Nursing 2005: Cardiovascular Disorder (Part 3) Manifestations of the Heart Idease and Shock Flashcards
SA (sinoatrial) node
- def
- loc
- rate
pacemaker
- loc: upper right atrium
- atrial myocardium causing contraction of atrium
- rate: 60-80 beats per min
AV (atrialcentricular) node
- def
- loc
- rate
Loc: upper right atrium
- slows impulse before it reaches ventricles so that it can push blood to ventricles
- if SA if fails, AV takes over
- rate: 40-60 beats per min
Bundle of HIS = purjunkie fibers (ventricles)
- def
- rate
- ventricles can take over as pacemaker but slower
Rate : 15-40 beats/min
EKG
- P
- QRS
- T
- electrical activity of the heart
- P = atrial depolarization
- atria contracts
- QRS = ventricular depolarization
- ventricles contract
- T= ventricular depolarization
- ventricles recocer
Dysrhthmias
- abnormal heart rate and rhythm
– disturbance in conduction system
What is the etiology of dysrhythmias?
- abnormal rhythmicity of SA node
- SA is still acting as peacemaking but wrong rhythm - shift of pacemaker function
- block of conduction system
- abnormal conduction pathway
- spontaneous impulses
- SA works normal but other part of heart takes over = ectopic pacemaker and starts an impulse = disturbs rhythm
What is the cause of dysrhythmias?
- MI
- Electrolyte imbalance = potassium
- abnormal Ph
- meds
- stress
- alcohol
Types of dysrhythmias: SA node
- Sinus Bradycardia
brady =slow
- rhythm normal
- EKG normal, but rate slow
- SA node heart rate <60
- normal for athletes and when sleeping
What is the etiology of sinus bradycardia?
- hypothermia
- inc vagal stimulation
- meds
What are the problems with sinus bradycardia?
- Greater chance for ectopic sites to fire
- dec cardiac output
What are the S/S of sinus bradycardia?
- related to dec in CO
- weakness, dizziness
What are types of treatment for sinus bradycardia?
- med to inc HR
- pacemaker
- Sinus Tachycardia
tachy = fast
- rhythm normal
- EKG normal, but rate fast
- SA node fires at >100
What is the etiology of sinus tachycardia?
- physiological stress
- exercise, pain, fever
- anxiety, anemia, low blood sugar, drugs
What is the significance/problems with sinus tachycardia?
- inc work of heart and demand of O2 -> inc risk of angina, MI
- ok for a short period but constantly it leads to angina or mi
What are types of treatment for sinus tachycardia?
- meds to dec HR and dec O2 demand
Types of Dysrhythmias: Atria
- Premature Atrial Contraction (PAC)
- def
- EKG reading
- contraction originating from ectopic focus in atria,
- not SA node
- transmit to vent., early beat.
- EKG = P with QRS but not spaced regularly
What is the etiology of PAC?
- can occur in healthy people
- stress, caffeine, alcohol, valvular disease
What type of meds are given for PAC?
digoxin
- Atrial flutter
- def
- rate
- EKG reading
- filing time
- rate 160-350
- delay through AV node
- EKG – many P waves but QRS once in a while but regular
- respond to every 2nd, 3rd, 4th but regular
Causes dec filling time:
- dec CO -> lead to CHF
- not enough filling of ven
What is the etiology of atrial flutter?
- CAD
- HTN
- mitral valve disorder
What type of treatment is used for atrial flutter?
- meds to slow ventricular responnse
- Cardioversion
- voltage shock to the R wave
- jolts heart back to normal rhythm
- Atrial Fibrillation
- def
- rate
- EKG reading
- rate 350-600.
- Atrial quivers, no contraction
- EKG – can’t see P waves, QRS irregular
- atria quivers
What is the etiology of atrial fibrillation?
- happens with people who have underlying heart disease
HTN, RHD, CAD, CHF
Wbat are the problems/dangers with atrial fibrillation?
- dec CO precipitate CHF
- from no contraction of atria
- pooling of blood = emboli
- causes blood clots
What type of treatment is used to treat atrial fibrillation?
- same as a-flutter plus anticoagulants
Types of Dysrhythmias: Ventricles
- Premature Ventricular Contractions
- def
- EKG reading
- contraction originating in ectopic focus in ventricle.
