11. EKG part 3 Flashcards Preview

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Flashcards in 11. EKG part 3 Deck (11):
1

What does it mean to be balanced and bipolar on an ECG? Significance for QRS complex?

  • Equal amplitudes up (+) & down (-)
  • QRS complex is balanced and bipolar --> axis travels perpendicular to this lead

2

What are the steps you take every time you encounter an EKG?

  1. Determine if EKG is interpretable
  2. Determine the rate
  3. Check conduction system (pr & QRS intervals)
  4. Determine the axis
  5. Analyze the rhythm

3

What is the normal appearance of the aVR lead?

  • P and QRS are negative

4

Why is it normal for the aVR lead to be negative?

It's the only lead viewing the heart's receding depolarization from above

5

What is the most common cause of upright P and QRS waves lead aVR?

Switched limb leads

6

What 4 characteristics do we evaluate to confirm the cardiac rhythm?

  • Rate/timing
  • QRS width
  • P wave characteristics
  • Regularity of cardiac cycles

7

What does a narrow QRS width denote? Wide?

  • Narrow: supra-ventricular origin
  • Wide: ventricular origin

8

What are the criteria for a normal sinus rhythm?

  • HR = 60-100 bpm
  • QRS width is narrow (<0.10 ms)
  • P wave is positive in lead II
  • PR duration 0.12 - 0.20 ms
  • 1:1 P:QRS ratio
  • Regularly spaced QRS's

9

What is sinus arrhythmia?

Phasic variation of HR w/ inspiraiton (higher HR) and expiration (lower HR)

10

What characterizes a high atrial premature beat?

Upright P wave suggests an ectopic focus high in the atria

11

What characterizes a junctional premature beat?

  • Inverted (retrograde) or absent P wave
  • P waves too close to QRS (<0.12 secs)