hemodynamics Flashcards
compliance of the heart
The “stretch ability” of the heart
elasticity
The ability of the myocardial wall to return to its original shape of “snapback”
contractability
The force of the contractions generated by the myocardium
preload
The maximum degree of stretch of the myocardial fibers, just prior to contraction
What is preload influenced by
Fluid volume/body position
ischemia
Hypertrophy
Pericardial restriction
afterload
The amount of resistance the heart has to overcome to pump the blood
wall stress
The amount of strength and stretch required for the heart to pump
Mean arterial pressure MAP and normal values
The optimum pressure for assuring continuous oxygen and nutrient supply to the body
90-95
Low MAP indicates
less tissue perfusion
What is arterial BP determined by
cardiac output and resistance to blood flow
stroke volume
The amount of blood ejected by the ventricles with each contraction
Starlings Law
The more the normal myocardial fibers are stretched, the greater the force which they snap back
cardiac output and equation
The volume of blood ejected by left ventricle/min
CO = SVR x HR
What 2 things do the sympathetic nervous system release? And what do they do
They release epinephrine and norepinephrine
Increases HR
Vasoconstriction
Fight or flight
What does the parasympathetic system do
The vagus nerve may decrease HR
Rest and digest
what do baroreceptors do
Sense decreased pressure in the aortic arch and respond by increasing force and rate of contraction
Baro=pressure
what do chemoreceptors do
Sense changes in O2, CO2, and pH and respond to changing heart and respiratory rates
Total peripheral resistance and three things its determined by
The amount of obstruction to blood flow produced by the system
Valvular flexibility of stiffness, vascular resistance, volume of blood
How do baroreceptors respond to increased/decreased stretch of aorta
Increased stretch: vasodilation
Decreased stretch: vasoconstriction
Localized myogenic response
Local blood vessels dilate or constrict in response to increases or decreases in blood flow
2 catecholamines
Epinephrine and norepinephrine
What does ADH do for blood volume
Increases it (antidiuretic, so you’re releasing less fluid)
Primary HTN
idiopathic, common
Secondary HTN
Caused by another disease, can be reversible if disease is controlled
Normal BP, pre HTN, Stage 1, Stage 2
Normal: <120-80
Pre-HTN: 120-139/80-89
Stage I: 140-159/90-99
Stage II: >160/100
Why does alcohol change BP and how does it change it
It increases BP
It increases renin which increases RAAS activity
Na+, K+, Ca+, Mg+, and glucose in relation to HTN
High Na+
Low K+, Ca+, Mg
Glucose intolerance
What race and age group is at high risk of HTN
African Americans
Males <50, females >50
Insulin in relation to HTN
Arteries damaged by insulin resistance
RAAS in relation to HTN
Overactivity lead to HTN
Late symptoms of HTN
Frontal headache in the morning, dizziness, nose bleeds, confusion
Isolated systolic HTN 3 criteria
SBP >140
Diastolic BP <90
pt >65
What can malignant HTN lead to
Papilledema, CVA, encephalopathy, CHF, uremia
orthostatic HTN and diagnosis
Drop in SBP of 20 mmHg or diastolic 10 mmHg within 3 min from sitting to standing
Tilt table test
Varicose veins (what are they, etiology by, S&S, treatment)
Dilated or tortuous veins that typically leads to venous insufficiency
Etiology: Long periods of standing, increase intraabdominal pressure (pregnancy)
S&S: Distended veins, aching in lower extremities, edema
Treatment: Support hose, sclerotherapy, surgery
Venous insufficiency
Chronic venous disease of lower extremity
Caused by incompetent valves
Edema, venous stasis dermatitis
Risk factors of venous thrombosis
Venous stasis (bedrest)
Hypercoagulable states (BC, leiden control V, cancer, pregnancy, childbirth)
Vessel wall injury (orthopedic surgery, venous catheters, massive trauma or infections
What can venous thrombosis lead to
SOB, palpitations, anxiety, afib, low O2 sat
S&S of venous thrombosis
Pain, swelling, fever, general malaise, elevated D-dimer >500
Homans sign
Dorsiflexion produces pain
Treatment for venous thrombosis
Anticoagulants (heparin, lovenox)
exogenous lipoproteins
ingested
endogenous lipoprotiens
liver
LDL normal levels
Optimal is less than 100, less than 70 for high risk
HDL normal levels
40-60
Triglycerides normal range and when elevated
<150
DM, increased alcohol, sugar
Treatment of hyperlipidemia
diet, exercise, statins
what does atherosclerosis lead to
CAD
Stroke
PAD
what is fibrous atheroma developed from
Fatty streaks, clinical atherosclerosis, accumulation of intra and extracellular lipids, smooth muscle proliferation, scar tissue, and calcification
complicated atherosclerosis
Fibrous plaque breaks open, producing hemorrhage, ulceration, and scar tissue deposits
