Cardiac Review; CV alterations; Hemodynamics; EKG Flashcards
Definition of systole
Contraction phase of the heart
Definition of diastole
filling phase of the heart
What is the right side AV valve pump and when is it open?
Tricuspid; during atrial systole & ventricle diastole
What is the left side AV valve pump and when is it open?
Mitral; during atrial systole & ventricle diastole
What is the right side SL valve pump and when is it open?
Pulmonic; ventricle systole & atrial diastole
What is the left side SL valve pump and when is it open?
Aortic; ventricle systole & atrial diastole
What does S1 occur with (lubb)?
Ventricular systole (AV valves close)
What does S2 occur with (dubb)?
Ventricular diastole (SL valves close)
S3 heart sound is a sign of?
heart failure; increase venous return (fever, volume overload)
S4 heart sound is a sign of?
forceful atrial contraction; occurs after MI
Normal values for K, Na, Mg, Ca?
3.5-5.5; 135-145, 1.5-2.5; 9-11
Normal Serum lipids: Cholesterol, triglycerides, LDL, HDL?
Less than 200; 40-190; if no CAD or less than 2 risk factors less than 160 & if CAD less than 100; HDL greater than 35
How to calculate MAP?
systolic BP+ 2 X diastole BP/ 3 (good estimate of overall tissue perfusion)
Definition of CO? normal?
volume of blood ejected by each ventricle in 1 min (CO=SV x HR) normal : 4-6 L/min
Definition of SV?
volume of blood ejected by each ventricle per contraction; normal: 60-100 ml
Definition of Ejection fraction?
fraction of blood ejected with each beat; normal 60-70%
What perfect of circulating blood volume is in veins?
70%
When does injury occur to coronary arteries if there is atherosclerosis?
reduced 50-70%
What does PQRST stand for?
Provoke, Quality, Radiation, Severity, Timing
What side of heart is low pressure? High?
right side (venous return); left side (power house pumps to rest of body)
What is the most common cause of clots?
Atrial fibrillation
What three things are essential for perfusion, cardiac status, & hemodynamics?
pressure, flow, resistance
In a cardiac catheter it is important to assess what?
for hemorrhage, monitor vitals, distal pulses, hold metformin could cause lactic acidosis
What are the two types of angina?
stable: occurs w exertion relieved by rest; unstable: partial blockage by thrombus; pain severe not relieve by rest, increased risk for MI
How should you take Nitrates?
take 1 tab every 5 min repeat 5 min if still in pain call 911; get new after 6 months; hold if systolic less than 100
Difference between Angina and MI?
Angina: pain less than15 min w. exertion or stress, doesn’t vary with position, relieved by rest or NTG; MI: pain greater than 15 min, resp. distress more severe, pain not relieved by rest or NTG, skin cold, clammy, N&V, pulse rapid. Irreg
What is non STEMI MI?
non Q wave MI; partial occlusion of CA, ST depression, Elevated Cardiac enzymes
What is STEMI MI?
Q wave MI; total occlusion of CA, ST elevation, Elevated Cardiac enzymes
What does MONA stand for?
Morphine, Oxygen (2L), NTG, Aspirin (2-4 baby chewable)
What five things does Morphine do?
decreases Chest pain, smooth muscle relaxant, decreases anxiety, decreases preload and afterload.
What artery primarily feeds the hearts anterior wall?
Left anterior descending artery
What must a patient be for thrombolytic Mgt of AMI?
symptomatic 20 min unrelieved by nitro and with ST segment elevation
What type of patients can’t get thrombolytics?
stroke, uncontrolled htn, recent surgery/trauma, internal bleeding, aortic dissection, recent preg.
What do nitrates do?
decreases preload & afterload, vasodilates coronary arteries.
What do Beta Blockers (Inderal) do?
decreases HR & contractility.
What do Ace Inhibitors (Vasotec, Captoprol) do?
decrease SVR
What do Phosphodiesterase inhibitors (Amrinone/Inocor) do?
increase contractility & decrease afterload
What does Dopamine do?
stimulates adrenergic receptors; tx of low CO
What does Dobutamine do?
