aging results in increased arterial stiffness (change in Extra Ccellular Mmatrix composition - decreased elastin, increased collagen deposition); ISH is responsible for 60-80% of HTN cases in patients > 60. Also, decreased compliance as a result of aging causes increased pulse pressure
Although everyone's arteries WILL get stiffer as we age, every single person will not develop coronary atherosclerosis and mitral stenosis. Will the valves become a bit stiffer? For sure! Will they develop "mitral stenosis"? No, that is not congruent with "normal aging".
"Isolated systolic hypertension, an elevation in systolic but not diastolic pressure, is the most prevalent type of hypertension in those aged 50 or over, occurring either de novo or as a development after a long period of systolicโdiastolic hypertension with or without treatment. The increase in blood pressure with age is mostly associated with structural changes in the arteries and especially with large artery stiffness."
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2805932/
its due to vascular scleorsis and stiffening- changes with aging- leads to high sys BP
decreased compliance of the vessels means you need to put more pressure in them to get flow. the stiffness/decreased compliance occurs with age- leading to an isolated increase in Systolic pressure.
submitted by โneovanilla(57)
The way I approached the question was to consider what happens 1. When you grow from a baby to a child, and 2. when you grow from a teenager to an older adult. Whatever remained true between both of them was the right answer.
Right answer: The resting BP of a newborn is 65/40 (google), while that of a 1-month old is 95/60. The average adult is higher, with the American Heart Association citing (absurdly, IMO) that "normal" is <120/<80. Nevertheless, the trend is that BP increases as we age, whether we are newborns or old people.
Wrong answers: Development of coronary atherosclerosis: Perhaps due to the American diet it can be argued that the development of atherosclerosis is almost inevitable as you become an older adult. Certainly not true as a baby --> child.
Development of mitral stenosis: Similar reasoning as coronary atherosclerosis; you MAY develop it as an adult (not nearly as common as a buildup of atherosclerotic plaques), but sure, let's say that it can happen. Not true as a baby --> child.
Increased basal heart rate: The opposite is actually true. The basal heart rate of a newborn can easily exceed 150, and that's considered normal. As we age, this heart rate goes down.
Increased cardiac muscle mass: This one was the hardest to work through. It is true that as we age from a baby --> child our heart grows in size. But if we tweak our assumption from before with the American diet, and instead put our patient on a more moderate diet, realistically his heart shouldn't increase in size too much, at least to the point of cardiomegaly.
Increased compliance of arteries: As we become older adults, the compliance of arteries decreases and stiffness increases (careful not to confuse arteries with lungs, which actually do increase in compliance as we age!)