Term
| why does the left ventricle have more muscle mass? |
|
Definition
| it pumps against four times the pressure the right ventricle does |
|
|
Term
| where does the blood pump to from the left ventricle? |
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Definition
|
|
Term
| where does the blood pump from the right ventricle |
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Definition
|
|
Term
| blood pressure in the aortic arch (#) |
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Definition
|
|
Term
| blood pressure in the pulmonary artieries (#) |
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Definition
|
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Term
|
Definition
| aortic valve, pulmonary valve |
|
|
Term
| atrio-ventricular valves (2) |
|
Definition
| mitral/bicuspid valve, tricuspid valve |
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Term
|
Definition
| between left atrium and left ventricle |
|
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Term
|
Definition
| between right atrium and right ventricle |
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|
Term
| initiation point of electrical signal in the heart |
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Definition
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Term
|
Definition
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Term
|
Definition
| between right ventricle and right atrium |
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Term
|
Definition
| bundle of His break apart into individual fibers that carry the electrical signal that tells the ventricles to contract |
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Term
|
Definition
| depolarization of the myocardium (atrium) |
|
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Term
|
Definition
| contraction of the ventricular muscle |
|
|
Term
| where on EKG is repolarization of atrium? |
|
Definition
| hidden by the QRS complex |
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Term
|
Definition
| repolarization of ventricle |
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|
Term
| coronary artery supplies blood to.... |
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Definition
|
|
Term
| circumflex vessel, location and what does it supply? |
|
Definition
| wraps around the heart, supplies myocardium (except not so much left ventricle) with blood |
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|
Term
| when is coronary flow higher? systole or diastole? |
|
Definition
|
|
Term
| where do coronary arteries originate? |
|
Definition
|
|
Term
| what happens to coronary arteries in systole? |
|
Definition
| pressure and resistance increase, vessels almost close |
|
|
Term
| what happens to coronary arteries in diastole? |
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Definition
| pressure decreases, but so does resistance, and flow increases |
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Term
|
Definition
| closed loop diagram describing the pressure and volume changes of the heart |
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Term
|
Definition
| contraction of the ventricles without any increase or decrease in volume |
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Term
|
Definition
| systolic contraction, release of blood into aortic arch |
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Term
|
Definition
| diastole, the ventricles are relaxing, but no volume is entering - atrio-ventricular valves are still closed |
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Term
|
Definition
| physical work done by the chamber during contraction |
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Term
|
Definition
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Term
|
Definition
|
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Term
|
Definition
| velocity in which the heart muscles contract |
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|
Term
| effect of increased HR on stroke volume |
|
Definition
| can decrease stroke volume, not enough time to fill |
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Term
|
Definition
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Term
|
Definition
|
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Term
|
Definition
|
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Term
|
Definition
| ventricular bypass, prone to clogging, temporary assist device |
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Term
| Mechanical Auxiliary Ventricle |
|
Definition
| device is relaxed during systole, contracted during diastole, used the concept of counter pulsation or diastolic augmentation, not used anymore, must be monitored with EKG and with every cardiac cycle |
|
|
Term
| diastolic augmentation/counter pulsation |
|
Definition
| device is relaxed during systole, blood can flow freely through aorta, closes up during diastole, forcing blood back into aortic arch. Blood stopped by semilunar valve, but it forced into the coronary arteries, supplying the weakened heart a larger blood supply, reduces amount of work heart has to do |
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Term
| Intra-aortic balloon pump |
