Dysrhythmia Interpretation And Management PART 1

Question 1

Flow of electrical system of the heart

Answer 1

1st: SA node (pacemaker): 60-100bpm

2nd: AV node: 40-60
-if SA doesnt work

3rd: ventricular 20-40
-if AV doesnt work

Question 2

Sympathetic nervous system
(Neurotransmitters)
(What they do)

Parasympathetic nervous system
(Neurotransmitters)
(What they do)

Answer 2

SNS: (fight/flight)
-epinephrine and norepinephrine
-increase HR/contractility, vasoconstriction

PSNS: (rest/digest)
-acetylcholine
-decrease HR/contractility, vasodilation

Question 3

Depolarization vs repolarization (what are theses)

Contraction and relaxation are what

Answer 3

Depolarization and repolarization are electrical stimuli

Depolarization: contraction and heart muscles

Repolarization: relaxation of heart

Contraction and relaxation: mechanical response to stimuli

Question 4

1.There is no heart beat without first having had what?

2.Electrical stimulus does not guarantee what?

Answer 4

1.Depolarization

2.Mechanical response
(There could be mechanical problem making incabable of pumping-PEA)

Question 5

How often to change electrodes

Answer 5

24hrs

Question 6

What is the placement of electrodes?

3lead

5lead

Answer 6

3lead
-RA (white) =upper
-LA (black) =upper
-LL (red) =lower

5lead:
-RA (white) (snow)
-RL (green) (grass)
-LA (black) (smoke)
-LL (red) (fire)
-V (center)

Question 7

If you have bad rhythm what to check 1st

Answer 7

Artifact (leads)

Question 8

12 lead EKG shows us what

Answer 8

Picture of electrical conduction of the heart (depolarization and repolarization)

Question 9

Horizontal plane vs vertical plane of EKG

Answer 9

Horizontal: time (seconds)

Vertical: voltage (mm)

Question 10

Time and voltage readings

Big box
Little box

Answer 10

Big box: (15 is 3 seconds/30 is 6 seconds)
-5mm
-0.2sec

Little box:
-1mm
-0.04sec

Question 11

Isoelectric line

Answer 11

Flat line on the EKG paper that represents:

-the resting membrane potential of cardiac cells
(The line we always want to return to)

Question 12

How to determine pulse with a EKG

What two ways 3 ways for a regular rhythm

Answer 12

Count # of small squares between 2 R waves
-divide by 1500

Count # of big squares between 2 R waves
-divide by 300

Count # of R waves in 6 second strip
-multiply by 10

Question 13

How to determine pulse with a EKG

Irregular rhythms

Answer 13

Count # of R waves in a 6 second strip strip
-multiply by 10

(Can also be used for regular rhythm)

Question 14

P wave

What is happening
How long do we want it

Answer 14

Atrial depolarization

Longer than 0.20 seconds-conduction delayed

Question 15

P wave

4 types and what they mean

Answer 15

Peaked P wave:
-right atrial hypertrophy

Inverted P waves:
-SA node not the pacemaker

Varying P wave:
-impulse origin varies

Missing P wave:
-junctional or AV block rhythm

Question 16

PRI (PR interval)

What is it
What is measured
Duration

Answer 16

Beginning of atrial depolarization (contraction)
To beginning of ventricular depolarization

Measures (start of P waves to QRS)

Duration: 0.12-0.20

Question 17

PRI (PR interval)

Variations

Answer 17

Short PRI:
-SA node not the pacemaker

Prolonged PRI:
-impulse delay thru AV node (heart block)

Question 18

QRS complex

What is it
Duration
What needs to be present
What does S do

Answer 18

Ventricular depolarization (contraction)

Duration: 0.06-0.10 (as long as its less than 0.12)

R must be present
(Q may be absent)

S goes below isoelectric line

Question 19

QRS complex

Prolonged QRS >0.12

Causes

Answer 19

BBB
VT
PVC (premature ventricular contraction)

Question 20

ST segment

Represents what
Should be on what

Answer 20

End of ventricular depolarization (contraction)
Beginning of ventricular repolarization (relax)

(Extends from end of S waves to beginning of T wave)

Whole thing should be on isoelectric line

Question 21

ST segment variations

What to do if there is variation

Answer 21

ST elevation: 1mm or above line
myocardial injury

ST depression
myocardial ischemia

IF ST SEGMENT VARIATION IS NOTED AND IS NEW
-order a 12-lead and contact HCP

Question 22

STEMI vs NSTEMI

Do we need one lead or more

Answer 22

STEMI (ST elevated MI)
NSTEMI (non-ST elevated MI)

We need to evaluate more than one lead

Tx: contact provider for 12-lead ekg

Question 23

T wave

Represents
Amplitude needed

Answer 23

Ventricular reploarization

Amplitude (0.5-1 or less)
-first one to measure amplitude-

Question 24

T wave variations

Answer 24

Peaked T wave (EXAM)
-hyperkalemia

Notched t wave (pericarditis)

Inverted T wave (ischemia)
-give O2

Question 25

QT interval

Represents

Duration

Answer 25

Time needed for:
Ventricular depolarization-repolarization cycle

Duration: 0.36-0.44sec

Question 26

Electrolyte disturbances

Hyperkalemia

Answer 26

Tall peaked T waves (exam)

-prolonged PRI
-loss of P wave
-widening QRS
-V fib
-asystole

Question 27

Electrolyte disturbances

Hypokalemia

Answer 27

Flattened T wave
PVCs
Bradycardia

Question 28

Electrolyte disturbances

Hypocalemia vs hypercalemia

(Didnt cover really)

Answer 28

Hypo:
-prolonged QT
-ventricular tachycardia

Hyper:
-shortened QT
-shortened ST

Question 29

Electrolyte disturbances

Hypomagnesemia

Answer 29

Torsades de pointes (EXAM)