Primary and Secondary Hypertension Flashcards
Proportion of population 20-79 with HTN
20%
Proportion people over 60 with HTN
~50%
Hypertension and Atherosclerosis
- HTN accelerates atherosclerosis
- atherosclerosis puts pt at risk for cardiovascular disease
Relationships between hypertension and coronary artery disease
Linear
HTN Co-morbities that increase risk of CVD
- Type II DM
- obesity
- hypercholeterolemia
Diagnosis of HTN
- moving target, important to check guidelines
- want to expedite diagnosis and get treatment started in high-risk pt’s
- three visits, week apart each with three readings of systolic >160 or diastolic >100
- five visits 140-160 and 90-100
- ambulatory monitoring - mean awake BP >135 or diastolic >85
- pt’s with diabetes/chronic renal disease, HTN = >130/80
- HTN >180/100 diagnosed on first office visit
Two pathways that work to control BP
- neural
- humoral
Neural Pathway
-sympathetic nervous system
Humoral Pathway
-Renin-Angiotensin-Aldosterone System
RAAS System
- decrease in perfusion pressure at macula densa in distal tubule causes release of renin from juxtaglomerular apparatus
- renin converts circulating angiotensinogen to angiotensin I
- angiotensin converting enzyme in pulmonary capillary endothelium converts angiotensin I to angiotensin II
Effects of Angiotensin II
- release of aldosterone from adrenal cortex
- vasoconstriction
- hypothalamus - induces release of AVP and induces thirst
Effect of AVP
-increased reabsorption of water, more water into extracellular space
Effect of Aldosterone
-increased sodium reabsorption, more sodium in EC space, more water pulled out of urine
Primary HTN
- also known as essential HTN
- HTN with no obvious cause to explain it
- most common cause of HTN
- underlying mechanism unknown
- genetic factors play a role
- linked with obesity, diabetes mellitus, dyslipidemia
- could be due to enhanced response to catecholamines
- people who migrate take on HTN prevalence of the country migrated to
Secondary HTN
- HTN due to an underlying obvious cause
- 1-10% of HTN pt’s have secondary HTN