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Definition
| uses concept of counter pulsation or diastolic augmentation, balloon in aortic arch or large arteries, inflates during diastolic to feed coronary arteries |
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Term
| insertion location of intra-aortic balloon pump |
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Definition
|
|
Term
| why don't drugs work in cardiac failure? |
|
Definition
vasodilators - decrease resistance, but perfusion plummets
vasoconstrictors - increase pressure, increase flow, but you make a weak heart work harder |
|
|
Term
| why did the cannula - diastolic augmentation technique fail? |
|
Definition
| hemolysis of red blood cells, when moving that fast through a small opening, they get torn apart and aren't functional |
|
|
Term
| series cardiac assist devices |
|
Definition
| diastolic augmentation, ventricular bypass |
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Term
| external counter pulsation |
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Definition
| suit that covers bottom half of patient, decrease and increase pressure with the heart cycle |
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Term
|
Definition
| put a device around aorta, compress and release - can cause rupture and other damage to the aorta |
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Term
|
Definition
| body acceleration sync with heart - accelerates body with cardiac cycle, developed in holland, liked because it was non invasive..... |
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|
Term
| refractory ventricular failure |
|
Definition
| failure that does not respond to medications |
|
|
Term
|
Definition
| clinical phenomena - sweating, urinary output down, pulse bad |
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|
Term
|
Definition
|
|
Term
| indication of heart failure/need of assist device |
|
Definition
refractory ventricular failure
cardiogenic shock
unstable refractory angina
impending infarction
mechanical complicatsion ue to infarction
ischemia related intractable ventricular arrhythmias
septic shock
angiography/angioplasty patients |
|
|
Term
| reasons you can't get an assist device |
|
Definition
aortic insufficiency - counter pulsation will go through valve, damaging
aneurym - weakened walls of aorta, increased pressure could burst the walls
calcification - vessel is fragile and can break |
|
|
Term
| reasons sheathless insertion of balloon assist device cannot be done |
|
Definition
severe obesity
scarring of the groin |
|
|
Term
| why do we increase diastolic pressure |
|
Definition
| to increase coronary perfusion |
|
|
Term
| dangers of increasing end diastolic pressure |
|
Definition
| in effort to counter the weak contractions, the heart tries to increase the troke volume of the heart by filling it more. this larger fill can stretch the heart to the point where the interaction between the actin and myosin can no longer happen |
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|
Term
| what happens at the dicrotic notch? |
|
Definition
| aortic valve loses, diastole begins |
|
|
Term
| what peak increases in the cardiac pressure waveform when diastolic augmentation is utilized? |
|
Definition
| diastolic peak is increased to well above the pressure in the systolic peak |
|
|
Term
| what is the relationship between balloon assist device location and functionality |
|
Definition
| direct - the closer it is the the heart, the more effective it is |
|
|
Term
|
Definition
| phasing means syncing the function of the device up with the cardiac cycle, often times special algorithms are used to predict the changing of the heart rates |
|
|
Term
| why don't these devices work as well in patients with healthier hearts |
|
Definition
| the healthier the heart, the more capable it is to make compensatory changes, will try to correct the increased diastolic pressure |
|
|
Term
| benefits of diastolic augmentation assist device |
|
Definition
reduce oxygen comsumption of left ventricle - not working as hard
increase oxygen availability |
|
|
Term
| navier - stokes and continuity equations |
|
Definition
fr incompressible fluids - newtons second law
needed to analyze the blood flow |
|
|
Term
| inflation/deflation time vs. oxygen availability graph |
|
Definition
| surface graph - peak/highest point on the graph is highest oxygen availability |
|
|
Term
| inflation/deflation time vs. oxygen consumption graph |
|
Definition
| surface graph - peak/highest point on the graph is highest oxygen consumption |
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|
Term
| desired relationship between oxygen availability and oxygen consumption |
|
Definition
| highest oxygen availability, and lowest oxygen consumption -- min and max do not occur at the same moment, develop an algorithm to optimize relationship |
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|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| why is an MDP PSP graph used instead of Oa and Oc? |
|
Definition
| easier to measure pressure than oxygen availability |
|
|
Term
|
Definition
constants used to normalize MDP and PSP values, then values are subtracted to find a performance index.
