EKG

Question 1

what is conductivity?

Answer 1

ability for cardiac cells to transmit action potential from one cell to another

Question 2

what is rhythmicity?

Answer 2

ability for cardiac cells to spontaneously generate an action potential at a regular rate

Question 3

what is a normal SA node rate?

Answer 3

60-100 BPM

Question 4

if the SA node is blocked or damaged, ____ will step up to be the pacemaker of the heart

Answer 4

AV node

Question 5

if the AV node is damaged, then ________ will take over to maintain cardiac output to keep the patient alive

Answer 5

the Purkinje fibers

Question 6

what is the normal rate for the purkinje fibers?

Answer 6

15-40 BPM

Question 7

what does a P wave show?

Answer 7

atrial depolarization atrial contraction & shows when the SA node is firing

Question 8

what does the PR interval show?

Answer 8

time in seconds from onset of atrial depolarization to onset of ventricular depolarization

Question 9

what does the QRS interval show?

Answer 9

ventricular depolarization & atrial repolarization; time it takes for the impulse to travel through the bundle branches & purkinje fibers

Question 10

what is the J point?

Answer 10

point at which the QRS returns to the isoelectric line; marks beginning of ST segment

Question 11

what does a normal ST segment look like?

Answer 11

flat & same level as the isoelectric baseline

Question 12

what may an elevated or depressed ST segment indicate?

Answer 12

an MI!

Question 13

what does a T wave show?

Answer 13

ventricular repolarization (ability of the heart to have another action potential)

Question 14

what can peaked T waves be caused by?

Answer 14

high potassium levels

Question 15

what can flat T waves be caused by?

Answer 15

low potassium levels

Question 16

what does a QT interval show?

Answer 16

time in seconds from beginning of ventricular depolarization to the end of ventricular repolarization

Question 17

what is another way to calculate heart rate in addition to counting each R complex?

Answer 17

counting the number of small boxes between the R to R complexes and dividing 1500 by that number

Question 18

what is a normal PR interval?

Answer 18

0.12-0.20 or 3-5 little boxes

Question 19

what is a normal QRS interval?

Answer 19

< 0.12 or less than 3 little boxes

Question 20

what is considered a normal QT interval?

Answer 20

“normal” determined according to heart rate; less than half of the R-R interval

Question 21

which med may cause a prolonged QT?

Answer 21

Amiodarone

Question 22

if a PR interval is prolonged, what does this mean & what is this considered?

Answer 22

it is taking too long for the electrical impulse to leave the AV node; it’s considered a First-Degree AV block

Question 23

if a QRS interval is prolonged, what does this mean & what is this considered?

Answer 23

it is taking too long for the electrical impulse to travel down the bundle branches; it’s called a bundle branch block (patients w this may have had previous MIs & there is damage to that bundle branch)

Question 24

what does depression or elevation of an ST segment determine?

Answer 24

determines whether there is an acute MI, STEMI or N-stemi

Question 25

what do absence of P waves determine?

Answer 25

atrial dysrhymias, afib & aflutter

Question 26

what do you do if a patient has an artifact EKG reading?

Answer 26

reposition their leads

Question 27

what can bradycardia be caused by or associated with?

Answer 27

sleep, severe pain, inferior wall myocardial ischemia & spinal cord injuries meds: Digitalis, beta-blockers & Ca channel blockers (cardizem)

Question 28

how do you treat a patient for bradycardia?

Answer 28

assess them first! if they are asymptomatic, no treatment is needed. if they are symptomatic, administer atropine 1.0 mg IV every 3-5 min (3 mg max)

Question 29

if Atropine is ineffective, what is done?

Answer 29

transcutaneous pacing (TCP); pacing pads are placed over the skin & pacer machine is applied to increase the patient's cardiac rate

Question 30

which med infusions may be used as an alternative to TCP?

Answer 30

Dopamine (5-20 mcg/kg/min) & epinephrine (2-10mcg/min)

Question 31

what are potential causes of sinus tachy R/T increased sympathetic tone?

Answer 31

stress, exercise, stimulants (caffeine & nicotine)

Question 32

what are potential causes of sinus tachy associated w clinical problems?

Answer 32

fever, anemia, hyperthyroidism, hypoxemia, heart failure & shock

Question 33

which drugs can be a cause of sinus tachy?

Answer 33

Atropine (blocks vagal tone allowing sympathetic tone to take over), epinephrine & dopamine

Question 34

what is the first line treatment for sinus tachy?

Answer 34

treat the cause! (fix underlying issues e.g, oxygen, sedation, fluids & blood)

Question 35

which meds are used to treat sinus tachy?

Answer 35

beta-blockers or Ca channel blockers ( both decrease HR)

Question 36

which meds can cause sinus dysrhymias / arrhymias?

Answer 36

digitalis or morphine

Question 37

how can you tell when a dysrhymia is present on an EKG strip?

Answer 37

if the RR intervals are irregular by more than 0.12 seconds; the rate gradually increases w inspiration & gradually decreases w expiration

Question 38

do sinus dysrhymias / arrhymias require treatment?

Answer 38

generally do not unless there are long pauses!