1. Orthostatic Hypotension in the Elderly Dan Michael Sodano, MD, FACC, RPVI BMG Cardiology

2. Epidemiology Occurs in upwards of 30% of the elderly
Typically not found in the healthy elderly and should not be expected in the healthy
Associated with falls, syncope, and hospitalization
Seen in 68% of those discharged from acute geriatric ward
Significant percentage of those with asymptomatic orthostatic hypotension – approaches 33% of individuals

3. Normal Response to Standing
There may be a slight reduction of systolic blood pressure
Can be upwards of 20% reduction in cardiac output
Diastolic blood pressure may be unchanged to slightly increased
There may be 5-20 beats per minute increase in heart rate, which can be blunted in the elderly

4. Control of Blood Pressure
Baroreceptor reflex
Found in the carotid sinus and aortic arch
Sensitive to changes in pressure
Decrease in pressure leads to less stretch which then sends signal to medulla oblongata leading to stimulation of sympathetic nervous system which then activates vasoconstriction
Increase in pressure leads to more stretch which then sends signal to medulla oblongata leading to stimulation of parasympathetic nervous system (by inhibiting sympathetic activation) which then activates vasodilation of arterioles and decreases cardiac stimulation and HR which serves to lower blood pressure by lowering cardiac output

6. Control of Blood Pressure
Chemoreceptor reflex
Found in the medulla oblongata
Primarily involved in regulation of respiration and ventilation, but in extreme circumstances, can elevate BP
Decrease in PO2, increase in CO2, increase in pH
Leads to stimulation of vasomotor center which serves to:
- increase HR
- increase contractility
- increase vasoconstriction
- All serves to increase blood flow to heart and lungs

8. Regulation of Falling BP
Baroreceptors are inhibited
Decreased impulses to the brain
Decreased parasympathetic activity and increased sympathetic activity
Heart: Increased HR and contractility
Vessels: Increased vasoconstriction
Adrenal gland: Increased release of norepinephrine/epinephrine
All serve to increase contractility and HR
End result is increase in mean arterial pressure

9. Definition of Orthostatic Hypotension
Reduction of systolic blood pressure of 20 mmHg and/or reduction of diastolic blood pressure of 10 mmHg within 3 minutes of standing
Change in heart rate or presence of symptoms are not included in the definition
Head up tilt at 60° can be used in place of standing

10. Risk Factors of Orthostatic Hypotension in the Elderly
Cardiac diseases such as severe AS, cardiomyopathy, severe restrictive cardiomyopathy
CNS diseases (very important)
Chronic hypertension
Venous insufficiency
Antihypertensives
Diabetes mellitus
Alcoholism
Amyloidosis
Dementia

11. Presentation of Orthostatic Hypotension
Important to note that many patients exhibit atypical symptoms such as:
Backache
Headache
Neck pain
Shortness of breath
Chest pain
Seizures
Fatigue
Severely reduced blood flow to heart and brain  angina, TIA
Typical symptoms predominant and include:
Postural dizziness
Postural syncope/presyncope

12. Neurogenic Causes of Orthostatic Hypotension
Neurogenic causes – autonomic failure due to idiopathic central and peripheral neurodegenerative causes
Primary causes of autonomic failure
Parkinson’s disease
Lewy body dementia
Pure autonomic failure
Multiple system atrophy (Shy-Drager syndrome)
Secondary causes of autonomic failure
Diabetes mellitus
Primary amyloidosis

13. Non-neurogenic Causes of Orthostatic Hypotension
Age-related – related to comorbidities, medications, hospitalizations, illness
Cardiac pump failure
Extensive myocardial infarction
Constrictive pericarditis
Aortic stenosis
Significant tachyarrhythmias or bradyarrhythmias
Reduced intravascular volume
Metabolic
Adrenocortical insufficiency
Hypoaldosteronism
Pheochromocytoma
Venous pooling
- Prolonged recumbency, standing, hot baths/showers, hot environment

14. Medications Associated with Orthostatic Hypotension
Diuretics
Vasodilators – hydralazine, nitrates, dihydropyridine CCBs
Alpha blockers
Beta blockers
CNS sedatives
Tricyclic antidepressants
Phenothiazines
Alcohol

15. Head-up Tilt-Table Testing

16. Pathogenesis Impairment of the baroreceptor reflex
Changes in baroreceptor reflex arc: heart rate response, vascular compliance, vasopressin release, renin-angiotensin and renal concentrating response
Depressed myocardial contractility and vascular responsiveness
Impaired autonomic reflex arc (afferent, central, or efferent)

17. Bedside Evaluation of Orthostatic Hypotension
History
Physical examination
Look for signs of volume depletion
Parkinsonian features
Neuro exam
Foot exam looking for evidence of diabetic peripheral neuropathy
Good cardiac examination looking for murmurs, JVD, heart size
Orthostatic vital signs (after 1, 3, and 5 minutes)

19. Ancillary Methods to Assist with Evaluation
ECG: looking for signs of MI, bradyarrhythmias, tachyarrhythmias
Echocardiogram: evaluating for cardiomyopathy, aortic stenosis
Head-up Tilt Table Testing
Laboratory analysis
BUN/Cr
Na and K
Glucose
Cortisol and Aldosterone when indicated
Catecholamines when indicated

20. Non-pharmacologic Treatment
Acceptance
Maintaining good hydration (at least 2 L/day)
Increasing salt intake where appropriate
Avoidance of deconditioning
Gradual rise from seated positions, after meals, or defecation/urination
Small and frequent meals
Avoidance of prolonged standing or hot/humid environments
Physical counter-maneuvers (leg crossing, muscle tensing, squatting) whilst standing
Elastic stockings

21. Pharmacologic Treatments
Midodrine - α agonist
Droxidopa – norepinephrine precursor
Pyridostigmine – acetylcholinesterase inhibitor (for neurogenic orthostatic hypotension only)
Fludrocortisone – mineralocorticoid leading to volume expansion
Desmopressin – vasopressin analogue and also expands volume