Cardiovascular Disease Flashcards
acute coronary syndrome (ACS)
range of conditions associated with symptomatic CAD that result in myocardial ischemia or infarction
- imbalance of myocardial O2 supply and demand
non modifiable risk factors for acute coronary syndrome
age, male gender, DM type 1, genetic predisposition
modifiable risk factors for acute coronary syndrome
hyperlipidemia, hypertryglyceridemia, DM type 2, metabolic syndrome, HTN, obesity, physical inactivity, smoking, diet
most common cause of acute coronary syndrome
- coronary atherosclerosis
- other causes of decreased coronary blood flow
coronary atherosclerosis
thickening / narrowing of blood vessels
what can decrease coronary blood flow
- vasospasm
- myocardial trauma
- structural disease / valve disease
- congenital anomalies
- decreased O2 supply
- conditions in which increase demand for O2
triggers of inflammatory response in endothelial cells
- dyslipidema
- diabetes
- auto-immune mechanisms
- increase blood viscosity
- vessel wall sheer stress
- increase fibrinogen
- viral infections
ischemic pain
typically described as diffuse rather than localized, described as knife like or burning
- not relieved by antacids, nor affected by respiration, or NSAIDs
- n+v are symptoms more common in inferior MI affecting the LV
- dyspnea may be present of LVF is present
- variations according to gender and diabetes
acute coronary syndrome classification
(1) may have ECG changes of ischemia but no damage
(2) NSTEMI
(3) STEMI
NSTEMI
non ST elevation MI
ischemic ECG changes and elevated cardiac markers
STEMI
ST segment elevation MI on ECG and elevated cardiac markers
stable classification
pain with exertion and relieved by rest
unstable classification
pre-infarction or crescendo, symptoms more frequent and last longer, pain may occur at rest
silent ischemia
pt has ECG changes but shows / experiences no symptoms
on an ECG for ischemia the hyperactive phase shows a
tall T wave
on an ECG for ischemia the early acute phase shows
tall T wave and elevated ST segment
on an ECG for ischemia the later acute phase shows
elevated ST segment and inverted T wave
on an ECG for ischemia the fully evolved phase shows
elevated ST segment and inverted T wave and Q wave
Infarction depends on
length of time and absorbent blood flow, extent of collateral flow and the degree in which vasoactive changes occur as a result of loss of blood flow
______ min without blood flow results in permanent damage
25-30 min
_____ min causes irreversible injury
40-60 min
explain “time is muscle”
- door to drug within 30 min
- door to balloon inflation 90 min
- 12 lead ECG within 10 min
- targeted history and physical done asap
treatment for STEMI
- antiplatelet, anti-ischemic, or anti-coagulant therapy
- thrombolytics
- PCI or CABG
- long term management
treatment for NSTEMI
- antiplatelet, anti-ischemic, or anti-coagulant therapy
- PCI or CABG
- long term management
what is CABG
coronary artery bypass graft
serum troponin
cTn1 - cardiac specific - sensitive indicator of early MI
- done on admission - 6 and 9 hrs, repeat in 12-25hrs
- superior sensitivity and specificity
Cardiac markers
CK-MBs is a cardio specific isoenzyme indicating myocardial necrosis
when does the CK begin to rise
increase begins 4-12 hrs from onset of damage
what is a rise in CK marker dependent on
dependent on cardiac damage, therefore MI with minimal damage may go undetected
a EKG should be done within ____ mins
10 mins
leads I, II, III show
positive QRS deflection
aVR is
negative QRS deflection
aVL is
biphasic
aVF is
positive QRS deflection
V1 lead
QRS is a negative deflection
QRS progresses through until V__
V6
ischemic area is composed of ________, where _____________ and this shows __________
viable cells where repolarization is impaired but eventually becomes normal; shows T wave inversion
injury surrounds the ________ zone; cells do not fully _______; this shows ___________
infarcted zone; repolarize; this shows ST elevation
infarction refers to the area of _______________ and ____________; this causes lack of ____________ and is shown in the ___________-
cellular death and muscle necrosis; repolarization; Q waves
transmural infarcts
involve 50% or more of the total thickness of the ventricular wall
what characterizes transmural infarcts
Q waves and ST changes
non transmural infarctions may involve ______________ or ______________ portions of _________
sub-endocardial; pericardial; ventricle
percutaneous coronary intervention (PCI)
catheter with small ballon inserted via an artery into the occluded coronary artery. The balloon is inflated to re-open the coronary artery to resume vessel patency and blood flow.
