EKG Axis Deviation Flashcards Preview

PTRS 826 Exam 2 > EKG Axis Deviation > Flashcards

Flashcards in EKG Axis Deviation Deck (8)
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1
Q

Term: average [mean] direction of depolarization [or vector] as QRS complex travels through the ventricles

A

Axis

2
Q

We care about abnormal axes because they can be suggestive of _____1_____. They do not absolutely ___2___ _3_ ____4____.

A
  1. Disease
  2. Rule
  3. In
  4. Conditions
3
Q

List the limb leads to examine to determine axis deviation (6)

A

I**

II

III

aVR

aVF**

aVL

** Focus for determination

** Need to determine if the lead is mostly upward or downward deflected

4
Q

Describe values for

  1. Normal axis deviation
  2. Left axis deviation
  3. Right axis deviation
A
  1. -30 to +90
  2. More negative than - 30
  3. More positive than +90
5
Q

List causes of right axis deviation (8)

A
  1. Normal in children and tall thin adults
  2. R ventricular hypertrophy
  3. Chronic lung disease (w/ w/o pulmonary HTN)
  4. Anterolateral myocardial infarction
  5. L posterior hemiblock
  6. Pulmonary embolus
  7. Atrial septal defect
  8. Ventricular septal defect
6
Q

List the causes of left axis deviation (7)

A
  1. L anterior hemiblock
  2. Q waves of inferior MI
  3. Artificial cardiac pacing
  4. Emphysema
  5. Hyperkalaemia
  6. Athletes [increased mm mass]
  7. High BP [adapated to increased load > increased mm mass]
7
Q

Causes of extreme axis deviation (5)

A
  1. Emphysema
  2. Hyperkalemia
  3. Lead transposition
  4. Artifical cardiac pacing
  5. Ventricular tachycardia
8
Q

List the 2 general methods to determine axis deviation

A
  1. Mean QRS axis is midway b/t 2 leads that register tall R waves of equal amplitude
  2. Mean QRS axis is directed at right angles to any extremity lead that has a biphasic isoelectric complex