Exam 1 Lecture 5 (2-7-23) Coronary Perfusion/PDA/Ballon Pumps/Cardiac (Andy's cards) Flashcards
Which heart valve issue would most benefit from an intra-aortic balloon pump?
Mitral valve regurgitation.
An intra-aortic balloon pump will reduce the afterload
The degree of backflow for mitral valve regurgitation is dependent on what factors?
- How compromised are the valves
- Amount of time spent in systole
- Amount of afterload that the LV will encounter
What HR would be beneficial for someone with mitral valve regurgitation?
80 to 90 bpm.
Remember this is considered slightly tachycardic; normal HR is 72 bpm
When does the balloon pump inflate?
When does the balloon pump deflate?
Inflation of the balloon during diastole will act as a pump pushing blood along the aorta.
Deflation of the balloon during systole will produce an artificially low afterload that will reduce the workload of the LV.
What is the balloon pump filled with?
Why is it filled with this substance?
Helium
Cheap, Inert, and Non-toxic
What are the other benefits of an intra-aortic balloon pump?
↑ coronary perfusion.
Why would you not want to use an intra-aortic balloon pump on someone with aortic valve regurgitation?
During diastole as the balloon inflates blood will be pushed back into the LV due to a leaky aortic valve.
What is helium a byproduct of?
Oil and gas drilling
How does aortic stenosis affect coronary perfusion?
↓ coronary perfusion from ↑ in wall pressure.
Which valve issue will CPR have the least effect on?
Aortic Stenosis
Which graph represents aortic stenosis?
A
Which graph represents aortic regurgitation?
What is the hallmark sign based on the graph?
C
Decreased aortic diastolic pressure with widened pulse pressure.
Which graph represents mitral stenosis?
B
Which graph represents mitral regurgitation?
D
How does left atrial pressure in aortic stenosis compare to a normal heart?
Left atrial pressure will be elevated due to an increase in filling pressure.
How will mitral valve stenosis affect the pulmonary circulation and afterload of the right heart?
There will be increased fluid buildup in the pulmonary circulation and increased afterload of the right heart.
What are the factors that can affect pulse pressure?
Contractility (high contractility = increased pulse pressure)
Stroke Volume (increase SV = increased pulse pressure)
How will you compare the left atrial pressure of mitral valve regurgitation to a normal heart?
There will be retrograde blood flow to the left atrium during systole. This will increase LA pressure.
How will you compare the left atrial pressure of mitral valve stenosis to a normal heart?
There will be an increase in left atrial pressure due to the pressure it takes to move blood in the left ventricle.
Why can you hear a splitting of the 2nd heart sound?
How can you have exaggerated splitting of the 2nd heart sound?
Aortic and Pulmonary Valves closing at different times.
The aortic valve will typically close first and then the pulmonic valve will close second.
Inspiration will split S2 sounds. Inspiration will affect the right side of the heart and reduce preload and afterload. Inspiration will reduce pulmonary arterial blood pressure.
What is a co-dominance coronary artery?
Left circumflex artery and right coronary artery anastomose to form the posterior descending artery.
(43:55)
What is the A-wave?
Phase of cardiac cycle:
Mechanical event:
A-Wave
Phase of cardiac cycle: End of diastole (last ⅓ of filling)
Mechanical event: Atrial contraction
What is the C-wave?
Phase of cardiac cycle:
Mechanical event:
C-wave
Phase of cardiac cycle: Early systole
Mechanical event: Backwards “bowing” of valves in response to high ventricular pressures
What is the X-descent or x-wave?
Phase of cardiac cycle:
Mechanical event:
X-descent or x-wave
Phase of cardiac cycle: Mid systole
Mechanical event: Steep drop in pressure as atria relax and start filling.
What is the V-wave?
Phase of cardiac cycle:
Mechanical event:
V-wave
Phase of cardiac cycle: Late systole/ early diastole
Mechanical event: Rapid filling of the atria
What is the Y-descent or y-wave?
Atria filling the ventricles in early diastole
What is the H-wave or H-plateau?
Phase of cardiac cycle:
Mechanical event:
H-wave or H-plateau
Phase of cardiac cycle: Middle ⅓ of diastole.
