Circulation & Output measurements

Question 1

Period of cardiac cycle during coronary B. flow in the L ventricle is lowest

Answer 1

At end of isovolumetric contraction -> L ventricle contraction
During systolic periods

Question 2

Flow is proportional to

Answer 2

pressure difference

Question 3

Flow is inversely proportional to

Answer 3

the resistance

Question 4

Isovolumetric contraction systolic

Answer 4

Flow lowest -> perfusion lowest
LV contraction -> coronary artery P increases
(valves not open)

Question 5

Ventricular relaxation diastolic

Answer 5

Coronary vessel not compressed

Flow highest -> perfusion BEST

Question 6

Effect of cardiac dilation on tension and myocardial perfusion

Answer 6

Increases tension

Highest tension is at lowest P thus lowest flow so low perfusion

Question 7

Location of most common myocardial infarction

Answer 7

Left ventricle

Question 8

Transmural

Answer 8

Through whole ventricular wall
Flow decreased through systole
Inner mc vessels most compressed during systole

Question 9

Aortic regurgitation

Answer 9

Backward flow diastolic murmur
Diastolic P rapidly decreases
Significant drop in aortic P
Decreases perfusion
Compensation - more forceful contraction
Systolic P increases

Question 10

Increases HR Diastolic

Answer 10

Shortens its period
Less perfusion
NE decreases diastolic time so decreases perfusion

Question 11

Increases in HR systolic

Answer 11

Increases its period

Less perfusion

Question 12

Dye dilution method

Answer 12

Inject dye measure at diff points.

CO = mg injected / (point mg/L X min/60) = 5 L min

Question 13

Thermal dilution

Answer 13

d

Question 14

Simple method echo

Answer 14

numerous short axis measurements. Radioactive indicator

Question 15

Doppler method

Answer 15

Measures velocity of low in the outflow tract of the left ventricle throughout ejection periods
SV = FVI X valve area