patho1 ch 16

not done

Blood flows from systemic to

pulmonary to systemic circulation

Systemic Arterial Pressure

* momentum for blood flow
* if in xs damage tissues and vessels
* pressure dif between L & R sides of heart that makes gradient for flow

Arterial Systemic Blood Pressure:

Determinants

radius of artery

vessel compliance (stretch)

SVR (afterload)

resistance

cardiac output (CO)

blood exiting ventricle per minute

* CO= SV x HR

blood pressure

systolic pressure/ diastolic pressure

* directly proportional to vol
* controlled by hormones

Systolic pressure:

exerted when blood is ejected from ventricles (high)

* ventricular contraction
* 1st sound

Diastolic pressure:

sustained pressure when ventricles relax (lower)

* ventricular diastole
* when sound stops

normal BP (mmHg)

sys

elevated BP

sys 120-129

dia

HTN stage 1

sys 130-139

dia 80-89

HTN stage 2

sys __>__ 140

dia __>__ 90

mechanisms of BP regulation

short term

long term

short term BP reg mech is a

rapid adjust in response to

* switch position
* exercise
* emot change
* physio change

short term reg mech:

mediated by

sympathetic branch of the ANS

short term reg mech:

regulated by ____ center in the medulla

vasomotor

short term reg mech:

Vasomotor center directly activated by

* various stimuli
* indirectly via pressure-sensitive baroreceptors ((MAP) variations)

short term reg:

stimulation of SNS causes release of nt’s

noradrenaline

adrenaline

short term reg:

SNS release of noradrenaline & adrenaline activates

**α**1 receptors

**β**1 receptors

short term reg:

activation of a1 receptor

^vasoconstrict

^SVR

^ contract

short term reg:

activation of B1 receptor

of heart will ^hr

short term reg:

increasing the hr by

SNS & PSNS

short term reg:

increasing contractility of heart by

SNS

long term reg mech:

weeks-months

* neural, hormonal, renal interactions
* connected w/body fluid vol

long term reg:

^extracellular fluid vol causes

^CO & SVR → ^BP

long term reg:

elevated BP causes kidneys to

excrete (lose) excess sodium & water (fluid)

long term reg:

^serum Na causes ^osmolality →

^H2O intake as ADH is secreted makes kidney retain water

long term reg:

more blood =

more vol = more bp

long term reg:

RAAS

* juxtaglomerular cells stim by low arterial p → release renin → activate angiotensin → angio 1
* angio 1 contacts ACE → angio 2
* angio 2 **vasoconstrict** & get aldosterone released by adrenal cortex

long term reg:

RAAS- aldosterone

hormone

* causes Na & water reabsorption
* more blood vol= more bp

normal fluctuations in systemic bp

* body’s internal clock (__suprachiasmatic nuclei)__
* rise before waking
* highest in mid day
* lowest at night
* neural, hormonal, envi factors
* lifestyle

most common primary diagnosis in the US

hypertension

\-leads to other diseases

\-can damage any organ

hypertension is the most common risk factor for ___ worldwide

CVD

hypertension:

Increases morbidity and mortality associated with

heart disease,

kidney disease,

peripheral vascular disease

stroke

hypertension:

frequently damaged areas

Kidneys
Heart
Brain
Retina

hypertension:

Predisposing factors

* Incidence increases w/age
* Men affected more
* More in women after middle age
* Genetic factors
* Na intake, xs alcohol intake, obesity, smoking, recurrent stress

Hypertensive crisis:

Sys >180 and/or dia >120

* patients need change meds
* or immediate hospitalization if signs of organ damage

Primary (Essential) hypertension –

idiopathic (Majority of hypertensive cases)

* Blood pressure > 130/90 mm Hg
* Systolic is risk for CVD
* Silent killer

Primary hypertension other effects

rare to under 10 y/o

incidence in kids in escalating

* systolic BP major risk of CVD

Primary hypertension:

subtypes

isolated sys

isolated dia

combined sys and di

Primary hypertension:

non modifiable risk factor

oFamily history

oAge

oEthnicity/Genetics

Primary hypertension:

modifiable risk factor

* Dietary
* Sedentary
* Obesity/weight gain
* Metabolic syndrome (Elevated circulating insulin and lipid levels)
* Elevated blood glucose levels/diabetes
* Elevated total cholesterol
* Alcohol and smoking

Primary hypertension:

silent killer

damage to organs occur before diagnosis sometimes

Primary hypertension:

end-organ damage

* renal failure
* stroke
* heart disease

Primary hypertension:

treatment - lifestyle modifications

Weight loss
Exercise
DASH diet (Dietry Approaches to Stop Hypertension)
Alcohol moderation
Decreased sodium intake

Primary hypertension:

treatment - drug therapy decreases

* hr
* SVR
* SV

Secondary hypertension common cause

kidney (renal) disease

Secondary hypertension

etiology

* from renal/endo disease
* from pheochromocytoma (benign tumor of adrenal medulla)
* Underlying problem must be treated to reduce

Secondary hypertension is ___ to treat than primary

easier

* not idiopathic can find cause

Secondary hypertension: is the most common form of hypertension in

infants & pre-k kids

Secondary hypertension: most common cause for child cases

renal disease

coarctation of aorta (congenital narrow)

Secondary hypertension: another cause for kids

sleep apnea- less O → hr^ → ^bp eventually

Secondary or primary hypertension is more common

primary

Secondary hypertension in adults can be related to

renal disease

tumors

pregnancy

obesity

obtrusive sleep apnea

hyperaldosteronism

Secondary hypertension: from renal disease

arterial stenosis

glomerulonephritis

renal failure

Secondary hypertension from tumor

pheochromocytoma

kidney, ^noradrenaline & adrenaline released

Secondary hypertension related to pregnancy

chronic hypertension

pre-eclampsia

gestational hypertension

Secondary hypertension related to

Hyperaldosteronism:

most common cause

Hypertensive emergency:

sudden increase in either/both systolic or diastolic blood pressure w/evidence of end-organ damage

* 25% of all ER visits

Hypertensive emergency:

treatment

Rapid but controlled bp reduction by parenteral antihypertensive agents under close monitoring

(typically in ICU setting)

Hypertensive urgency:

similar blood pressure elevation (to emergency) without evidence of end-organ damage

Hypertensive urgency:

treatment

oral meds to reduce bp under control over 24-48 hrs

orthostatic (postural) hypotension

* extreme response to supine→ upright position
* activation of short-term control mech is slow or inadequate

hypotension: causes a decrease in

sys __>__ 20 or __>__10 (w/in 3 mins)

when moving upright

hypotension: results in

dizziness

blurred vision

confusion

possible syncope

hypotension:

is associated with

CVD

hypotension:

is a risk factor for

stroke

cog impair

death

hypotension:

can be result of

Problem vasomotor/baroreceptor response

Adverse effect of drug therapy

Arterial stiffness

Volume depletion

Secondary disease process

Vasovagal reaction

Cardiac dysrhythmias