CHP 18: CARDIAC Flashcards
group of disorders of the heart and blood vessels
cardiovascular disease
what the left ventricle produce when it contracts
apical impulse
the apical impulse is also called the ____
point of maximal impulse
the right side of the heart is a ___-pressure system aka ___ circulation
low, pulmonary
the left side of the heart is a ___-pressure system aka ____ circulation
high, systemic
what is the largest diameter but shortest coronary artery
left main
what does the LMCA divide into
left anterior descending artery and the circumflex artery
what parts of the heart does the LAD supply
left ventricle, portion of interventricular septum
what parts of the heart does the Cx artery supply
left atrium
what parts of the heart does the branches of the RCA supply
right atrium and ventricle, SA node, AV bundle
4 properties of cardiac cells
automaticity, excitability, conductivity, contractility
what does stimulation of the parasympathetic nerve fibers do in the heart
slows rate of SA node, slows conduction of AV node, weakens atrial and ventricular contraction
3 major ACS’s
unstable angina, NSTEMI, STEMI
chest discomfort that occurs when the heart muscle does not receive enough oxygen is called what
angina pectoris
what is inflammation of the pericardial sac
pericarditis
where will patient experience pain with pericarditis
similar to MI pain
pain that beings in the center of the chest and radiates to the back can be indicative of what 2 things
aortic dissection or enlargement of aortic aneurysm
anginal symptoms usually last less than how long
20 mins
AMI symptoms can last how long
20 mins to several hours
dyspnea that develops suddenly suggests what
pulmonary embolism, pneumothorax, acute pulmonary edema
dyspnea that occurs on exertion or at rest suggests what
COPD or left ventricular failure
sudden onset of difficulty of breathing in which the patient suddenly awakens from sleep is what? what is it usually associated with?
paroxysmal nocturnal dyspnea, associated with left ventricular failure
pulmonary edema often produces what type of sputum
pink-tinged
what condition may cause chest pain form inflammation of cartilage and bones in chest well
costochondritis
crackles or wheezes in lung sounds can suggest what
left ventricular failure with pulmonary edema
strong pulsations in the epigastric area may be a sign of what
abdominal aortic aneurysm
bilateral pitting edema may be a sign of what
right ventricular failure
weak, thready pulse or pallor suggests what
reduction in cardiac output
how to test for pulse deficit
stethoscope of apical pulse and hand over peripheral pulse to compare
what is pulsus paradoxus
systolic BP falls more than 10mmHg with inspiration
what cardiac conditions can cause pulsus paradoxus
AMI, cardiogenic shock, cardiac tamponade, constrictive pericarditis
what is pulsus alternans and what is it indicative of
beat-to-beat difference in strength of pulse
severe ventricular failure
normal pulse pressure range
30-40mmHg
stage 2 hypertension criteria
systolic BP 140 or higher and diastolic BP of 90 or higher
what does pulse pressure reflect
stroke volume and elasticity of arterial walls
widened pulse pressure is indicative of what
later stages of shock
narrowed pulse pressure is indicative of what
tachycardia and cardiac tamponade
what conditions may cause BP to vary from right to left side
stroke or aortic aneurysm
when do S1 sounds occur and what causes the sound
beginning of ventricular systole
tricuspid and mitral valves close (AV valves)
when do S2 sounds occur and what causes the sound
end of ventricular systole
pulmonary and aortic valves close (SL valves)
what is a gallop rhythm
S3 in ventricular diastole
what is S4
rare heart sound before S1 caused by turbulent filling of stiff ventricle
what is an abnormal whooshing sound
murmur
phase 0 of cardiac action potential
sodium rapidly moves into cell, calcium slowly moves in, cell depolarizes
phase 1 of cardiac action potential
potassium leaving cell, cell begins to repolarize
QRS complex
phase 2 of cardiac action potential
plateau phase, sodium and calcium slowly enter, potassium leaves
ST segment
phase 3 of cardiac action potential
repolarization finishes, calcium and potassium leaves cell
T wave
phase 4 of cardiac action potential
resting phase
what phases of the cardiac cycle is the absolute refractory period
0-3
what phases of the cardiac cycle is the relative refractory period
middle of 3 to beginning of phase 4
