EKG

Question 1

Know this

Question 2

PR segment?

Answer 2

• Segment preeceeding activation of QRS
• How long it takes for SA node to send signal and AV the ventricle mm fibers to recieve it
• 0.12-0.20 seconds

Question 3

What is the first negative deflection and second?

Answer 3

• Q
• S

Question 4

ST segment

Answer 4

• at isoelectric point, may be half mm above
  
  • not normal to be depressed more than half a mm
    
    • ST depression: Subendocardial injury
    • ST elevation: subepicardial or transmural injury
• period between QRS and T wave, how long ventricles are depolarizing

Question 5

QT interval

Answer 5

• should be less than half of previous R-R interval
• Length of time during ventricular systole

Question 6

How should the P wave look on 1,2, (limb leads) and V4,V6 (chest leads), AVF, AVR?

Answer 6

• Upright in 1,2,V4,V6, AVF
• Inverted in AVR

Question 7

ORS complex, describe Q wave

Answer 7

• Q wave not greater than 0.03 in width
• Q waves are small and narrow in AVL, AVF, V5 and V6

Question 8

Describe T wave direction in different leads?

Answer 8

• Upright in 1,2,V3-V6
• Inverted in AVR
• Variable in 3, AVL, AVF, V1-2
• height not greater than 5 mm in standard leads or 10mm in precordial leads

Question 9

What is the T wave assoc with when it is inverted or very tall and peaked?

Answer 9

• Inverted: ischemic pattern
• Tall: hyperkalemia

Question 10

Where do lead 1, AVL, V5 V6 pick up information and 2,3,AVF and

V1-4?

Answer 10

• 1, AVL, V5 V6 are lateral wall heart
• 2,3,AVF components in inferior diaphragmatic portion
• V1-4 pick up activity over anterior portioin

Question 11

What can shorten a PR interval?

Answer 11

• AV jxnl and low atrial rhythms
• Wolff parkinson white syndrome
• Lown ganong levine syndrome
• Glycogen storage disease
• Htn
• normal variationi

Question 12

Answer 12

• D is right bundle branch block
• Inverted Q previous MI
• Picture shows variation, you can have R waves with no Q, inverted waves, and missing waves

Question 13

If there is no Q wave can you have an R wave?

Answer 13

Yes, first up right deflection is R whether there is a Q wave or not

Question 14

ST segments

Answer 14

This is all artifact

Question 15

What are the best leads for reading P waves?

Answer 15

Lead II and V1

Question 16

On the ECG each dark line represents __ and each smaller box represents ___.

Answer 16

• 0.20 sec
• 0.04 sec

Question 17

What is the rate?

Answer 17

• ~125 BPM
• each big line is 300 150 100 75 60 50 43
• HR per min =300 divided by # large squares

Question 18

Rate

Answer 18

• physiologic sinus arrythmia, this is normal as you inhale rate increases and exhales as you decrease
• second R wave ~75 BPM

Question 19

What could be going on if P wave comes after QRS? What is rate?

Answer 19

• SVT
• Junctional rhythm seen in the picture
• rate is ~65-70 BPM

Question 20

What is 1 2 and 3 perpendicular to?

Answer 20

• 1 perpendicular to AVF
• 2 perpendicular to AVL
• 3 perpendicular to AVR

Question 21

What is axis?

Answer 21

• look at AVF, is it running positive or negative
• Look at Lead I, is it positive or negative
• axis is btw 0 and 90 as both are positive

Question 22

Normal axis should have positive deflection of leads ___ &___.

Answer 22

• lead I and aVF

Question 23

Describe what a left axis looks like.

Answer 23

• If lead one is positive and aVF is negative

Question 24

Describe right axis

Answer 24

• negative lead I
• Positive aVF

Question 25

Lead I is positive and aVF is negative, what is the axis?

Answer 25

left axis (-30 to -90)

Question 26

rate? axis?

Answer 26

Rate: ~40 BPM

Question 27

rate and axis?

Answer 27

* ~75 bpm * 1 and F are both positive so normal quadrant * aVR perpendicular to lead III * +30 degrees

Question 28

Answer 28

*