EKG lecture 3 pt 1

Question 1

List the 9 steps of EKG analysis

Answer 1

Heart Rate
Intervals – PR, QT, QRS duration
Axis
Rhythm – 4 questions
Conduction blocks
Preexcitation
Enlargement and hypertrophy
CAD
Other

Question 2

List the 4 questions about rhythm

Answer 2

Are normal P waves present?
Are QRS complex narrow or wide?
What is the Relationship of P waves & QRS complexes?
Is the rhythm regular or irregular?

Question 3

List 2 kinds of conduction blocks

Answer 3

AV blocks
BBB or hemiblocks

Question 4

Define hypertrophy & what usually causes it

Answer 4

Increase in muscle mass
Usually due to pressure overload (afterload)

Question 5

Define enlargement and what it’s usually due to

Answer 5

Dilation of chamber
Usually due to volume overload (preload)

Question 6

1) What is defined as an increase in muscle mass?
2) What are 2 common causes of LVH?

Answer 6

1) Hypertrophy?
2) HTN + AS
(LVH = left ventricular hypertrophy)

Question 7

1) What is defined as dilation of a chamber?
2) What are 2 causes of this?

Answer 7

1) Enlargement
2) AR =LVE
Mr = LAE

Question 8

1) __________ regurgitation causes left ventricular enlargement
2) ___________ regurgitation causes left atrial enlargement

Answer 8

1) Aortic
2) Mitral

Question 9

True or false: enlargement and hypertrophy freq. occur together, and can be pathologic or compensatory

Answer 9

True

Question 10

What are 2 characteristics of hypertrophied muscle?

Answer 10

Required increased metabolic needs – oxygen to fuel the bigger muscle mass
Decreased capillary density - at risk for ischemia in pathologic hypertrophy

Question 11

True or false: EKG poor @ distinguishing between hypertrophy and enlargement (TTE is much better)

Answer 11

True

Question 12

What do enlargement and hypertrophy often refer to?

Answer 12

Often refer to “Atrial Enlargement” and “Ventricular Hypertrophy”

Question 13

1) What can you use the P wave to evaluate?
2) What abt the QRS complex?

Answer 13

1) Atrial enlargement
2) Ventricular hypertrophy

Question 14

True or false: EKG changes cannot occur with hypertrophy or enlargement

Answer 14

False; EKG changes may occur with hypertrophy or enlargement

Question 15

What 3 EKG changes may occur with hypertrophy or enlargement?

Answer 15

1. Increased duration of wave
2. Increased amplitude of wave
3. Shift in average electrical vector called mean electrical axis or just AXIS
   -P wave, QRS, T wave

Question 16

What does the mean electrical axis show?

Answer 16

Ventricular depolarization

Question 17

Define average vector

Answer 17

Mean Vector

Question 18

Each successive vector during depolarization: Septal depolarization starts and each ensuing vector swings ___________

Answer 18

leftward

Question 19

1) Give a quick estimate of the axis +90 to 0 degrees
2) Give a quick estimate of the axis +90 to -30 degrees

Answer 19

1) Lead I and aVF QRS is positive = normal axis
2) If lead aVF QRS negative, & leads I & II positive = normal axis

Question 20

How do you define the axis more precisely?

Answer 20

Look for the lead with biphasic QRS; axis must be perpendicular to this lead

Question 21

What would aVF and lead 1 show in right axis deviation?

Answer 21

Negative in lead 1, positive in aVF

Question 22

What does it tell you if lead 1 is positive?

Answer 22

Axis is toward the right (lower left on circle)

Question 23

What direction is extreme right axis deviation?

Answer 23

Arrow pointing up and left

Question 24

What does it tell you if lead I and lead aVF are both negative?

Answer 24

Extreme right axis deviation

Question 25

Elderly patient with dyspnea and BP 190/115; what eventually happens to the heart?

Answer 25

??? didn't hear him

Question 26

slide 22

Answer 26

Increase afterload = Increased work of LV Leads to Left Ventricular Hypertrophy (LVH) Left axis deviation (LAD) on EKG – what would this look like on EKG? CXR?

Question 27

Right axis deviation (RAD): 1) What does it result from? 2) How common is it? 3) What results from this?

Answer 27

1) Results from right ventricular hypertrophy (RVH) to extent that it dominates the LV (rare) 2) Less common than LVH 3) Massive change to overcome LV affect on axis

Question 28

Normal P wave: 1) What is normal duration? 2) What is normal amplitude? 3) What does the first part of the P wave show? 4) What does the second part show?

Answer 28

1) Duration: < 0.12 sec duration (3 small boxes) 2) Amplitude: should not exceed 2.5 mm (.25 mV) 3) Right atrial depole 4) Left atrial depole