Cardiac Output Flashcards
What is the equation for Cardiac output?
SV x HR = CO
What is the definition of cardiac output?
Volume of blood ejected from the hear per unit time
WHat is the normal value of CO?
5 L/min in resting adutlt
What is the Left Ventricular outflow tract?
The path that blood will forllow to get out of the heart
What is the Cardiac index?
Volume of blood ejected from the hear per unit time per unit of body surface area.
What is the normal value of Cardiac index?
3 L/Min/M2 body surface area
What is the consequence of a rupture of the chrodae tendinae?
Severe mitral valve regurgitation
What is the long term effect of regurgitant flow?
Clotting and erosion of the mitral valve
What is the definition of Stroke volume?
Volume of blood ejected by the ventricle during each contraction
What are the determinants of SV?
- EDV/preload
- Ventricular Contractility
- Afterload
What does the VEDV tell you?
Indicator of cardiac function and ventricular contraction
What are the determinants of VEDV?
BVol Venous Return Intrathoracic Pressure Effective atrial contraction AV valve function Ventricular compliance Pericardial condition Heart rate
What can effect the determinants of VEDV?
- BVol
- Venous Return
- Intrathoracic Pressure
- Effective atrial contraction
- AV valve function
- Ventricular compliance
- Pericardial condition
- Heart rate
- Hemmhorage, dehydration, IV infusion
- Position, Physical Activity
Strain Emphysema - A-V synchrony: AV block, A fib
- Mitral Stenosis
- Restrictive 6.Cardiomyopathy, MI
- Pericardial Effusuon, COnstrictive pericarditis
What is Cardiac Preload?
Tension exerted on the cardiac ventricular muscle when it begins to contract
What is Cardiac Afterload?
Pressure that the ventricle has to overcome to produce SV
What are the determininants of Afterload?
VOT: Hypertrophic Myocardiopathy
AVF:
PAR:
What are the determininants of EDV?
Preload, Ventricular Contrctility, after load
What is the ESV
Intraventricular volume at the end of systole
Tells you systolic function
What happens when preload increases with contractility and afterload stays constant?
SV increases as preload increases
What is the Frank Starling Law of the heart?
Length Dependant activation: Force of V contraction is a function of VED Length of the cardiac muscle
What is the Mechanism of the Frank Starling LAw?
Length of the Myocardial SarcomereDetermines its sensitivity to Ca2+
Waht are the implications of FSL?
Balance between two ventricles
inAdequate preload can cause a decrease in CO and HypoTN
Excessive initial Stretch May Result in Decompensation and Dec. in CO
What are the effects of Afterload on Stroke Volume keeping Preload and Contractility constant?
SV decreases with increasing afterload
What is the classical cause of increased afterload?
HTN