CV Flashcards
primary function
bringing O2 and nutrients to organs and transporting CO2 and other waste products for removal
myocardium + age-related changes
- scaffolding of the heart chambers
- decreasing cardiac contractility
- more time for diastolic filling and systolic emptying
- less responsive to SNS
> > fight, flight, freeze
myocardium + age-related changes
–electrophysiology decline
- less pacemaker cells
- irregularity in shape of pacemaker cells
- increased deposits of fats, collagen, and elastic fibers around SA node
vasculature: age-related changes
- changed in tunica intima and media
> > endothelial cells become - irregular in size/shape - diameter of lumen of aorta increases to compensate for arterial stiffening
- veins become thicker, more dilated, less elastic
- increased vascular resistance > > increase in systolic BP
vasculature: age-related changes
- increased peripheral resistance diminishes ability to increase blood flow to vital organs
- due to peripheral resistance the LV is
forced to work harder and becomes larger and
thicker - valves of large leg veins become less efficient in
returning blood to heart
Baroreflex Mechanism
receptors in aortic arch and carotid artery
physiologic process that regulates BP
- BP high, baroreceptor send signal to brain
- brain sends cardiac inhibitory signal to heart or blood vessel to decrease
sympathetic response (ie. lower the HR, lower the CO and decrease resistance) and lower the BP
Baroreflex Mechanism-Age
Related Changes
- decreased compensatory responses in both hyper/hypo stimuli
- Baroreceptors in large arteries less effective in controlling BP
> > postural changes
Consequences of Age-Related Changes
- decreased adaptive response to exercise
- slightly lower HR
^ susceptibility to hyper AND hypo
^ susceptibility to arrythmias (i.e., atrial fib) - decreased cerebral blood flow
Pathological Risk
Factors Affecting
Cardiovascular
Function
- Arrhythmias
- Heart Failure
- Myocardial Infarction (MI)
- Peripheral Vascular Disease (PVD)
- Venous Thromboembolism (DVT or PE)
- Stroke (aka CVA)
- Transient Ischemic Attack (TIA)
- Atherosclerosis
NOTE: Most CV disease is preventable through
interventions to reduce risk factor
atherosclerosis
def: disorder of the medium and small arteries in which deposits of lipids and atherosclerotic plaques reduce or obstruct blood flow
- atherosclerotic changes begin in childhood and can progress to plaque formation
- plaque lesions can rupture (causing acute
events) OR remain stable and continue to grow (causing chronic disease
modifiable risk factors
– physical inactivity
def: <30 mins of moderate physical activity 5x/ wk or <20 mins of vigorous physical activity 3x/ wk
- older adults often have compounding conditions making reaching these goals difficult
- any physical activity reduces the CV disease risk
modifiable risk factors
– smoking + 2nd-hand smoke
- all exposure to smoking increases risk of CV disease
and mortality - on avg. both M and F smokers reduce their life expectancy by 13-15 years
- non-smokers exposed to second-hand smoke ^ their risk for developing Coronary Artery Disease (CAD) by 25-30%
modifiable risk factors
– dietary habits
- high intake of saturated fats increases risk of CV
disease - intake of 2.5 servings of whole grains/ day associated with 21% reduction in CV disease
- intake of 1-2 servings of oily fish/ week lowered risk of CV disease by 36%
- each daily serving of fruit/ veg associated with 4%
reduction in CAD and 5% reduction in stroke - low sodium intake associated with at 25% reduction in CV disease after 10-15 yrs follow-up
obesity
BMI 30 kg/m2 <
hypertension (HTN)
risk factors:
- age
- ethnicity
- heredity
- weight
- physical inactivity
- psychosocial stressors
- sleep apnea
- low education
- low socioeconomic factors
