Ch.15 EKG/ECG

Question 1

What is cardiac output?

Answer 1

amount of blood ejected from the ventricles each minute

Question 2

How is cardiac output calculated?

Answer 2

the product of stroke volume times heart rate

Question 3

How is cardiac output measured?

Answer 3

electrocardiograph/gram (EKG or ECG)

Question 4

What is a cardiac cycle?

Answer 4

the beginning of one ventricular contraction (systole) until the beginning of another

Question 5

What are working cells of the heart?

Answer 5

cardiac muscle/myocardium of the atria and ventricles

Question 6

What are the specialized cells of the heart?

Answer 6

• sinoatrial (SA) node
• atrioventricular (AV) node
• budle of HIS
• purkinjie fibers

Question 7

What do the specialized cells of the heart do?

Answer 7

originate and transmit electrical impulses across the myocardium and regulate the rhythm of the cardiac cycle

Question 8

What doe an SA node do? (sinoatrial)

Answer 8

initiates the electrical sequence of a cardiac cycle

Question 9

What is an isoelectric line?

Answer 9

the baseline of an ECG which signifies the resting membrane potentials

Question 10

Describe a P wave

Answer 10

• depolarization of atrial muscle cells
• SA node fires at start of the wave
• atrial contraction begins and the peak of the wave

Question 11

Describe a QRS complex

Answer 11

represents the depolarization of the ventricular muscle cells

Question 12

What is the ‘Q’ in a QRS complex?

Answer 12

-the downward deflection

Question 13

What is the “R” in a QRS complex?

Answer 13

initial upward deflection where contraction commences

Question 14

What is the “S” in a QRS complex?

Answer 14

the return to the baseline

Question 15

Describe a T wave

Answer 15

when the ventricular muscles repolarize

Question 16

Describe a U wave

Answer 16

represents the repolarization of the papillary muscle and purkinjie fibers

Question 17

What is a PR interval?

Answer 17

-the beginning of the Pwave to the peak of R in a QRS complex

Question 18

What does a prolonged PR interval show?

Answer 18

an AV block

Question 19

What is the 1st step in an ECG analysis?

Answer 19

Check if the rhythms are regular or irregular

-regular=distance between QRS complexes

Question 20

What is the 2nd step in an ECG analysis?

Answer 20

Are the QRS complexes similar? Narrrow?

-QRS should not exceed 3sm squares

Question 21

What does a widened QRS complex demonstrate?

Answer 21

hypertrophy-ventricular enlargment

Question 22

What doe a narrow QRS complex demonstrate?

Answer 22

rhythm being initiated by a pacemaker at the AV node

Question 23

What is the 3rd step in an ECG analysis?

Answer 23

are all the Pwaves similar with normal PR intervals?

-normal=3-5sm squares

Question 24

What is the 4th step in an ECG analysis?

Answer 24

is the rate normal?

-count the boxes between QRS complexes and divide by 300

Question 25

What does bradycardia look like on a ECG?

Answer 25

wide spaces between QRS complexes rate below 60

Question 26

What does tachycardia look like on an ECG?

Answer 26

spaces between QRS complexes are narrow and above 100

Question 27

What does atrial fibrillation look like on an ECG?

Answer 27

irregular spaces between the QRS complexes

Question 28

What does asystole look like on an ECG?

Answer 28

a near flat line

Question 29

What is the 5th step in an ECG analysis?

Answer 29

do the waves and sequences proceed in normal sequence?

-each Pwave should be followed by a QRS complex, followed by a Twave

Question 30

What is the most common cardiac arrhythmia?

Answer 30

atrial fibrillation

Question 31

What is atrial fibrillation?

Answer 31

quivering contraction of the cardiac muscle fibers