what is the treatment of choice for STEMI
percutaneous coronary intervention (PCI)
thrombolytic therapy
pharmacological agents - tPA
- must be given within the first 3hrs post MI
- adjunct therapies include heparin, enoxaparin
when giving thrombolytics what preparations and assessments are needed
- continuos cardiac monitoring
- med administration
- IV hydration
- pt and family education
- NPO prior to
- ALLERGIES - shellfish
contraindications of thrombolytic therapy
- active bleeding
- aortic aneurysm
- recent brain injury or trauma
- AV malformation
- intracranial neoplasm
- previous hemorrhagic stroke
what is a stent
provides structural support to the artery
when are stents placed
at time of angioplasty
nursing management of pt undergoing PCI
- frequent vital signs
- assess site bleeding, clotting, and limb circulation
- maintain straight leg and limit mobility
- fluids IV and oral
- anti-platelet drugs (plavix)
- anticoagulant (heparin)
- pt and family anxiety
complications of PCI
- hypotension
- severe anaphylaxis
- bleeding post-thromolytic therapy
- superficial bleeding at puncture sites is most common
- reperfusion arrhythmias
- rupture of vessel
- emboli from angioplasty
- stent placement
routine for pt with chest pain
- assess and vital signs
- IV
- MONA
what is MONA
Morphine
Oxygen
Nitroglycerin
Aspirin
stroke volume
amount of blood ejected from the left ventricle with each heartbeat
cardiac output
amount of blood the heart pumps each minute
equation for cardiac output (CO)
heart rate (HR) x stroke volume (SV) = CO
how much blood does the heart pump per minute
4-8L/min
preload
stretching of myocardial cells in a chamber during diastole, prior to onset of contraction
- “priming process” of pump
how is preload measured
as the end-diastolic volume or end-diastolic pressure
preload is equal to _______ return plus the residual volume left in _______ chamber after the last ________
venous; cardiac; contraction
increased _________ and increased _______ _______ means the heart works harder
preload; stroke volume
afterload
amount of resistance to the ejection of blood from the ventricle - it is the amount of pressure that the heart must pump against
afterload = _________
pressure
pressure = _______ x _______
flow x resistance
major factors that influence afterload
- vascular resistance
- diameter and distendability of aorta and pulmonary artery
- blood pressure
ejection fraction (EF)
% of blood expelled from the left ventricle with every contraction
myocardial contractility
the force/strength of ventricular contraction
contractility can be affected by
MI, angina, HF, infectious heart disease, valvular disorders
Heart failure
an abnormal condition involving impaired cardiac pumping
in heart failure angiotensin I is converted to ______________ = ____________ and increased _____
angiotensin II; vasoconstriction; BP
increased bp = _________ afterload
increased
aldosterone release causes ________
sodium and water retention
sodium and water retention from aldosterone release causes _______________ and ______________
increased preload and worsens failure
risk factors for heart failure
HTN, CAD, valvular heart disease, peripheral vascular disease, lifestyle choices, infectious diseases, medication effects, metabolic disorders
mitral stenosis
narrowing of the mitral valve orifice
affects of mitral stenosis
- reduces blood volume to L ventricle
- reduces cardiac output
- rise in pressure in L atrium
- causes L atrial hypertrophy and pulmonary congestion
- increased pressure in pulmonary vessels
what does increased pressure in pulmonary vessels cause
hypertrophy in R ventricle and R atrium
medication used for cardiovascular diseases
- diuretics
- morphine
- calcium channel blockers
- beta blockers
- ACE inhibitors
- digoxin
- nitroglycerin
what are the basic cell working groups
(1) myocardial working cells
(2) specialized pacemaker cells
myocardial working cells
responsible for generating the physical contraction of heart cells
- physical contraction of myocardial tissue actually generates blood flow
where are myocardial working cells
muscular layer of arterial walls and thicker muscular layer of ventricle walls
specialized pacemaker cells
do not have the ability to contract
- responsible for controlling rate and rhythm by coordinating regular depolarization
- primary function is generalization and conduction of electrical impulses
where are specialized pacemaker cells found
in electrical conduction system of the heart
primary cardiac cell characteristics
(1) contractility
(2) automaticity
(3) excitability
(4) conductivity
contractility
mechanical function - also referred to as rhythmicity, ability of cardiac cells to shorten and cause cardiac muscle contraction in response to electrical stimulus
automaticity
electrical function - ability of cardiac pacemaker cells to spontaneously generate own electrical impulses without stimulation
excitability
electrical function - ability of cardiac cells to respond to electrical stimulus; also referred to as irritability
conductivity
electrical function - ability of cardiac cells to receive an electrical stimulus and then to transmit the stimulus to other cardiac cells, they function collectively as a unit
cardiac depolarization
when impulse develops and spreads throughout the myocardium, changes occur in the heart muscle fibers
difference between cardiac depolarization and repolarization
depolarization - Na rushes into the cell, changing interior charge to + after cell is stimulated
repolarization - Na returns to outside the cell and potassium returns to inside of the cell
three major cations that affect cardiac function
(1) potassium
(2) sodium
(3) calcium
how does potassium affect cardiac function
performs major function in cardiac depolarization and repolarization
how does sodium affect cardiac function
performs vital part in depolarization of myocardium
how does calcium affect cardiac function
important function in depolarization and myocardial contraction
___ node depolarizes
SA node
electrical activity goes rapidly to the ____ node via ________ _________
AV node via internodal pathways
________ spreads more slowly across atria and conduction slow through ____ node.
depolarization; AV node
depolarization moves rapidly through ventricular conducting system to the ______ of the ______
apex of the heart
depolarization wave spreads ________ from the apex
upwards
sinoatrial node is the
primary pacemaker of the heart
SA node is located in
the upper posterior portion of the R atrial wall of the heart
SA node firing rate
60 to 100 bpm
what occurs after impulse leaves SA node
depolarization and myocardial contraction
internodal pathways receive
electrical impulse as it exits SA node
internodal pathways transmit impulse from ____ node to ____ node
SA node to AV node
atrioventricular node is located
on the floor of the R atrium above tricuspid valve
AV node delays electrical activity ___ seconds
0.5 secs
AV node allows for more
complete filling of the ventricles
the AV node is the only pathway of ________ elctrical impulse to the __________
atrial electrical impulse to the ventricles
AV junction
where SA node joins bundle of HIS
AV junction is the
secondary pacemaker
if the SA node fails or slows below normal the ___ _________ tissues initiate electrical activity
AV junctional
Bundle branches
conduct electrical activity from bundle of HIS to Purkinje’s network
- divide into 2 branches; L and R branches
a 12 lead EKG views the heart in _____ distinct planes
2
two planes an EKG views the heart in
frontal - what limb leads look at
horizontal - what vector leads look at
normal ejection fraction (EF)
50 - 70%