- premature ventricle contraction
- EKG: premature QRS, wide and distorted
What is the etiology for Premature Ventricular Contractions?
-associated with stimulants = caffeine, low potassium, stress, acid-bace imbalance, lack of sleep, meds
What are the problems of Premature Ventricular Contractions?
- dec co = heart failure
- angina
- defib
- life threatening if 3 PVCs in a row = ventricular tachycardia
- ventricles take over as pacemaker
What types of treatment are used for Premature Ventricular Contractions?
- Lidocaine
- correct the underlying cause
- Ventricular Tachycardia
- rate
- EGK reading
- 3 or more PVC in row
- Rate 110-250
- ventricles take over
- no p waves, distorted QRS waves
What is the etiology of Ventricular tachycardia?
- MI
- CAD coronary artery disease
- electrolyte imbalance
- mitral valve problems
What are the life threatening problems that ventricular tachycardia can cause?
– CO dec, very little
- loss of consciousness
- possible progression to V-fib
- dec coronary perfusion
What type of treatment is used for ventricular tachycardia?
- Lidocaine to slow ventricular response
- cardioversion
- voltage shock on R wave
- Precodial thump
- hit pt on chest
- Ventricular Fibrillation
- def
- EKG reading
- vent quivers, no contraction
- Multiple ectopic sites
- EKG – HR not measurable
What is the etiology of ventricular fibrillation?
- MI
- cardiomyopathy
- electrical shock
- inc potassium
- hypoxia
What are the dangers/problems from ventricular fibrillation?
- no CO
- no pulse
What type of treatment is used for ventricular fibrillation
- CPR
- defibrillation
Heart Failure
- heart unable to pump enough blood to meet metabolic needs
- Caused by any interference with normal mechanisms regulating CO.
- systolic failure patho
Common cause of heart failure : MI and HTN
- caused by impaired contractile function
- inc afterload
- valve problems
- Unable to generate adequate CO
impaired emptying.
- Unable to generate adequate CO
Leads to:
a. dec L ventricular ejection fraction
b. inc L ventricular end-diastolic volume
- more blood = bigger heart chambers = dialate
c. inc L ventricular end-diastolic pressure
d. inc pulmonary pressure
- Diastolic failure
- problems with relaxation and filling
- Diastolic failure=High filling pressures and venous congestion
- Pulmonary congestion present with normal CO.
Compensatory Mechanism
- overtime = heart failure d/t dec CO
1. Sympathetic stimulation
- inc HR, contractility to inc CO
- inc epinephrine = inc HR
- over time over worked heart
- Dilation
- muscle fibers stretch = inc CO
- d/t blood pooling
- overtime over stretching
- Renal Response
renin released= BP inc
- Hypertrophy
- inc mass = inc CO
- muscles become thicker for CO
- overtime thickness in muscles = inc O2
Types of Heart Failure
- Left- sided Heart Failure (congestive heart failure)
- systolic/diastolic failure
- most common and happens first
- one side may be effect but over time both sides will fail because its compensating
- causes blood to back up into pulm circulation.
- leaks in LV line
- Inc pulm pressure causes fluid to leak from pulmonary capillary beds to alveoli –> pulmonary congestion.
What are the main problems of LHF?
Poor CO
Backed up blood = pulm congestion
What are the clinical manifestations of Left HF?
- weakness, fatigue
- pale cool skin
- vasoconstriction - chest pain
- inc workload of heart - pulmonary edema
- backed up blood and leaks to LV = in lungs = sob, diff breathing - confusion
- no o2 in brain - metabolic acidosis
- lack of o2
- Rely on anaerobic - nocturia
- inc urine output at night
- Right Sided Heart Failure
- caused by left sided heart failure, MI, lung disease = pneumonia, tumor
- causes backflow of blood in venous system = venous congestion
- dec cardiac output
What are the clinical maneifestations of Right HF
- venous congestion
- liver engorgement
- ascites = edema in abdomen
- anasarca = mass body edema - jugular vein distention
- fatigue
- Peripheral edema
What types of treatment are used for Right HF?
positive anotropic agents
a. digoxin
- dec hr
b. diuretics
- dec fluid
- dec preload on heart
c. vasodilators
- dilate blood vessels
- oxygen
- not enough gas exchange d/t edema - low sodium diet
- risk of fluid retention
- on fluid restrictions 1800 cc fluids/day
Shock
- failure of CV system to perfuse tissues adequately
- inadequate blood flow to organs = lack of O2 and nutrients to cells
- Impairment of O2 use
no O2, cells shift to aneorobic metabolism
- less efficient, less energy -> can’t operate Na-K pump.