Sympathomimetic. Direct action inotropic agent that enhances myocardial contractility, SV, CO, renal blood flow, UO
Hemodynamics studies relationships among?
HR, blood flow, O2 delivery, tissue perfusion.
Pressure =?
flow x resistance
What is the force exerted on the liquid?
pressure
What is the amount of fluid moved overtime?
flow
What is the measure of the ease with which the fluid flows through the lumen of a vessel?
resistance
What is the pressure of the right atrium and ventricle?
2-6 mm hg; 15-25 mm hg
What is the pressure of the left atrium and ventricle?
8-12 mm hg; 110-130 mm hg systolic/ 8-12 mm hg diastole
What are some factors that affect blood flow?
blood vessel changes, turbulence flow, HR, contractility, renin/angiotension/aldosterone cascade.
What are some factors that affect resistance?
diameter & length of vessel, elasticity of artery, blood viscosity (thickness).
What are some noninvasive ways to assess hemodynamics?
noninvasive BP, assess JVP (measures preload), assess serum lactate levels
BP Size?
width 40% of arm circumference; length bladder cuff covers 80-100% of arm circumference.
JVP elevated could mean?
Fluid overload, HF, R ventricular dysf
What are normal lactate levels? High levels w. hypo perfusion can cause?
0.5-1.6 meq L.; circulatory shock, resuscitation, metabolic acidosis, end organ damage/poor perfusion.
What is determined by the stretch of the ventricles at the end of diastole?
preload
What patients benefit from invasive hemodynamic monitoring?
ineffective tissue perfusion, sepsis, decreased CO, impaired gas exchange, fluid excess/dehydration.
What are examples of invasive modalities?
AP monitoring, RAP/CVP monitoring, PA pressure monitoring
How much pressure needed to push fluid into artery?
300 mm hg
Sites for arterial pressure?
radial, brachial, femoral arteries
What does RAP/CVP catheters measure?
measures R heart filling pressures, fluid status, guides fluid resuscitation
Where do you zero the transducer?
phlebostatic axis: 4th intercostal space LMCL
When do you measure RAP?
end of expiration
What assessments during and after RAP insertion?
pulses, no numbness, neurovascular checks, Breath sounds, HS, Chest x-ray
What do PA caths measure?
RA, RV, PA pressures.
What position does patient need to be in to insert PA catheter?
Trendelenburg, towel roll between shoulder blades.
Why do you inflate catheter balloon?
to float catheter in PA
What function does PA catheter reflect?
Left ventricular function
What is the normal PA pressure?
25 mm hg systolic/ 10 mm hg diastole; mean 15 mm hg
What are the five components of Invasive Hemodynamic monitoring?
invasive catheter, noncompliant pressure tubing, flush system, transducer, bedside monitor
What component of invasive hemodynamics allows for efficient & accurate transfer if intravascular pressure changes to the transducer & monitoring system?
noncompliant pressure tubing & flush system
What component of invasive hemodynamics translates intravascular pressure changes into waveforms and numeric data?
transducer
Phlebostatic axis tells us what?
the exact pressure in heart and artery
How do we know the A-line pressure wave is working correctly?
dicrotic notch will be seen. (aortic valve is closing)
In hemodynamics if preload is elevated what will you see? decreased?
E: increased JVP, peripheral edema, taught skin turgor, crackles
D: decreased skin turgor w. tenting, dry mucus membranes, hypotension, decreased UO
In hemodynamics if afterload is elevated what will you see? decreased?
E: cool, peripheral, weak peripheral pulses, changes in LOC
D: warm extremities, bounding pulses, changing in LOC
What does SvO2 show?
overall O2 use by tissues and organs
What is normal values for SvO2? ScvO2? high means? low means?
60-75%; 65-85%; tissues cannot use O2; O2 demand > delivery
What are the four factors that affect SvO2?
hemoglobin, CO, arterial oxygen saturation, oxygen consumption(VO2)
What are some signs of increased metabolic demand for O2?
fever, hyperthermia, Pain, stress, seizure, shivering
Definition of depolarization?