I = K1*MDP - K2*PSP |
|
|
Term
| oxygen vs. contractility graph -- unassisted vs. assisted |
|
Definition
| unassisted, there is oxygen deficit, assisted, there is larger reserve of oxygen |
|
|
Term
| role of contractility in reserve volume of oxygen |
|
Definition
| the lower the contractility, the lower the reserve |
|
|
Term
|
Definition
| narrowing of blood vessels |
|
|
Term
| in series assistance increases crossover point between what and what? |
|
Definition
| oxygen availability and oxygen consumption - moves point to the left - higher Oa at lower contractility |
|
|
Term
| inflation of balloon at end systole maximizes and minimizes what? |
|
Definition
| maximizes SV, Voa; minimizes Voc |
|
|
Term
|
Definition
| BYPASS the ventricle - ventricle has to pump less hard -- pumps from atrium to the aorta |
|
|
Term
|
Definition
| left ventricular assist device |
|
|
Term
| in series vs. parallel assist devices |
|
Definition
heart must retain pumping ability for in series
in parallel, pump does nearly all work of the heart |
|
|
Term
| parallel assist effects on coronary arteries |
|
Definition
| not as much blood pumped into coronary arteries, but not as necessary, due to relieving heart of much work |
|
|
Term
| in parallel assist, is the ventricle expected to recover? |
|
Definition
|
|
Term
| exterior device - location, pros/cons |
|
Definition
| device in abdomen, lines go from outside of the body to inside, risk of infection |
|
|
Term
| interior device - location, pros/cons |
|
Definition
| device in abdomen, internally supplied, foreign object attack, immune system response |
|
|
Term
| why don't parallel assist devices have to be synced to the heart? |
|
Definition
| heart works so feebly to begin with, not necessary |
|
|
Term
|
Definition
| 1950's artificial heart in animals (air pump) |
|
|
Term
| first implantation in human - TAH, pros/cons |
|
Definition
total artificial heart - intended as a bridge to transplantation
patient lived for two days - died of stroke |
|
|
Term
|
Definition
enormous concept next to the bed
air pumped heart
barney clark - survived 112 days |
|
|
Term
|
Definition
| first recipient of the Penn State Heart |
|
|
Term
| Abiocore Artificial Heart |
|
Definition
|
|
Term
| why didn't cannulation work? |
|
Definition
|
|
Term
| LVAD implant approved by FDA |
|
Definition
|
|
Term
| non-pulsatile implant properties |
|
Definition
centrifugal, axial flow
necessary properties:
small, simple design, no valves, longer life, less invasive surgery, electrically driven, smaller transcutaneous lines |
|
|
Term
| non-pulsatile implant complications |
|
Definition
| bleeding, thromboembolism, increased gastro-intestinal bleeding, inreased platelet damage, hemolysis, ventricular arrythmia |
|
|
Term
|
Definition
first LV assist device, 1966
three tubes, one afferent, one efferent, and one pumps the diaphragm |
|
|
Term
|
Definition
| parallel assist device, external air power supply, pneumatic |
|
|
Term
|
Definition
| first generation pneumatic pump |
|
|
Term
|
Definition
| inserted into the left ventricle, draws blood from LV and into aorta, INSIDE THE BODY |
|
|
Term
|
Definition
| improved from jarvik 7, transcutaneous connection to battery power |
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|
Term
|
Definition
|
|
Term
|
Definition
| internal rechargeable battery, external coil and implanted coils right underneath the skin |
|
|
Term
|
Definition
made of titanium and stainless steel
inflow - LV
outflow - aorta |
|
|
Term
|
Definition
| cannul from bottom of the ventricle, pumped up probe to the aorta |
|
|
Term
|
Definition
minimal surgery - placed endovascularly
implantable control and battery - increase pump efficiency, eliminate transcutaneous wires
pulsatile or continuous flow?
