Cardiovascular Aging Pt. 1 Flashcards
what is the role of the cardiovascular system
to transport blood throughout the body
which ventricle of the heart has a thicker wall
te left ventricle
why does the left ventricle have a thicker wall
it exerts more force to pump blood through our entire systemic circulation
what could occur if the left ventricle wall gets too thick
lose the efficiency of contraction, and lose the efficiency of how much blood can fill into the chamber of our left ventricle
what remains the leading cause of morbidity and mortality in most societies
cardiovascular diseases
what is the strongest independent risk factor of CVDs
aging
what are the accelerating risk factors of CVDs
metabolic disturbances like (insulin resistance, high blood lipids, and obesity), hypertension and smoking/alcohol
why does aging increase CVD risk
due to effects of aging on the heart and aging of the vasculature
what are the effects of aging on the heart
molecular and cellular changes lead to structural and functional changes
what are the effects of aging on the vasculature
molecular and cellular changes lead to structural and functional changes
what do the structural and functional changes in the heart and vessels increase the risk of
- fibrosis, left ventricular hypertrophy, systolic and diastolic dysfunction
- chronic high BP
- arrhythmias, myocardial infraction, heart failure, and stroke
what are the cellular mechanisms of cardiovascular aging and increased CVD risk
- hypertension
- coronary disease
- stroke
- kidney disease
- cognitive impairment
- Alzheimer’s disease
- motor disorders, falls, exercise intolerence
whar are the normal effects of aging on the heart
- cardiomyocytes senesence andincrease cell death
- remaining functional myocyctes grow by hypertrophy
- fibrosis
-cellular aging - decreased sensitivity of response of sympathetic nervous system stimulation
- structural and functional consequences
what is fibrosis in the heart
increased number of fibroblasta that cause collagen deposits
what are the structural and functional consequences of normal effects of aging on the heart
- left side; ventricular hypertrophy and stiffening, atrial dilation
- slowed electrical conduction
- lower max heart rate
- diastolic dysfuntion
what is diastolic dysfunction
impaired relaxation of the left ventricle that results in slower and delayed left ventricle filling
what are the age-related vascular dysfunctions
- stiffening, thickening, and dilation of the large elastic artieries
- endothelial dysfunction
what is endothelial dysfunction largely due to
increased oxidative stress and increased expression of pro-inflammatory cytokines that result in chronic inflammation
what causes stiffening of the arteries
- elastin fibers degenerate
- increased collagen deposits
- protein cross-linking due to the formation of AGEs
- Ca2+ deposit buildup in wall
what occurs when theres thickening of the arterial walls
hypertrophy of vascular smooth muscle cells, and some cells migrate from the media to the intima layer and an increase in collagen in the intima
what is dilation of the arteries due to
degeneration of elastin (walls have lost their elastic integrity)
what happens to systolic blood pressure when major arteries become stiffer
systolic pressure will increase
what does arterial stiffness result in
an increase of systolic pressure
what are the effects of stiff arteries on pulse pressure
systolic pressure will increase, diastolic pressure will decrease, resulting in an increase of pulse pressure
what is an ejection wave
moving the pulse forward
what is a reflected wave
when a pusle moves backwords
what is the augmentation pressure determined by
the size and timing of the reflected wave and is a reflection of arterial stiffness
what does more stiff arteries equal to
higher augmentation
what is pulse wave reflection
the timing of reflected wave back to the heart depends in stiffness of the artieres
what is the relationship between younger artieres and the pulse wave reflection
younger arteries have more elastic that result in the reflected wave to be slow and reaches the heart during diastole
what is the relationship between older artieres and the pulse wave reflection
older arteries are stiffer resulting in the reflected wave to get back to the heart sooner during systole
what do stiffer arteries cause
a faster pulse wave
what is the augmentation index and pusle wave velocity
measures that correlate with arterial stiffness
how do you calculate pusle wave velocity
distnce/time
what is vascular endothelial dysfunction caused by
1) oxidatice stress which then increased expression of inflammatory mediators in the endothelial cells
2) excess production of ROS
3) decreased endothelial Nitric oxide (NO)
what is the result of when endothelial cells secrete endothelial nitric oxide
increase in vasodilation endothelin 1 causing vasoconstriction
what is reduced vasodilation in aging blood vessels due to
endothelial dysfunction
Ach stimulates the production of what
nitric oxide
when does the decline in endothelia function begin
around the 4th decade of life
when does the decline in endothelia function begin for women
around the 5th decade of life due to menopause
the rate of decline of endothelial function is greater in what sex with aging
greater in women than men
what happens to systolic blood pressure when arteries lose ability to vasodilate
systolic pressure will increase
what is mean arterial pressure governed by
cardiac output and the peripheral resistance modulated at the arterioles
what changes in blood pressure as a result of age-related vascular dysfunction
impaired nitric oxide response and stiffening of the large elastic arteries
what occurs during the impaired nitric oxide response
increased peripheral resistance that results in increased systolic pressure and diastolic pressure
what occurs during the stiffening of the large elastic arteries
an increae in systolic pressure and a decrease in diastolic pressure
how does tracking blood pressure with age happen
progressive increae in systolic blood pressure with age and an increase then decrease in diastolic blood pressure with age
what is progressive increae in systolic blood pressure with age due to
endothelial dysfunction and aortic stiffening
what happens to the left ventricle when there is an increased systolic pressure due to stiffer aorta
the left ventricle needs to work harder to eject blood and an increased afterload results in left ventricular hypertrophy
what are the effects of continued pressure overload on the heart
higher oxyegn demands on the heart and abnormal cardiac cycle
what are the peripheral consequences of increased systolic pressure
high pulse pressure that can damage fragile capillary beds, leading to microvascular disease
which organs are most at risk from high systolic pressure and why
1) kidney and brain due to their high resting blood flow
2) pulse-wave nephropathy resulting in kideny impairment, chronic kidney disease/failure
3) pulse-wave encephalopathy resulting in mircovascular brain damage, increased stroke risk and cognitive impairment/dementia