(precedes systole) electrical firing of impulse: atria= p wave; ventricles: QRS
Definition of repolarization?
Electrical charging(precedes diastole); atria= within QRS; ventricles= t wave
What is the resting potential of myocardial cells?
-90 mv
What happens in phase 0-1 of action potential?
Na rushes in. fast ventricular depolarization takes place
What happens in phase 2 of action potential?
Ca moves thru the slow Ca channel(+20 mv)
What happens in phase 3 of action potential?
rapid repolarization, K leaves the cell.
What happens in phase 4 of action potential?
returns to normal resting state.
What is the lead II placement?
right arm(below clavicle)- neg lead(white); left lower abdomen or left leg- pos. lead(red); left arm- ground lead can be on lower right chest or upper left chest area(black, green, brown)
What is the value of little EKG box? big box?
.04; .20
How many seconds on a EKG strip is used to determine HR?
6 secs
What is P wave generated by?
SA node (pacemaker of the heart): sinus rhythm
Where is PR interval located? normal range value?
beginning of p wave to beginning of QRS: (.12-.20)
Where is QRS complex located? normal range value?
beginning of Q to S: (.06-.12)
What does a wide QRS and no p wave indicate?
ventricular rhythm
QT can be used to determine ?
certain effect of certain drugs on the myocardium(Quinidine)
True or false ST segment should be isoelectric?
TRUE
ST segment depression could indicate? elevation?
myocardial ischemia; myocardial injury or infaract
Any changes with your patient or complaints or pain or discomfort requires a ____ ______ EKG to fully assess the myocardial status?
12 lead
What is atrial kick?
an additional 30% of blood volume into ventricles
Baroreceptors detect changes in? chemoreceptors?
BP;
ph, O2, & CO2 levels
True or False myocardial cells primary function is electrical?
false: mechanical
What is the primary property of myocardial cells?
contractility
True or False Pacemaker cells primary function is electrical
TRUE
What is the primary property of pacemaker cells?
automaticity/conductivity
True or false action potentials primary function is chemical
TRUE
What are some signs of a decreased CO?
diaphoretic, SOB, altered LOC, weakness, fatigue, dizzy, low BP, ischemia, low Pox.
What does it mean by generating electrical impulses without being stimulated?
automaticity
What is the ability of the cardiac muscle cell to respond to an outside stimulus?
excitability/irritability
What is the ability to receive an electrical impulse and conduct to an adjoining cardiac cell?
conductivity
What is the ability of myocardial cell to shorten in response to an impulse?
contractility
What does polarized mean?
when the inside of cell is more neg than outside
True or false a cell can conduct another impulse before repolarization occurs.
FALSE: cannot
True or False a refractory period is a valuable protective mechanism for the heart and is essential for cells to recover.
TRUE
What is absolute refractory period?
cells cannot no matter what be stimulated to conduct an electrical impulse
True or False in a relative refractory period cells can be stimulated if stimulus is strong enough.
TRUE
How many bpm is SA node? AV and bundle of his? purkinje’s network?
60-100; 40-60; 20-40
True or false the slower the heart rate the lower in the heart the impulse started.
TRUE
What do most cardiac EKG strips run out of machine at?
25 mm/sec
P wave represents?
atrial depolarization
PR interval is the time for ?
atrial depolarization to enter the bundle of his
QRS represents?
ventricular depolarization
T wave represents?
ventricular repolarization
How to count heart rate on EKG?
count the R’s in a 6 sec strip and multiply by 10
True or False If not normal QRS doesn’t really count as heart rate, but count anyways.
TRUE
What can drop SvO2 levels?
suctioning, turning patient, weighing, shivering, seizure, pain, increased PEEP, increased intrathorasic levels
True or False having head of bed not elevated and flexed hip can cause increase in intrathorasic pressure.
TRUE
What are the three sites of impulse formation?
