Myocyte ultrastructure unchanged; ß in myocyte #; Ý in myocyte volume; Ý in patchy areas of fibrosis; suggestion of myocyte "dropout" (Ý in programmed cell death??)
Physiology
Systolic function preserved
in absence of other cardiac disease
Diastolic function
ß with age in absence of disease
Impaired myocardial relaxation; Age-related
Ý in vascular resistance in absence of HTN; Proposed relationship to arterial sclerosis with age; "non-hypertensive cardiac hypertrophy"
Response to exercise
ß in maximal HR (MHR = 225 - age); ß in maximal oxygen uptake; Effect of age on systolic function ("cant train an old heart" Þ HR decreases with age, Ý in stroke vol. with exercise in aging in absence of cardiac disease); in absence of other cardiac disease, cardiac output is preserved however HR is blunted so must have exercise-induced SV increases
Aging-specific issues in cardiac disease
systolic hypertension
prevalence of systolic HTN Ý with age; isolated systolic HTN Ý vascular mortality!; treatment of isolated systolic HTN ß CV mortality
syncope
sudden loss of consciousness
Differential Diagnosis = cardiac, "other"
; Mortality risk of cardiac cause; However, fall-driven morbidity and mortality from either cause i.e., hip fracture
Cardiac causes
Arrhythmias
Conduction system disease (third degree A-V block, first degree A-V block, bifasicular block on EKG); Ventricular tachycardia; Atrial fibrillation with rapid ventricular response
Mechanical-limitation of cardiac output
Aortic stenosis (Harsh, late-peaking systolic murmur); Hypertrophic cardiomyopathy (Second peak in incidence in elderly age group, Dynamic outflow obstruction, Marked diastolic dysfunction, Accentuation of systolic murmur with Valsalva)
Syncope in elders
history, physical exam, EKG; specialized testing directed by H and P
Holter monitor
(continuously records), Event monitor (only records when you activate it when you feel "funny", you wear it like a watch) for arrhythmias
Echocardiogram
"Other" causes
multifactorial decrease in cerebral perfusion
age-related impairment of baroreceptor reflexes (enhanced norepinephrine release; down-regulation of alpha-receptors; may be component of Parkinsonian complex)
vasodilator medications
heart-rate blunting medications
congestive heart failure
impaired relaxation ("diastolic dysfunction") 40% of elders have normal systolic function; superimposed disease upon baseline impairment (HTN, Ischemia)
age-specific death rate for CHF continues to increase with age
readmission rates for elderly patients
for heart failure patients (>70 years of age), multiple hospitalizations within 6 months are common
readmission rates within 90 days in elderly patients (57% for recurrent heart failure)
heart failure patients with preserved systolic function
20% to 50% of patients with symptomatic heart failure have preserved LV systolic function
pt profile
: more elderly, female, HTN, comorbidities (morbidity is high in this group; mortality also substantial)
treatment goals: reduce LVH,
Ý LV relaxation, careful reduction in filling pressure
Interaction of Aging Myocardium with Disease States
clinical introduction
heart disease is the most frequent cause of death > 65 years of age
age is an independent adverse prognostic factor for morbidity and mortality following myocardial infarction