EKG Exam 1

Question 1

What is the rate of different foci according to their origination in the heart?

Answer 1

SA - 60-100
Atrium - 60-80
AV Junction - 40-60
Ventricle - 20-40

Question 2

What is it called when there is still electrical activity flowing through the heart but no mechanical activity?

Answer 2

PEA: pulseless electrical activity

Question 3

Deficiencies in what ions can affect how hard the heart pumps?

Answer 3

Potassium, sodium, and calcium

Question 4

What is the route of the electrical pathway

Answer 4

SA node to AV node to bundle of his to bundle branches (left and right) to purkinje

Question 5

Where is SA node located

Answer 5

Right atrium near opening of SVC

Question 6

Where is AV node located

Answer 6

Base of interatrial septum and extends into ventricular septum

Question 7

Where is the bundle of his located

Answer 7

Distal to AV node and before the bundle branches

Question 8

Where are the right and left bundle branches located

Answer 8

Intraventricular septum; carry impulses down the septum to both ventricles

Question 9

Where do the purkinje fibers carry the impulse?

Answer 9

Up the ventricular walls, inside out; endocardium to myocardium to epicardium

Question 10

Where is the issue if the QRS is wide?

Answer 10

Below the AV node; in the ventricle

Question 11

What can a 12 lead EKG identify that a rhythm strip can’t?

Answer 11

Electrical axis
Bundle branch blocks
Chamber enlargement/hypertrophy
Myocardial ischemia/infarction
Long/short QT syndrome
Pulmonary embolism
Pericarditis/cardiac tamponade

Question 12

In a normal EKG, I is _____ and III is _____

Answer 12

Positive; negative

Question 13

What leads are the P wave best seen in?

Answer 13

II and V1

Question 14

How long is the normal PR interval?

Answer 14

0.12-.20 seconds (3-5 blocks)

Question 15

What does the PR interval signify?

Answer 15

Beginning of atrial fibrillation to the beginning of ventricular depolarization

Question 16

What does a prolonged PR interval represent?

Answer 16

First degree AV block

Question 17

What are the 2 criteria for a pathological Q wave

Answer 17

Wider than 1 small block or >1/3 as deep as R wave is high

Question 18

How wide should a QRS wave be?

Answer 18

No more than 3 boxes (0.12 seconds)

Question 19

What does a wide QRS mean?

Answer 19

Electrical activity is not conducting through the system and is instead traveling from myocyte to myocyte

Question 20

What do ST elevations demonstrate

Answer 20

Myocarditis, pericarditis, LBBB, electrolyte abnormalities

Question 21

What do ST segment depressions signify?

Answer 21

Myocardial ischemia, hypokalemia, digitalis effect

Question 22

What are the septal leads

Answer 22

V1 and V2

Question 23

What are the anterior leads

Answer 23

V3 and V4

Question 24

What are the lateral leads

Answer 24

V5 and V6

Question 25

RA is

Answer 25

Both -

Question 26

LA is

Answer 26

+ and -

Question 27

LL is

Answer 27

Both +

Question 28

I connects

Answer 28

RA to LA (- to +)

Question 29

II connects

Answer 29

LA to LL (- to +)

Question 30

III connects

Answer 30

RA to LL (- to +)

Question 31

Normal QRS axis is

Answer 31

-30 to +90 (or just 0-+90?)

Question 32

Lead 1 positive + aVF positive

Answer 32

Normal axis

Question 33

Lead 1 positive + lead aVF negative

Answer 33

Possible left axis deviation (0 to -90)

Question 34

Lead 1 negative + Lead aVF positive

Answer 34

Right axis deviation (+90 to 180)

Question 35

Lead 1 negative + aVF negative

Answer 35

Extreme Axis deviation (-90 to 180)

Question 36

Right axis deviation (90-180) causes

Answer 36

LPFB RVH RBBB WPW Ventricular rhythm Dextrocardia Normal variant

Question 37

Pathological left Axis Deviation (-30 to -90)

Answer 37

LAFB LBBB WPW LVH Hyperkalemia Q-waves, MI Pregnancy

Question 38

Which leads look at the chest from the horizontal axis?

Answer 38

Precordial leads V1-V6

Question 39

Which leads look at the heart from the frontal axis?

Answer 39

Limb leads aVR, aVL, aVF, I, II, III

Question 40

Potential etiologies of AV heart blocks

Answer 40

Insult to AV node MI Digitalis toxicity Hypoxemia

Question 41

Treatment for first degree AV block

Answer 41

Usually none but depends on the severity

Question 42

Treatment for Wenckebach

Answer 42

None unless symptomatic; if symptomatic consider pacemaker

Question 43

Symptoms of Mobitz II

Answer 43

Light-headedness, dizziness, syncope, chest pain, regularly irregular heartbeat, may have bradycardia, hypo perfusion may cause hypotension

Question 44

How is Mobitz II treated

Answer 44

Pacemaker

Question 45

What are temporary pacemakers more

Answer 45

Sustain a patient’s heart rate in emergency situations

Question 46

What is a transvenous pacemaker

Answer 46

An electrode is threaded through a vein and into the right atrium, right ventricle, or both

Question 47

What is a transcutaneous pacemaker

Answer 47

Electrical current through patients chest with 2 large pads anterior/posterior; stimulates ventricular contraction

Question 48

Are are the two parts of a permanent pacemaker

Answer 48

Generator: controls rate/strength of electrical impulse Lead wires: relay electrical impulse to myocardium

Question 49

How does a demand pacemaker work

Answer 49

Pacemaker fires when rate falls below 75/min; is suppressed by NSR

Question 50

Indications for pacing

Answer 50

1. Bradycardia 2. Complete heart block 3. Second degree Type II heart block 4. Sick sinus syndrome

Question 51

What ekg findings indicate ventricular pacing

Answer 51

A spike followed by QRS complex Wide QRS LBBB pattern (bc pacing typically occurs in right ventricle) May or may not have P wave

Question 52

What is Marriott’s “approximation approach” to ventricular rate

Answer 52

300-150-100 75-60-50

Question 53

What are some causes of LBBB

Answer 53

Aortic stenosis Dilated cardiomyopathy Acute MI Primary dz of conduction system Lyme disease Side effects of trauma/surgeries