Sinus, Atrial, Ventricular
What dysrhythmia is HR less than 60, QRS and PR normal limits, reg. rhythm?
sinus bradycardia
What are some causes of Sinus Bradycardia?
digoxin, sleep, hypoxia, MI, heart disease
What medication is given only if pt is symptomatic with sinus bradycardia?
atropine: 0.5-1mg max of 2. Can stress out heart be cautious
What dysrhythmia is HR greater than 100 in adult, QRS and PR in normal range, rhythm reg.
sinus tachycardia
What are some common causes of sinus tachycardia?
fever, HF, anxiety, shock
: What dysrhythmia is when a site within the atria fires before the next SA node impulse is due to fire, QRS is normal, PR varies.
PAC (Premature atrial contractions): early p wave
What happens in a PAC when the SA node tried to reset itself?
non compensatory pause
What are some causes of PAC’s ?
excessive alcohol use, caffeine, anxiety, MI, HF, digoxin toxicity
What are some significance of PAC’s?
may reflect increasing atrial irritability, not an entire rhythm- it’s a single beat, can lose atrial kick
What is the most common dysrhythmia?
atrial fibrillation
What are some causes of A. fib?
injury to atria (open heart surgery), digoxin toxicity, pericarditis, hyperthyroidism
What are some dangers of A fib?
loss of atrial kick up to 30% decrease in CO, thrombi (clots) along the walls of the atria.
What medications for A fib are good for rate control? Rhythm control?
beta blockers, Digoxin, Ca+ channel blockers; Cardizem
What may be done if pt is A fib with RVR or pt is symptomatic?
synchronized cardioversion (shock) on the R
What is some management for A fib?
anticoagulation- started before attempting to convert or if AF has been present 24-48 hours; hep. Drip initially, lovenox, Coumadin; Amiodarone for persistant A fib
What is the 1st line drug for atrial and ventricular dysrhythmias?
Amiodarone
What dysrhythmia has sawtooth flutter waves with rate of 250-350 bpm, QRS normal, PR can’t measure, no p wave?
Atrial flutter
True or False some common causes of Atrial flutter may be open heart surgery, MI, heart disease
TRUE (also no atrial kick)
Where does Supraventricular Tachycardia (SVT) begin?
above the bundle of his
What are the two types of SVT?
atrial tachycardia: atria fires rapidly; Paroxysmal atrial tachycardia: rapid rate that starts and stops quickly (something goes wrong and changes HR)
What dysrhythmia has reg rhythm, ventricular rate of 150-250 bpm, QRS normal, p wave may merge with t wave of previous beat?
SVT
What are some causes of SVT?
anxiety, alcohol excess, cigs
What medication is given for PAT/SVT?
Adenosine (Adenocard)- 6 mg rapid IV push to slow AV conduction
What dysrhythmia is no p wave, wide, bizarre QRS complex greater than .12, assume no CO, t wave opposite of QRS, beat occurs early, has a full compensatory pause?
Premature Ventricular Contractions (PVC’s)
What is a unifocal PVC?
came from one irritable ventricular site
What is multifocal PVC?
Came from multiple irritable ventricular sites
What is the R and T phenomenon?
elevates ST segment could be MI; can trigger deadly ventricular dysrhythmias
What are some causes of PVC’s?
acid base imbalance (acidosis 7.24), electrolyte imbalance: low K/Mg
What are some signs and symptoms related with PVC’s?
palpitations, irreg. pulse, decreased BP, SOB
True of False routine medications to treat PVC’s are no longer used.
TRUE
What dysrhythmia has 3 or more PVC’s in a row, rate greater than 100, QRS wide greater than .12 & bizarre, sometimes marching p waves.
Ventricular Tachycardia(VT)
What are some causes and possible symptoms of VT?
myocardial ischemia, cardiomyopathy, cardiac cath, dig toxicity.
symptoms: hypotension, loss of LOC, chest pain, SOB, cold, clammy skin.
True of False in VT you should call 911 its an emergency, why?
TRUE: hemodynamically unstable- no pulse, need CPR and defibrillation.
What do you treat polymorphic VT or Torsades de pointes with?
Mg
What does ventricular fibrillation look like?
no p waves, no QRS, no pulse..
