CV Formulas and relationships

Question 1

Ohms Law

Answer 1

Q= Change in Pressure / Resistance

Question 2

Cardiac Output

Answer 2

CO = SV x HR CO = MAP/ SVR

Question 3

MAP

Answer 3

MAP = (CO x SVR) + CVP MAP = Systolic + 2(Diastolic) / 3

Question 4

FICKS PRINCIPAL

Answer 4

CO = TOTAL BODY OXYGEN CONSUMPTION / (PULMONARY ARTERY O2-PUMONARY VEIN O2) CO = VO2 / (Ca02 - Cv02)

Question 5

VENOUS RETURN

Answer 5

VR = PSF(7)- PRA(0) / RVR(1.4) VR = MEAN SYSTEMIC FILLING PRESSURE

Question 6

REYNOLDS #

Answer 6

NR = (DENSITY)(DIAMETER)(MEAN VELOCITY) / VISCOSITY

Question 7

RESISTANCE/PRESSURE AND FLOW

Answer 7

Q = (PIE)(r to the 4th) / 8Ln ) (P1-P2)

Question 8

Resistance in Parallel

Answer 8

1/Rtotal = 1/R1 + 1/R2 + …

Question 9

Capillary Blood Flow

Answer 9

T= Pr r = radius

Question 10

Factors that Affect Pressures (5)

Answer 10

Aortic Distensibility Stroke Volume HR Peripheral Resistance Ejection Velocity

Question 11

Systemic Vascular Resistance

Answer 11

SVR = (MAP - RAP / CO) x 80 SVR = (MAP - CVP / CO) x 80

Question 12

Afterload

Answer 12

Tension is proportional to Pressure times radius / wall thickness

Question 13

Stroke Work

Answer 13

SW = SV x MAP

Question 14

Factors that effect inotropy

Answer 14

HR Sympathetic activation Parasympathetic inhibition Circulating Catchecholamine Afterload

Question 15

Factors that increase ventricular filling (preload) 5

Answer 15

1. Increased atrial contractility 2. Increased ventricular compliance 3. Increased CVP 4. Increased Aortic Pressure - increased after load - decreased stroke volume = increased end systolic volume - Secondary increase in preload 5. DECREAED Heart Rate

Question 16

Two things that increase CVP

Answer 16

1. Increased thoracic venous volume - total blood volume - Venous return, r/t muscle contraction, respiration and gravity 2. Decreased venous compliance

Question 17

Stroke volume and increased preload

Answer 17

Increased preload = increased SV r/t increased end diastolic volume

Question 18

Stroke volume and increased afterload

Answer 18

Increased afterload = Decreased stroke volume r/t increased end systolic volume

Question 19

Stroke volume and increased isotropy

Answer 19

Increased isotropy = Increased stroke volume r/t decreased end systolic volume

Question 20

Ejection Fraction

Answer 20

EF = SV / EDV SV = EDV- ESV

Question 21

Decreased O2 delivery to tissue

Answer 21

Supply / demand mismatch causes: Adenosine Release Increased Co2 - Especially in Brain ATP & ADP Release Histamine Release Increased K+ an Mg++ ions Increased H+ ions, acidosis Ultimately Causing VASODILATION

Question 22

Cardiac index and Stroke Index

Answer 22

CI = CO / BSA BSA = M2 SI = SV / BSA

Question 23

02 Delivery

Answer 23

O2 Delivery = CBF x CaO2 CBF = Coronary blood flow (mL / Min) Ca02 = Oxygen concentration of arterial blood (mL 02 / mL Blood)

Question 24

Cardiac Work

Answer 24

Cardiac Work = SW x HR How much work being done for a unit of time Cardiac minute work or Ventricular minute work