Mechanical event: Diastolic plateau (not a lot of blood movement until atria contract to produce the c-wave)
An h-plateau occers immediately before the ________ wave.
a-wave
The x descent happens after the ________ wave
c-wave
The y descent happens after the ______ wave.
v-wave
What causes an overdamped waveform on an art line?
There is something stuck (air bubble) in the line between the pressure source (ie: the patient) and the transducer.
What causes an underdamped waveform on an art line?
The gain on the amplifier is set too high which will result in a lot of artifacts.
The main controller of our venous return is ___________.
Systemic filling pressure
(this will increase CO)
Spinal anesthesia will __________ the sympathetic chain.
How will this affect the CO/VR curve?
Inhibit the sympathetic chain
Decrease in CO and VR curve (decrease HR and vascular tone and decrease our PSF)
Change in which parameter will affect CO more:
Heart Pumping activity or Mean Systemic Filling Pressure (PSF)
Mean Systemic Filling Pressure (PSF)
What is the black dotted line representing?
This is a result of infusing a large amount of volume in the circulatory system. PSF increases, thus increasing CO to appx 13 L/min. The steeper slow also represents a decrease in RVR.
Describe what is going in the steep black, grey, and green lines.
An AV fistula will open up an additional pathway for blood to get back into the heart. Blood will move from the arteries to the veins with low resistance which will decrease RVR and increase CO.
What three priority tissues did Schmidt mention the body would try to maintain perfusion during shock?
Brain
Heart
Kidneys
What percent blood volume will need to be lost to affect cardiac output?
15% blood loss
Arterial pressure will start to be affected at 20% blood loss
What is allowing arterial blood pressure to maintain a pressure of 100 mmHg with 20% blood loss?
Sympathetic Nervous System
If the SNS is removed from the body, how much blood volume can you lose before it comes fatal?
10-15% blood volume
What are the early, middle, and last stages of shock called?
Early stage = non-progressive shock
Middle stage = progressive shock (can still be treated)
Last stage = irreversible shock (game over)
What are three problems that can decrease venous return?
- Lack of volume
- Lack of tone
- Obstruction in the VR pathway (clot)
(98:00)
What would the effect of bad cardiac output and low blood pressure on coronary perfusion?
Decrease coronary perfusion, which will result in the heart becoming a weaker pump
(99:37)
What two causes of cardiogenic shock were discussed in class?
- Myocardial Infarction that causes a decrease in the heart’s pumping ability. (Myocardial failure)
- Heart valve problems, resulting in a decrease in CO.
What will hypovolemic shock be attributed to?
Fluid loss
What will cause the extensive SVR decrease seen in anaphylactic and septic shock?
Vasodilator Release
Why does shock occur in neurogenic shock?
Lack of SNS capability
Which coronary arteries will be subjected to less wall stress?
Which coronary arteries will be subjected to higher wall stress?
Epicardial coronary arteries
Endocardial or Subendocardial arterial plexus (hardest coronary artery to perfuse, MI will most likely affect this area)
The deeper myocardial tissues tend to depolarize _______ and repolarize _________.
Depolarize first
Repolarize last
(The deeper we are, the longer the contraction is held)
What is this graph depicting?
Reduced Ventricular Compliance.
EDV is almost the same in the solid line and dotted line, but it takes a lot more pressure in one versus the other.
What are the causes of concentric LVH?
What are the causes of eccentric LVH?
Concentric LVH: Aortic stenosis and Chronic HTN
Eccentric LVH: Aortic/Mitral valve regurgitation, Ventricular septal defect, systolic dysfunction
What is the equation for ejection fraction?
EF = SV/ LV EDV
What is a normal EF for a healthy adult?
58.3% EF
(70/120) x 100 = 58.3%
Eccentric LVH is known as _____________ because the heart cannot produce enough pressure to get blood out of the heart to satisfy our metabolic use.
Systolic Heart Failure
Concentric LVH is known as ___________ because the ventricles will have trouble filling during diastole.
Diastolic Heart Failure
What medication can you use to slow down hypertrophic remodeling?
ACE inhibitor (growth factor inhibitor and it also reduces afterload)
Tetralogy of Fallot will result in a _________ to ________ shunt.
Right to left shunt.
Tetralogy of Fallot corresponds to anatomic stenosis of the pulmonary outflow tract in the right ventricle in combination with a ventricular septal defect. This results in a blockage of flow to the lungs with shunting of poorly oxygenated blood into the left ventricle and the systemic circulation.
