Determinants of CV Performance- CardioRush

Mitral valve open, blood flows from LA to LV, aortic valve closed
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Terms in this set (83)
Mitral valve open, blood flows from LA to LV, aortic valve closed
In a normal heart, what is the state of the left ventricle and valves in diastole?
Mitral valve closed, aortic valve open, blood flows from LV to aorta
In a normal heart, what is the state of the left ventricle and valves in systole?
False (dependent)
True or false: pressure and volume are constantly change in the cardiac cycle, but independent of each other
Ventricular loading, atrial systole, isovolumetric contraction, rapid ejection, isovolumetric relaxation
What are the phases of the cardiac cycle on the pressure volume loop?
Ventricular loading
What is 4?
Image: Ventricular loading
Atrial systole
What is 3?
Image: Atrial systole
Isovolumetric contraction
What is 2?
Image: Isovolumetric contraction
Rapid ejection
What is 1?
Image: Rapid ejection
Slow ejection
What is 6?
Image: Slow ejection
Isovolumetric relaxation
What is 5?
Image: Isovolumetric relaxation
ESPVR, EDPVRWhat 2 slopes define the upper and lower boundaries of the pressure volume loop?Mitral valve opens when LA pressure > LV pressureWhen does ventricular filling begin?False (large change in volume, little change in pressure)True or false: during ventricular filling, the pressure will increase greatly as volume increasesSystole with closed valvesWhat begins the isovolumetric contraction stage of the pressure volume loop?Opening of aortic valveWhat causes the rapid ejection phase of the pressure volume loop?IncreasesWhat happens to the pressure during the rapid ejection phase of the pressure volume loop?ESPVR is reachedWhen does the pressure stop increasing during the rapid ejection phase of the pressure volume loop?False (everyone has a different, unique shape)True or false: all healthy hearts have the same PV loop shapeHeart health and characteristicsWhat does the shape and size of the PV loop for an individual depend on?Preload, afterload, contractility, distensibilityWhat are the 4 main determinants of cardiac performance that shape a PV loop?EDPWhere on the PV loop can you find the value for preload?ESPWhere on the PV loop can you find the value for afterload?Slope of ESPVRWhere on the PV loop can you find the value for contractility?EDPVRWhere on the PV loop can you find the value for distensibility?Compliance or stiffnessWhat value can be found along the line defined by the EDPVR?TrueTrue or false: compliance is inversely related to stiffnessdV/dP on EDPVR curveHow is compliance calculated?dP/dV on EDPVR curveHow is stiffness calculated?Healthy hearts work in compliant area, diseased in stiff areaWhat is the difference in where a heart operates on the EDPVR curve if it is healthy vs. diseased?SmallWhat is the change in pressure for a large change in volume in an area of the EDPVR curve that is compliant?PreloadWhat is the term for the force which fills the heart at the end of diastole?Wall stress at the end of diastoleWhat does preload in the heart measure?Pr/2hHow is wall stress calculated?Decrease radius, increase thicknessWhat can the heart do to adapt to an increase in wall stress?More sarcomere to share the forceWhy does an increase in wall thickness decrease the wall stress?increase in preload causes increase in SVWhat is the relationship between preload and stroke volume?False (only to a certain point, then actin and myosin don't overlap enough to generate more force)True or false: an increase in preload will always lead to an increase in SVA small increase in preload will greatly increase SVWhy is it said that the healthy heart is preload dependent?Wall stress in systoleWhat does afterload in the heart measure?ESPWhat point on the PV loop shows afterload?DecreasesWhat is the effect of an increase in afterload on SV?A small change in afterload doesn't change SV muchWhy is the normal heart said to be afterload independent?ContractilityWhat is the term for the ability of the heart to contract with a given force and rate?dP/dV on ESPVRHow is contractility calculated?IndependentWhat is the relationship of contractility to preload and afterload?Conditions in myocytesWhat determines contractility since it is independent of preload and afterload?EchoWhat clinical measurement do we use to evaluate contractility?Stroke volumeWhat is the term for the volume of blood pumped from the heart after each contraction?IncreasesWhat is the effect of an increase in preload on stroke volume?DecreasesWhat is the effect of an increase in afterload on stroke volume?EDV-ESVWhat is the equation to calculate stroke volume?HR, Synergy of contractionOther than preload, afterload, contractility, and compliance, what 2 factors influence cardiac performance?False (HR affects SV, and HRxSV=CO)True or false: as HR increases, CO will always increaseLess time for filling in diastole, less preload (EDV decreases)Why does an increase in HR cause a decrease in SV?TrueTrue or false: increasing HR results in an increase in the contractility of the heart slightly, but also decreases SV, so CO will start to decline after a maximal pointAtria and ventricles, L and R ventriclesWhat are the 2 things that need to be in synchrony for the heart to contract efficiently?20%What percentage of total CO does the atrial kick contribute at the end of diastole?Purkinje fibersWhat does interventricular synergy require to be intact?Increase HR or SVWhat are the ways the body can increase CO?Increase preload or contractility, decrease afterloadWhat are the ways the body could increase SV?Increase CO, increase O2 to tissues, redistribute blood flowWhat does the body do during exercise to pull from the cardiac reserve to meet tissue needs?Increase EDVWhat variable will cause an increase in ONLY preload?Increase ESVWhat variable will cause an increase in ONLY afterload?TrueTrue or false: a large increase in afterload only causes a mild increase in ESVIncrease preloadWhat does the heart to do compensate in almost all situations that result in decrease SV?Afterload causes higher ESV, increase in preload causes higher EDV, EDV-ESV=SVHow does increasing preload compensate for an increase in afterload?Contractility is slope of ESPVR, decrease causes higher ESV, increased preload increases EDVHow does increasing preload compensate for a decrease in contractility?Lower distensibilty is steeper slope of EDPVR, lower EDV, preload increases EDVHow does an increase in preload compensate for a decrease in distensibiltiy?False (usually works in mild cases, but not as disease progresses)True or false: an increase in preload usually works to compensate in cases of more severe heart diseaseHeart keeps trying to increase preload, but goes too farWhy does heart disease result in congestion of vessels?TrueTrue or false: with progressive cardiac disease, the cardiovascular reserve is increasingly used up, even at restIndependentWhat is the dependence on preload in a diseased heart?Change in PV loop position causes changes in preload to not change SV or COWhy is a diseased heart preload independent?DependentWhat is the dependence on afterload in a diseased heart?Change in PV loop position causes changes in afterload to change SV and COWhy is the diseased heart afterload dependent?False (cannot increase preload without being in congestion)True or false: Because of the Frank Starling curve of a diseased heart, you can usually increase preload to be within limits for normal CO without being in congestionTrueTrue or false: Because of the Frank Starling curve of a normal heart, you can usually increase preload to be within limits for normal CO without being in congestionEccentricWhat type of hypertrophy occurs when the overall size of the heart increases, and chamber size dilates?Aortic/Pulmonic regurg, mitral/tricuscpid regurg, DCMWhat diseases cause eccentric hypertrophy of the heart?ConcentricWhat type of hypertrophy occurs when the overall size of the heart remains the same, but chamber size decreases?Aortic/pulmonic stenosis, HCMWhat diseases result in concentric hypertrophy?Pressure overloadWhat causes concentric hypertrophy: pressure or volume overload?Volume overloadWhat causes eccentric hypertrophy: pressure or volume overload?