Cardiac Cycle Flashcards
what is cyanotic congenital heart disease
less oxygen in systemic blood circulation
what is acyanotic congenital heart disease
normal oxygen level in systemic blood
examples of acyanotic congenital heart disease
- septal defect (incomplete septum development= o2/de02 mix)
- coarctation of aorta (aorta narrows, l. ventricle pushes harder= higher bp.)
- patent ductus arteriosus
examples of cyanotic congenital heart disease
- tetraology of fallot
- less blood in pulmonary circuit, less oxidised blood= blue body
divided into 4 defects
- ventral septal defect
- over riding valve
- stenosed pulmonary valve
- enlarged right ventricle
what is early ventricular systole
where ventricles= iso-volumetric contraction
what is iso-volumetric contraction
ventricles CONTRACT BUT pressure lower than atrial pressure
semi-lunar valves shut
NO change in blood volume
what is iso-volumetric relaxation
ventricles RELAX BUT pressure higher than atrial pressure
AV valves shut
NO change in blood volume
what is the di-crotic notch
when high pressure causes the elastic arterial walls to recoil there is a small and temporary rise seen
what is meant by venous return
all the blood returning to the heart from systemic and pulmonary circulation. this blood passes through the AV valves under own pressure
what causes heart sounds (auscultation)
the turbulent rush of blood through valves as they CLOSE
1st lub sound is caused by…
AV valves close (phase 2- start of systole)
2nd dup sound is caused by…
semi-lunar valves close (phase 4- start of diastole)
what does blood pressure measure
the AORTIC pressure
what is meant by diastolic pressure
the lowest blood pressure recorded in diastole
what is meant by systolic pressure
the highest blood pressure recorded in systole
what is mean arterial pressure, MAP
MAP= the average AORTIC pressure across the whole cardiac cycle MAP= DP + (PP/3)
how do you calculate MAP, and why is not a simple average
MAP= DP + (PP/3)
Not simply an average of the 2 pressures because aortic bp. is closer to diastolic value than systolic when averaged out
how do you calculate pulse pressure, PP
PP= SP-DP
how do you calculate SV
EDV- ESV
what is EDV
maximum amount of blood in ventricles
what is ESV
the blood left -over in ventricles AFTER they have contracted
how do you calculate ejection fraction
EF= SV/ EDV
what are the 3 stages of coronary heart disease
- endothelial dysfunction (increase in adhesion mols, chemokines, tissue factor, and decrease in endothelium-dependant vaso-dilation )
- fatty streaks develop (in the wall of artery under endothelium), stimulates the vascular smooth muscles to migrate to fatty acids, proliferate
- inflammatory response activated (increase in macrophages, T-cells, necrotic lipid core, tissue factor, plaque vulnerability and plaque thrombogencity)
how do you treat coronary heart disease
angioplasty: CABG, PTCA
CABG= use of saphenous vein from leg
PTCA= use of a stent
