-
Outer layer of heart
Pericardium
-
Middle layer of heart
myocardium
-
inner layer of heart
- endocardium
- forms the 4 chamber separating valves
-
-
left AV valve
mitral bicuspid
-
aortic valve seperates
- L ventricle and aorta
- semilunar
-
pulmonary valve seperates
right ventricle and pulmonary artery
-
ECG 'P'
atrial depolarization and contraction
-
ECG 'Q,R,S'
Ventricular depolarization and contraction
-
ECG 'T'
- Ventricular re-polarization and relaxation
- recovery phase
-
SA node
- pacemaker of heart
- WNL 60-70 BPM
-
-
Arrhytmias on ECG show as variations and may indicate acute problems such as
- infarction
- systemic electrolyte imbalances
-
SA nodal problems or total heart block may require this device
pacemaker
-
this can be implanted for conversion of ventricular fibrillation
Defibrillator
-
What are barorecptors and where
-
Beta blockers
- block SNS stimulation
- block (stop) any increase in rate/force of contraction
-
HR increases with
- Increase temp
- Increase environmental temp/high humidity
- Exercise
- Smoking
- Stress
- SNS stimulation
- dehydration
- caffinee
-
Cardiac Cycle
Atria relax-> Pressure in atria open AV valves-> blood enters ventricles-> conduction stimulates atrial muscle to expel any remaining blood to ventricles-> atria relaxes-> ventricles begin to contract-> av valve closes-> semilunar valves open-> blood enters pulmonary artery and aorta-> atria begin to fill as ventricles relax
-
Whats occurring during heart sounds
Closure of valves
-
What causes murmur
- defective valves that leak or don't open fully
- turbulence in flow makes sound
-
cardiac output
volume of blood from ventricle in one min. CO=HRxSV
-
Exercise __ return of blood to heart
increase
-
-
CO=HRxSV definition
- cardiac output= (heart rate) x (stroke volume)
- HR= number of ventricle contractions each minute
- SV= amount of blood ejected from each ventricle with each contraction
-
Factors affecting CO
- HR- SNS, epinephrine
- SV- Venous return (preload), blood volume, SNS, peripheral resistance (after load)
-
-
What is pulse pressure
Diastole-Systole
-
BP variables
- CO and peripheral resistance
- Venous return (preload)
- HR
- force of contraction of ventricles
- peripheral return/resistance (afterload)
- elasticity of arteries
-
Peripheral resistance factors
- constric/dilation of arterioles
- -increase sns= vasoconstriction
- -decrease sns= vasodilation
- blood vessel obstruction
-
What happens when BP changes sensed by baroreceptors
- info sent to medulla
- blood flow adjusted to maintain normal BP ie rising from supine
- SNS, epinephrine- Increase HR and force of contraction
-
Auscultation diagnostic test
valve abnormalities
-
exercise stress test
- bike, step, treadmill
- assess CV function and arrhythmias
- used in fitness clubs/cardiac rehab program
-
-
arterial blood gas test
- check on O2 level
- acid base balance
-
CAD includes
- Angina pectoris
- MI
- May lead to HF, arrhytmia, or suddent death
- Not enough O2 for needs of heart
-
CAD arteriosclerosis
- changes of small arteries/arterioles (loss of elasticity and walls thick and hard)
- lumen narrows
- leads to ischemia/necrosis of kidneys, brain, and/or heart
-
CAD atherosclerosis
- plaques- lipids, cells, fibrin, and debris
- associated with thrombi
- primarily in large arteries
- often starts from an injury to artery when very young
-
CAD etio
- unchangeable factors
- age >40
- Premenopause protected by higher HDL levels
- Genetics/lifestyle
- changeable factors
- obesity/high fat diet
- cig smoking
- sedentary lifestyle
- DM (diabetes mellitus)
- HTN
- Oral contraceptives
-
CAD tx
- decrease cholestrol levels esp LDL
- decrease sodium
- control HTN, diabetes
- stop smoking
- anti-coagulant therapy: coumadin or ASA
- Surgery for atheroma
- -flatten thru cath using balloon
- -LASER
- -CABG reroute blood flow around using veins
-
Angina Pectoris Patho
O2 deficit due to obstruction or spasm in artery or patient working/exercising harder than usual
-
Angina pectoris etiology
insufficient blood supply due to athero, arterio, or artery spasm
-
angina pectoris tx
- rest
- nitroglycerin
- O2
- with known angina hx 2nd dose of nitroglycerin if still in pain after 5 min; if after 10 min assume heart attack
-
MI patho
- coronary artery totally obstructed
- ischemia/cell death
- usually from atherosclerosis
- quick attention decreases area of necrosis
-
MI SNS
- pain in chest, left arm, and neck
- pain described as steady, severe, crushing with no relief
- sometimes misinterpreted as gastric pain
- pallor/sweating
- hypotension, pulse weak/rapid
- low grade fever
-
MI tx
- Rest
- O2 therapy
- analgesics
- anticoagulants
- cardiac rehab programs
- -individualized exercise plan, schedule for return to normal function
-
MI prognosis
30-40% mortality in 1st year
-
Cardiac arrest
- cessation of all heart activity
- ECG flat line
- all cardiac function ceased
- no impulse conduction
- heart and brain deprived of O2
-
CHF patho
- heart unable to pump enough blood
- may be problem in heart ie valve or from HTN or a lung disease
- body may attempt to compensate resulting in less blood to organs
-
CHF when heart can no longer maintain itself these occur
- CO/SV decrease
- "backup" congestion in circulation occurs
- blood inflow>output
-
CHF etio
- infarcts that effect pumping capacity of heart
- valve defects
- congenital heart defects
- CAD leading cause
-
CHF SNS
- fatigue, weakness, dyspnea
- SOB, exercise intolerance
- cold intolerance
-
L CHF
- HTN or infarction of left ventricle
- orthopnea/dyspnea
- left ventricle circulation backup into pulmonary artery (drowning lungs)
- cough
- paroxysmal nocturnal dyspnea
-
R CHF
- cannot keep up with output
- blood backs up into LEs
- dependent edema
- hepatomegaly/spleenomegaly
- ascitis (fluid accumulates in abdominal cavity)
- Pressure on vena cava
- -distended neck veins, HA, facial flushing and visual distrubances
-
rheumatic heart disease patho
- acute inflam 5-15 y/o
- new streptococcus strains occur
- occurs after a few weeks of an untreated infection
- antibodies form usually but then react abnormally
- may affect larg ejoint in the child especially legs, may migrate
- also may effect skin, other joints with subcutaneous nodules
- may affect brain resulting in jerky movement of face, arms/legs
-
rheumatic heart disease SNS
- systemic inflam: low grade fever and malaise
- anorexia
- fatigue
- tachycardia, heart murmurs, acute HF, arrthymias
-
rheumatic heart disease TX
- penicillin
- anti-inflam (ASA/cortico steroids)
|
|