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age-associated changes in cardiovascular function

Cardiovascular function declines with age Physiology: 1) decreased inotropic & chronotropic responses a) diminished response to orthostasis b) decreased baroreceptor sensitivity c) diminished beta-adrenergic responsiveness d) stress-induced increase in LV ejection fraction & cardiac index is blunted, but responsive to training 2) increased afterload resulting from a) changes in proximal arteries > distal arteries 1] elongation & tortuosity of arteries, including aorta 2] increased intimal thickening of arteries 3] increased fibrosis of media of arteries - fragmentation of elastin in media 4] subendothelial layer thickened with connective tissue 5] increased arterial stiffness 6] irregularities in endothelial cells b) increased peripheral vascular resistance 1] peripheral vasculature constriction is maintained 2] diminished peripheral vasculature relaxation a] impaired beta-adenergic mediated vasorelaxation b] vasorelaxation to other vasodilators may be intact c) increased systolic blood pressure 3) increased afterload results in LV diastolic dysfunction a) increased LV mass b) decreased mycocardial relaxation & compliance c) diminished early diastolic filling d) increased late diastolic filling e) end diastolic volume is decreased f) left atrial hypertrophy g) increased prevalence of S4 reflecting left atrial contraction into a noncompliant left ventricle [7] 4) diastolic blood pressure tends to peak in midlife 5) increased contraction duration - reduced myocardial contractility [5] 6) decreased heart rate variability 7) decreased response to exercise a) decreased maximum heart rate - refractory to training - unchanged resting heart rate b) decreased maximum cardiac output c) decreased VO2 max, responsive to training d) diminished coronary blood flow e) diminished peripheral vasodilation 8) decreased intrinsic sinus (SA node) rate - loss of pacemaker cells in SA node 9) decreased cardiac conduction velocity a) through the AV node b) through the His Bundle & bundle branchers 10) increased refractoriness to electrical stimulation 11) decreased beta-adrenergic-mediated vasodilation 12) alpha-adrenergic-mediated vasoconstriction unchanged 13) brain autoregulation of perfusion impaired - decreased baroreceptor responsiveness 14) sclerosis & calcification of heart valves 15) increased fibrosis of myocardium 16) increased fibrosis of cardiac conduction system 17) increased serum ANP Comparative biology: - GDF11 reverses LV diastolic dysfunction in mice [6]

Related

cardiovascular disease (CVD) cardiovascular system

General

age-related physiological changes

References

  1. Essentials of Clinical Geriatrics, 4th ed, Kane RL et al (eds) McGraw Hill, NY, 1999
  2. UCLA Intensive Course in Geriatric Medicine & Board Review, Marina Del Ray, CA, Sept 29-Oct 2, 2004
  3. The Merck Manual of Geriatrics, 3rdh ed, Merck & Co, Rahway NJ, 2000
  4. Taffet GE, Physiology of Aging, In: Geriatric Medicine: An Evidence-Based Approach, 4th ed, Cassel CK et al (eds), Springer-Verlag, New York, 2003
  5. Geriatric Review Syllabus, 7th edition Parada JT et al (eds) American Geriatrics Society, 2010 - Geriatric Review Syllabus, 8th edition (GRS8) Durso SC and Sullivan GN (eds) American Geriatrics Society, 2013 - Geriatric Review Syllabus, 10th edition (GRS10) Harper GM, Lyons WL, Potter JF (eds) American Geriatrics Society, 2019
  6. Loffredo FS et al. Growth differentiation factor 11 is a circulating factor that reverses age-related cardiac hypertrophy. Cell 2013 May 9; 153:828 PMID: 23663781
  7. Kitzman DW, Upadhya B, Taffet GE. Effects of aging on cardiovasculare structure and function: In: Ouslander JG, Studenski S et al eds Hazzard's Geriatric Medicine and Gerontology, 7th ed. McGraw Hill;2017:1129-1144