- Na stays in cell -> water in
- dec circ volume -> activation of clotting cascade
- release of lysosomal enzymes and inflammatory response.
- aneorobic metabolism causes inc acid -> impair cell function.
- Impairment of glucose use
- shift to lipolysis, gluconeogenesis, glycogenolysis
- Protein breakdown -> ammonia, urea -> toxic to cells -> organ failure
Types of Shock:
- Cardiogenic Shock
- Heart can’t pump blood efficiently
- dec CO
- d/t MI = massive heart attack
What is the patho of cardiogenic shock?
- occurs after MI. Dec in compliance and contractility d/t infarction
- > dec CO, dec BP
- Low arterial pressure -> dec CA perfusion -> inc ischemia
What are the clinical manifestations of cardiogenic shock?
a. impaired thought process = dec bp
b edema, pulmonary and peripheral
c. hypotension- dec UO
d. dec renal perfusion – dec Urine output
What type of treatment is used for cardiogenic shock?
a. restore CA blood flow – angioplasty
b. thrombolytics
c. intraaortic balloon pump
d. inotropic meds
- inc contractility of heart (+)
- Hypovolemic Shock
- loss of intravascular volume
- failure of CV system because cant profuse tissues
- lack of blood flow, o2, nutrients to cell
- hemmorhage, burn victims, extreme dehydration = vomit, diarrhea
What is the patho for hypovolemic shock?
- dec vascular volume -> dec venous return, dec CO.
- Compensatory mechanism
- HR, SVR inc, interstitial fluid moves into vascular space.
- Stored RBC and plasma released.
- Kidneys secrete renin.
- Compensatory mechanisms fail = dec CO and inadequate perfusion.
What are the clinical manifestations of hypovolemic shock?
a. drop in BP
b. inc HR, thready pulse
c. poor skin turgor
d. thirst
e. dec UO
f. dec in mental status
- d/t lack of blood flow
What types of treatment are used for hypovolemic shock?
- volume replacement
- blood and blood products for hemorrhage
Neurogenic Shock
- massive vasodilation
- from parasympathetic NS over stimulation or sympathetic under stimulation.
What is the patho for neurogenic shock
- vasodilation = dec SVR
- pooling f blood
- dec HR and CO
- inadequate perfusion
What are the clinical manifestations of neurogenic shock?
- low BP
- dec HR
- fainting
What type of treatment is used for neurogenic shock?
- fluid replacement
- meds to inc BP
Anaphylactic Shock
- allergic reaction
- stim immune and inflam respnse
What is the patho of anaphylactic shock?
- Immune response causes vasodilation and inc vascular permeability
- > peripheral pooling of blood and edema -> dec perfusion.
- respiratory problems possible
What are the clinical manifestations of anaphylactic shock?
a. dec BP
b. weak pulse
c. dec mental status
d. anxiety
e. difficulty breathing
f. skin rash
What types of treatment are used for anaphylactic shock?
a. epinephrine
b. antihistamines
c. steroids
- dec inflam
Septic Shock
- bactieremia
- sepsis
infection
– bacteremia = bacteria in blood
– sepsis = infection in blood
– septic shock
SIRS – systemic inflammatory response syndrome.
What is the patho of septic shock?
- gram (-) bacteria.
- Endotoxins trigger inflammatory responses
- bind to monocytes, macrophages
– stimulate release of mediators.
- Mediators cause vasodilation, inc capillary permeability
- dec in myocardial contractility -> organ failure.
What are the clinical manifestations of septic shock?
a. dec BP
b. fever
c. flushed skin
d. chills
e. confusion
f. edema
What type of treatment is used for septic shock?
a. antibiotic therapy
b. fluids
