Heart Pump Flashcards
An increase in heart rate is described as this type of effect
positive chronotropic
An increase in the rate of action potential conduction is called this
positive dromotropic effect
An increase in cardiac contractility is called this
positive inotropic effect
An increase in rate of cardiac relaxation is called his
positive lusitropic effect
Most efficent way to achieve CO
Low HR and High SV
What needs to happen for the aortic valve to open?
Pressure in the left ventricle must exceed that of the aorta
Describe the Isovolumetric Contraction Phase
Period between the mitral valve closure and aortic valve opening in which chamber is closed with fixed volume
What differs between the Left and Right heart?
Magnitude of peak systolic pressure is lower due to lower resistance in lungs
S1 sound produced by this
Closure of AV valves
S2 sound produced by this
Closure of aortic and pulmonary valves
Describe preload
End diastolic pressure/volume that stretches the ventricle to its greatest dimensions
Increasing the preload has what effect on the stroke volume and muscle length?
Increases volume and causes more shortening
describe afterload
tension or stress that develops in the cardiomyocytes of the left ventricle during ejection/contraction
List some things that increase myocardial O2 demands
increase HR, diastolic filling, cardiac contractility, arterial pressure
An increase in cardiac preload has what effect on SV and wall tension?
Increase both, but does not change end systolic volume
