasic P wave with terminal negative portion > 40 ms duration

Biphasic P wave with terminal negative portion > 1mm deep

one side has a stronger vector or wave of depolarization -

19
Q

Right atrial enlargement (RAH) produces a peaked _ wave with amplitude: > ___ mm in the inferior leads (II, III, AVF) and > ___ mm in V1 and V2

A

P wave ( P pulmonale)

> 2.5 mm in inferior leads

> 1.5 mm in V1 and V2

V1 sits right above the right atrium so we get a big upward deflection in V1 with RAH

20
Q

If RVH, V1 will show?

A

Large R wave

Small S wave

21
Q

If LVH, V1 will show?

A

Deep S wave

22
Q

If LVH, V5 will show?

A

Tall R wave

23
Q

LVH, Sokolov-Lyon criteria?

A

S wave depth in V1 + tallest R wave height in V5-V6 > 35 mm.

24
Q

What is ischemia (MI) and what is it characterized by on ECG

A

Reduced blood supply causing hypoxia

Characterized by inverted T waves

inverted T wave from an area in the heart that is not getting oxygen

25
Q

If we are having an acute infarct ( happening now) what will we see on the ECG?

A

ST segment elevation:
>1mm in limb leads
> 2mm in 2 continguous precordial leads

26
Q

What are reciprocal changes with MI injury?

A

St depression in other leads on the other side of the heart. because the vector is swinging

Ex.

2, 3, avf - inferior part of the heart ( inferior leads) - ST elevation

then…..

st depression in 1 and avl ( lateral leads) - this is the reciprocal change

27
Q

With an Mi, what indicated necrosis on ECG?

A

Q wave indicates necrosis

Significant Q wave is 1 mm wide or 1/3 of the QRS amplitude

q waves are pathologic and indicated necrosis

28
Q

Area of ECG changes correlates with area of ischemia: Anterior?

A

V1-V4

29
Q

Area of ECG changes correlates with area of ischemia: Anteroseptal?

A

V1 and V2

30
Q

Area of ECG changes correlates with area of ischemia: Anterolateral ?

A

V3 and V4

31
Q

Area of ECG changes correlates with area of ischemia: Lateral?

A

I and AVL

32
Q

Area of ECG changes correlates with area of ischemia: Inferior?

A

II, III, AVF

33
Q

Area of ECG changes correlates with area of ischemia: Posterior?

A

Large R wave or ST depression in V1/V2

posterior MI are very hard to see on an EKG - cardiac enzymes for better determination

34
Q

Area of ECG changes correlates with area of ischemia: Subendocardial?

A

Infarction that doesn’t extend through entire LV wall, flattened ST segments.

35
Q

Brugada Syndrome is?

A

Familial condition caused by dysfunctional cardiac Na+ channels.

36
Q

Brugada Syndrome findings on ECG

A

RBBB and ST elevation in leads V1-V3

ST segment convex to the top
ST segment downward straight

37
Q

Pericarditis ECG findings?

A

Elevated the entire T wave from baseline

Produces elevated ST segments

it is the way the vector is going through the inflamed tissue

ST elevation in all of the leads

38
Q

Pulmonary Embolism ECG findings?

A

S1Q3T3:
Large wide S in I
Large Q in III
Inverted T in III

Sinus Tachycardia is the most common finding on a EKG with a PE

39
Q

COPD ECG finding?

A

Low voltage amplitude in all leads

RAD

barrel chested and a small heart ( small heart in a large chest )

“all the leads with kind of dampen”

40
Q

Hyperkalemia ECG finding?

A

P wave flattens ( >9.0 mEq/L)
QRS widens (>7.5)
Peak T waves( >6.0)

electrolyte disturbances

elevated potassium levels - peaked T waves = because K is used in repolarization which is happening during a T wave

41
Q

Hypokalemia ECG findings?

A

T wave flattened
U wave develops
At risk for Torsades

“Tiny bumps after a QRS complex“

lower and lower the K then the wider and wider the QRS

42
Q

Hypocalcemia ECG findings?

A

QT interval lengthens (Torsades risk)

43
Q

Hypercalcemia ECG findings?

A

QT interval shortens

44
Q

Digitalis Effects on ECG finding?

A

Gradual downward curve of the ST segment

“Reverse check” or “Reverse tick” signs from digoxin effect

45
Q

Pacemaker ECG findings?

A

Can see pacing “spike” on ECG

first spike is atria depolarization second is ventricularr