Normal CV Patient Physiology Flashcards
explain the cardiac cycle
- diastole - filling phase
– the heart relaxes and blood flows INTO the atria and ventricles - systole - pumping phase
– the heart contracts and pushes blood OUT
what happens in normal heart sounds:
– S1 “LUB”
– S2 “DUB”
– closure of AV valves, early ventricular systole, Peak R wave
– closure of SL valves, termination of ventricular systole & starts ventricular diastole, end of T wave
what is the correct equation for cardiac output?
a. E = mc2
b. HR + SV
c. [SBP + (DBPx2)]/3
d. EF + HR
B. HR + SV = CO
what is cardiac index?
– why is it the most accurate measure of cardiac function?
measurement of how well the heart is functioning
– more individualized than CO and ejection fraction bc it takes the patient’s body size in account
what is normal cardiac index?
2.5-4.0 L/min/m2
at what cardiac index is a patient likely in cardiogenic shock?
if CI falls below 2.2 L/min/m2
what is venous return?
– what are key features?
blood flow back to the heart from the body –> during inhalation, increased abdominal pressure pulls blood back towards the heart
– venous pressure is lower than arterial
distal venous pressure is greater than proximal venous pressure
what is the oxyhemoglobin dissociation curve?
relationship between the amount of O2 bound to hemoglobin (RBCs)
– it shows the ability of RBCs to release oxygen to tissues that need it
what is the minimum O2 concentration to prevent ischemia in tissue?
SpO2 of 90% = PaO2 of 60mmHg
** think clinically - stop walking patient if SpO2 is < 90%… this is why (muscles don’t have enough O2 providing them)
what does a left shift of the oxyhemoglobin dissociation curve mean?
the tissues don’t need more oxygen so hemoglobin holds onto the O2
–> ex: sleeping
what does a right shift of the oxyhemoglobin dissociation curve mean?
some tissues need an increase in oxygen so hemoglobin releases O2
–> ex: exercising
properties of L AND R shifts of the oxyhemoglobin curve:
– ____ O2 bound to Hgb
– _____ partial pressure of O2
– _____ temp & muscle work
– ____ blood pH
LEFT:
– more
– lower
– lower
– higher (less acidic)
RIGHT:
– less
– naturally happens with exercise
– higher
– lower (more acidic)
Normal HR:
60-100 bpm
Name the scale rating for the pulse amplitude:
– normal pulse
– absent pulse
– bounding pulse
– 2+
– 0 –> no circulation
– 4+ –> increased stroke volume and ejection fraction
when heart rate and stroke volume increase in a normal individual who is exercising, what happens to their cardiac output?
increases –> primary limitation to max O2 consumption during increasing activity
an individual’s angina threshold is strongly correlated to ____ and ____
– based on the O2 demand, patient’s WITHOUT pathology will experience angina _____ than someone with pathology
HR and SBP
– later (higher threshold)
HR response to exercise in a normal individual:
– _____ linearly as workload & O2 demands increase
– _______ linearly as workload & O2 demands decrease
– remains _____ during steady state
– increases
– decreases
– the same
You are working with a 80 year old patient. You first start by performing upper body exercises.
– will this patient have a higher or lower MAX HR than someone who is 15 years old?
– will you expect her to have a higher or lower HR response to the exercise being performed? Why?
– what is a QUICK way to calculate her max HR?
– what is a slower, yet more precise way to calculate her max HR?
– lower - max HR drops with age
– higher - upper body exertion causes higher HR response
– 220-age
– 207 - (0.7xage)
normal BP:
normal MAP:
– why would you choose to check MAP over BP?
– how do you calculate MAP?
LESS THAN 120/80
70-110 mmHg
– better indicator of end organ perfusion
– MAP = [SBP + (DBPx2)]/3
you should not perform mobility with your patient if they have a MAP < _____
< 65 – not enough O2 for organs
what is systolic BP?
what is diastolic BP?
– pressure during ventricular contraction ; force to send blood into distal arteries while aortic valve is open
– pressure during ventricular relaxation while filling ; force to send blood into coronary arteries while valve is closed
how is SBP affected during exercise? DBP?
– Pulmonary vascular resistance (PVR)?
– increases linearly w/ increased workload
– only fluctuates ~10mmHg
– drops with activity
normal BP responses to exercise:
– rise in ____ is greater than the drop in ____
– upper body exercises cause _____ SBP response
– women have ____ pronounced BP response than men
– _____ body exercise results in greater blood volume redistribution
– redistribution goes away from ___ and ___ towards __
– CO ; PVR
– higher
– less
– lower
– organs & non working muscles ; working muscles
what is a normal SPO2 response to exercise?
remains relatively stable