automatic speed control
preventing retrograde flow during weaning - can lead to rapid patient deterioration |
|
|
Term
| Medtronic tilting disc valves |
|
Definition
| failed, caused thromboembolism, in jarvik 7 |
|
|
Term
|
Definition
| survived on Jarvik 7 for 620 days |
|
|
Term
| Dr. Alain Carpentier artificial heart |
|
Definition
| made of animal biosynthetic tissues, ventricles are equipped with micropumps |
|
|
Term
| benefits of non-pulsatile hearh |
|
Definition
| simpler, smaller, more reliable, no need for valves - less RBC damage, lower energy requirement, easier to implant |
|
|
Term
|
Definition
10 liters/min flow rate
70-120 bpm
accelerate blood from 0-25 lpm on one beat
pump against 120mmHg
filling pressure 20mmHg |
|
|
Term
| design requirements LV assist |
|
Definition
10 years or more
must operate continuously
maintenance free
components small and strong
efficient
power - implantable of delivered across skin
responsive to biological demands |
|
|
Term
| anatomical considerations |
|
Definition
must operate in adults and children
stable, no corrosion
no degradation in emzymatic attack
capable of being joined to flexible anatomy
must not damage anatomical structures
anatomy must be able to support the heavy device |
|
|
Term
|
Definition
| not used anymore - ball covers opening in diastole, caused clotting and hemolysis, disruption of flow |
|
|
Term
| Magovern-Cromie sutureless valve |
|
Definition
| small hooks around the rim angled to the side - lowers valve into plae |
|
|
Term
|
Definition
| shrinking the size of the ball in the valve - decrease obstruction of ball, smaller cage on other side to make sure ball goes through the valve back |
|
|
Term
| single leaflet disc valves |
|
Definition
| worse than ball valve, disrupted flow more |
|
|
Term
|
Definition
| tilting disc valve with a single disk - held in place by an inflow and outflow strut |
|
|
Term
|
Definition
| developed cracks, struts would fail and disk would separate and create an embolism |
|
|
Term
|
Definition
| poor test results in the US, two flaps that pivot on a hinge |
|
|
Term
|
Definition
silicone rubber
silicone carbide
pyrolitic carbion |
|
|
Term
|
Definition
animal tissue valves - porcine or bovine
non valve tissue bovine pericardium
stentless
human tissue valves
from another person
or autograft - take pulmonary valve to use as a replacement |
|
|
Term
|
Definition
| hancock valves (porcine) standard and modified, carpentier-Edwards valves |
|
|
Term
|
Definition
| single pig valve sewm onto plastic stent |
|
|
Term
|
Definition
| composite of two porcine valves |
|
|
Term
|
Definition
ionescu-shiley, hancock, carpentier-edwards - securing pericardial tissue to the stent to avoid high stress regions that lead to tears
aortic valve - pericardial sac |
|
|
Term
|
Definition
| eliminate space taken up by stent |
|
|
Term
|
Definition
pros:
excellent hemodynamics
decrease in thickness of heart
cons:
more difficult to implant
requires special measurements
no data on durability |
|
|
Term
|
Definition
| valve transplanted form another person |
|
|
Term
|
Definition
| transplanted from one position to another within the same person |
|
|
Term
|
Definition
| pulmonary valve to replace aortic valve |
|
|
Term
|
Definition
| infection of the heart muscle |
|
|
Term
|
Definition
| heart rhythm disorder - partial block in AV node, slows heart rate, depolarization signals slow to 30-40 bpm |
|
|
Term
|
Definition
| signal does not get from atrium to ventricle |
|
|
Term
|
Definition
|
|
Term
|
Definition
| atria fibrillation - not as deadly |
|
|
Term
|
Definition
| ventricular fibrillation - cannot survive for very long |
|
|
Term
| pacemaker original design |
|
Definition
| for people with complete heart block, fixed rate |
|
|
Term
|
Definition
| one lead, titanium case is used as other electrode |
|
|
Term
| pacing cells - killing a group of cells. How/why? |
|
Definition
| current density diminishes, has to travel further. If it decreases, increase the amplitude. ALSO additional drain of battery |
|
|
Term
|
Definition
Chamber paced, first letter
V,A,D (ventricle, atrium, dual)
Chamber Sensed
V,A,O (ventricle, atrium, none)
Mode of Response
T,I,O (triggered, inhibitied, none) |
|
|
Term
|
Definition
Addition of programmable functions
R,C,M,P,O (rate modulated, communicating, multiprogrammable, simple programmable, none)
Antitachycardia functions
P,S,D,O (paced, shocks, dual, none) |
|
|
Term
| communicating letter code |
|
Definition
| atria and ventricles synchronized |
|
|
Term
|
Definition
| lose 10% of blood flow of atrium |
|
|
Term
|
Definition
| SA node not functioning correctly, AV node is fine |
|
|
Term
|
Definition
| pace atrium and ventricle in sync |
|
|
Term
|
Definition
| if signal, no pacing, if no signal, paces |
|
|
Term
|
Definition
|
|
Term
|
Definition
amplitude
duration
refractory period
atrial sensitivity
pacing rate
AV delay
pacing mode |
|
|
Term
|
Definition
zinc mercury cells - projected to last for 5 year, lasted for 2
current: lithium iodide
10-12 yrs life
future:
biological batteries |
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|