what is the interatrial pathway connecting SA and AV nodes
Bachmann bundle
what is the middle internodal tract
Wenckeback
what is the last internodal pathway
Thorel tract
how long does the AV node delay the SA node’s impulse
0.12secs
what is the only electrical connection between the atria and the ventricles and what does it consist of
AV junction - AV node and nonbranching portion of bundle of His
what causes a delta wave
the bundle of Kent depolarizes to bypass AV and trigger early depolarization of ventricles
what nerve is responsible for decreasing heart rate
vagus nerve or cranial nerve X
what is straining or forced exhalation against a closed glottis
Valsalva maneuver
what drug is a parasympathetic blocker that opposes ACh
atropine
where are baroreceptors located and what do they do
carotid arteries and aortic arch
detect BP changes
sodium’s role in cardiac function
initiates depolarization
potassium’s role in cardiac function
initiates repolarization
calcium’s role in cardiac function
depolarization of pacemaker cells and myocardial contractility
magnesium’s role in cardiac function
stabilizes cell membrane, works with potassium and against calcium
limb leads:
precordial leads:
augmented leads:
I, II, III
V1-V6
aVR, aVL, aVF
an imaginary line joining the positive and negative poles of a lead
lead axis
left leg electrode is ___ charged
right arm electrode is ____ charged
left arm electrode is ___ charged
always positive
always negative
positive to RA, negative to LL
one small ECG paper box is __ seconds
one large box is ___ seconds
0.04
0.2
what does the P wave represent and what are its parameters
atrial depolarization
less than 0.11 seconds
what is the PRI interval and what are its parameters
beginning of P wave to beginning of QRS, AV node delaying transmission
0.12-0.2 seconds
what does the QRS represent and what are its parameters
ventricular depolarization
less than 0.11 secs
parameters for Q wave
first negative deflection in QRS
less than 0.04 seconds, less than 1/3 of QRS complex’s height
what is the R wave
first upward deflection of QRS complex
what is the S wave
any downward deflection after R wave
hat is a second upward deflection in QRS complex called
R-prime wave
R wave is depolarization of __ ventricle
S wave is depolarization of __ ventricle
right
left
what is the J point
QRS complex ends and ST segment begins
end of depolarization and beginning of repolarization
what is the ST segment
begins at J point and ends at T wave
period between ventricular depolarization of repolarization
elevated ST segment indicates ___,
depressed ST segment indicates ___
myocardial injury
myocardial ischemia
what does the T wave represent
ventricular repolarization
peaked T waves are indicative of
hyperkalemia
a tall U wave can be indicative of what
hypokalemia
QT interval parameters
beginning of QRS to end of T wave
0.4-0.44secs
what is the R-R interval
period between QRS complexes, interval between two ventricular depolarizations
5 step method for ECG interpretation
- identify waves
- measure PRI
- measure QRS duration
- determine rhythm regularity
- measure heart rate
two classes of dysrhythmias
disturbances of automaticity or disturbances of conduction
an impulse or rhythm originating from a site other than SA node
ectopic
how to calculate the upper limit of sinus tachycardia
220bpm - patient’s age
what is sick sinus syndrome
variety of rhythms from poorly functioning SA node
alternating patterns of extreme brady and tachycardia
most common type of SVT
AV nodal reentrant tachycardia
what is “occurring in spasms”
paroxysmal
what are cannon A waves and what physical sign can be found
dissociation between atria and ventricles
depression of jugular veins forming an “a” during wave
early depolarization of ventricular tissue through an accessory pathway between atria and ventricles
preexcitation
most common preexcitation disorder
Wolff-Parkinson-White syndrome
what disorder causes preexcitation of ventricular tissue and is characterized by short PRI and normal QRS
Lown-Ganong-Levine syndrome
what disorder causes preexcitation and is characterized by short PRI and widened QRS delta wave
WPW
what rhythm increases risk for emboli and strokes
afib
rhythm in which atria quiver instead of contract
afib
rhythm in which atrial impulse fire too rapid for ventricles
aflutter
rhythm in which P wave shape varies
wandering atrial pacemaker
rhythm in which multiple ectopic sites within atria depolarize at rapid rates
multifocal atrial tachycardia
