Heart Function and Cardiac Cycle

Question 1

What is Einthoven’s Triangle?

Answer 1

lead placements on the right and left arms and the left leg for EKG

Question 2

what is the most common lead to view on an EKG?

Answer 2

lead 2

Question 3

voltage changes in the direction of the _______ lead is registered as an upward deflection

Answer 3

positive

Question 4

this type of EKG is arranged to analyze information in a circular fashion (cross section) and provides better resolution

Answer 4

12 lead EKG

Question 5

slow HR

Answer 5

bradycardia <60bpm

Question 6

fast HR

Answer 6

tachycardia >100bpm

Question 7

this occurs when there is no coordinated synchronized rhythm of the heart

Answer 7

fibrilation

Question 8

this is a stray signal that tells the chamber to contract early

Answer 8

premature beats (PAC and PVC)

Question 9

S-T elevation indicates this condition

Answer 9

myocardial infarction

Question 10

S-T depression may indicate _______

Answer 10

ischemia

Question 11

this occurs when the electrical signals from the atria to the ventricles is disrupted

Answer 11

heart block

Question 12

what is indicative of a 1st degree heart block?

Answer 12

widened PR interval (>0.2)

Question 13

what is indicative of a type 1 second degree heart block?

Answer 13

PR interval becomes wider and wider until it drops QRS

Question 14

what is indicative of a type 2 second degree heart block?

Answer 14

intermittent dropping of the QRS without progressive widening of PR interval

Question 15

what is indicative of a 3rd degree heart block?

Answer 15

independent P and QRS (completely uncoordinated)

Question 16

this is filling/ the relaxation phase

Answer 16

diastole

Question 17

this is emptying/ the contraction phase

Answer 17

systole

Question 18

this refers to how much blood is in the chamber after filling

Answer 18

end diastolic volume/ preload (120mL)

Question 19

this refers to how much blood is left after a contraction

Answer 19

end systolic volume (50mL)

Question 20

this refers to the volume of blood ejected in one contraction

Answer 20

stroke volume (SV)

Question 21

SV equation

Answer 21

EDV-ESV (about 70mL)

Question 22

this refers to the amount of blood pumped out of each ventricle in one minute

Answer 22

cardiac output (CO)

Question 23

CO equation

Answer 23

HR x SV

Question 24

what is normal CO usually around?

Answer 24

about 5.25 L/min

Question 25

true or false- in a healthy system, SV is NOT constant

Answer 25

false- normally SV is fairly constant

Question 26

What does the Frank-Starling Law state?

Answer 26

higher preload= more stretch= more powerful contraction

Question 27

this refers to pressure caused by resistance of the aorta or pulmonary artery to blood flowing into it

Answer 27

afterload

Question 28

do negative inotropic effects increase or decrease SV/ CO?

Answer 28

decreases SV/ CO

Question 29

do positive inotropic effects increase or decrease SV/ CO?

Answer 29

increases SV/ CO

Question 30

what occurs during atrial systole: active ventricular filling in the cardiac cycle?

Answer 30

SL valves are closed while AV valves are open depolarization of SA nodes lead to atrial contraction completes ventricular filling

Question 31

what events occur during the period of isovolumetric contraction phase of the cardiac cycle?

Answer 31

SL and AV valves closed contraction, but no volume changes begins after QRS complex increased pressure in ventricles causes AV valves to close beginning of ventricular systole

Question 32

what events occur during the rapid ventricular ejection/ reduced ventricular ejection phases of the cardiac cycle?

Answer 32

SL valves open, AV valves are closed pressure in ventricle> pressure in aorta/ pulmonary trunk blood ejected from ventricles after initial spurt, pressure drops

Question 33

what occurs during the period of isovolumetric ventricular relaxation in the cardiac cycle?

Answer 33

SL and AV valves closed completion of T wave--> ventricular repolarization and relaxation rapid fall of ventricular pressure

Question 34

what occurs during the rapid, passive ventricular filling phase of the cardiac cycle?

Answer 34

AV valves open, SL valves are closed atrial pressure> ventricular pressure so AV valves open blood flows into relaxed ventricles

Question 35

pressure in the _____ maintains an elevated diastolic pressure

Answer 35

aorta

Question 36

diastolic pressure in the ________ drops to almost zero

Answer 36

ventricle

Question 37

explain the 4 parts of the left ventricular volume loop

Answer 37

filling- volume increases isovolumetric contraction- mitral and aortic valves closed aortic valve opens- volume decreases isovolumetric relaxation- valves are closed

Question 38

does increased preload and increased contractility increase or decrease SV?

Answer 38

increase

Question 39

does increased afterload increase or decrease SV?

Answer 39

decrease

Question 40

abnormal heart sound

Answer 40

murmur

Question 41

sound heard with incompetent valve (doesn't close correctly)

Answer 41

swishing sound

Question 42

sound heard with stenotic valve (narrowed)

Answer 42

high pitch/ clicking sound