Test I (SECTION I) Definitions, Concepts, Hemodynamics Flashcards
Pulmonary veins carry ______
oxygenated blood
circumflex artery goes to
Left main CA, right main CA, Left anterior descending CA (which leads to marginal branch)
Diastole is
end of ventricular filling
EDV is proportional to
Venous return
SV =
EDV - ESV
Ejection Fraction (EF) =
SV/EDV
EF is best indicator for
heart performance and heart disease prognosis
Left ventricular norm for EF at rest is
62%
Left ventricular norms for max exercise is
80%
Left ventricular volumes _____ with increase in exercise intensity
Increase, but level off quickly
Cardiac output (Q) =
HR x SV
For cardiac output blood leaves ________
the left ventricle
Cardiac Index =
Q/ body surface area
Preload is:
(EDV) volume of the left ventricle at the end of diastole
Preload depends on
venous return & compliance of ventricle
Afterload is
resistance to ventricular emptying during systole or the amount of pressure the left ventricle must generate to squeeze blood into the aorta
After load is synonymous in a healthy heart with
aortic pressure & mean arterial pressure (MAP)
Frank Starling law of the heart is
the heart will contract with greater force as preload is increased
Myocardial Contractility
the squeezing contractile force that the heart can develop at a given preload (determines SV)
Myocardial contractility is regulated by:
Sympathetic nerve activity (MOST)
Catecholamines (Epinephrine/norepinephrine)
amount of contractile mass
Drugs
Starlings law Graph: x & y axis and how curves are
SV (Y Axis)
Preload (X Axis)
More SV = more contractility
Increased Contractility is related to:
exercise
catecholamines (epinephrine & norepinephrine)
excitement or fear (fight or flight)
Drugs (Digitalis & sympathomimetics)
Decreased Contractility is related to:
loss of contractile mass (likely due to Heart Attack)
Myocardial muscle disease (Cardiomyopathy)
Drugs )anesthetics, barbiturates)
What is Cardiomyopathy?
Malfunctioning and/or malformed heart
How does exercise effect myocardial contractility?
Increases it by increasing beta sympathetic adrenergic nerve output
AVO2D means
Arteriovenous Oxygen Difference
AVO2D definition
difference in oxygen content between arterial and venous blood (ml O2/100ml blood)
VO2 means
Oxygen Consumption
VO2 Definition
the rate at which oxygen can be used in energy production and metabolism
Types of VO2
Absolute: O2/min
relative: O2/kg body weight / min.
what is the Fick equatoin
VO2 = Q x AVO2D
VO2max definition
maximum rate at which a person can take in and utilize oxygen to create usable energy (estimated with VO2 peak)
Myocardial Oxygen Consumption
VO2 of the heart
estimated by rate pressure product (RPP)
RPP =
HR x SBP
Systolic Blood Pressure
pressure measured in brachial artery during systole
Diastolic Blood Pressure
pressure measured in brachial artery during diastole
Systole
ventricular emptying and ventricular contraction period
Diastole
ventricular filling and ventricular relaxation
Mean Arterial Pressure (MAP)
“average” pressure throughout the cardiac cycle against the walls of the proximal systemic arteries
MAP =
.33(SBP - DBP) + DBP
Total Peripheral Resistance (TPR)
the sum of all forces that oppose blood flow
TPR =
(8)(V)(L) / (pi)( r^4)
V: blood viscosity
L: length of vasculature
r: vessel radius
Ohm’s Law
flow of the blood
Flow = (upstream P - downstream P) / resistance
Flow (Q) =
MAP / TPR = (P aorta - P vena cava) / TPR
(P aorta - P vena cava) is almost 0 in a health person
Resting Q is normall about __ liters/minute
5-6
Minute Ventilation (Ve)
amount of air passing through the lungs in one minute
Dyspnea
breathing difficulty
Respiratory Exchange Ratio
amount of CO2 expired by the lungs divided by the amount of O2 extracted from the air in the lungs
VCO2/VO2
RER =.7,
RER =.85
RER = 1.0
100% fat 0% carb
50$% fat 50% carb
0% fat 100% carb
Gas Exchanges happens in
capillary beds and lungs
systemic arteries have a ____ compliance, veins have a ____ compliance
low, high
After heart attack left ventricular pressure lessons which causes
pressure behind it to increase, causing fluid to seep out of the lungs
afferent
going toward spinal column
efferent
going away from spinal column
Agonist
body molecule or drug “stimulator”
Agonist in adrenergic system
epinephrine & norepinephrine
Antagonist
body molecule or drug “in-activator”
Antagonist examples
drugs known as blockers
alpha 1 stimulation
constriction of blood vessels
vascular smooth muscle activation
Alpha 2 stimulation
increased central sympathetic outflow
beta 1 stimulation
increase in HR
increase in myocardial contractility
increase in renin secretion
increase in fluid retention
beta 2 stimulation
dilation of lung bronchioles
anastomosis is also known as a
shunt. Connects two previously separated vessels
