Determineants Of Cardiac Pump Function Flashcards
According to Frank-Starling, How will Ventricular filling pressure (preload) affect volume?
Increase preload will increase ventricular volume progressively and become constant and larger
What is the Frank-Starling law of the heart?
large increases in volume happen with
only small increases in pressure.
How does Venous return affect the heart?
Venous Return Affects right atrial pressure, stroke volume, and CO
What factor does TPR affect?
Only Cardiac output
What are the main regulators of myocardial performance?
Ventricular receptors: Stimulated by reduced ventricular filing column w/ strong ventricular contraction
Standing: Ventricular filling is diminished due to pooling in vein
What is contraction frequency?
Initial cardiac contractility is every 20 seconds.
What does the mechanical restitution curve represent?
Strength of a premature beat in relation to the coupling interval
Describe Ventricular Hypertrophy
- Diastolic dysfunction
- Ventricle greater force and higher pressure
- Increased ventricle thickness
- reduced compliance
Describe eccentric hypertrophy.
- Systolic dysfunction
- Chamber radius increased
- Wall thickness INC moderately
- Volume + Pressure overload
What is the major cause of atrial hypertrophy?
- Increased afterload
- Ex. Mitral valve stenosis
- Increases resistance to blood flow across the valve which requires greater pressure in left atrium to drive filling. Pressure afterload stimulates wall thickening in left atrium.
What is athletic heart syndrome
• No family history
• Sinus bradycardia and arrhythmia, atrioventricular block,
incomplete RBBB, isolated LVH
What is characteristic of Aortic Stenosis?
• Increased left ventricular pressure
• Increased end systolic volume
• No change in end diastolic volume
• Decreased stroke volume
• Ventricular hypertrophy leads to decreased
ventricular compliance and increased end diastolic
pressure for given end diastolic volume
Describe Mitral regurgitation
• No true isovolumetric phase
• Decreased end systolic volume due to decreased
resistance and increased regurgitation into left atrium
during systole
• Increased end diastolic volume due to increased left
atrial volume/pressure from regurgitation results in
increased ventricular filling
• Increased stroke volume
• Increased pulse pressure
What is characteristic for Aortic regurgitation?
- No true isovolumetric phase
- Increased end diastolic volume
- Increased stroke volume
- Increased pulse pressure
What is characteristic of Mitral Valve stenosis?
• Increased left atrial pressure • Decreased end diastolic volume because of impaired ventricular filling • Decreased end systolic volume • Decreased systolic volume
