EKG Quiz #5: MI and Infarction (added anatomy to Emily Kemme's quizlet)
how would you describe a pathological Q wave
>25% of R wave >0.04 sec in continuous leads
T/F if someone had a past MI, the Q wave will go away
F, Q waves never go away due to scar tissue
what leads indicate a lateral wall MI?
I, aVL, V5, V6
the Q wave is normal in what leads
I, aVL, V5, V6 (look at lateral side of the heart)
what leads indicate an inferior wall MI?
II, III, aVF
branches into left anterior descending & left circumflex
Left coronary artery
the ST segment can be compared to the ____ segment to evaluate depression or elevation
PR
first downward deflection from baseline
Q wave
first part of the QRS complex
Q wave
this is the first downward deflection from the baseline, not always present
Q wave
normal in leads I, aVl, V5 and V6
Q waves
flat line that follows the QRS complex and connects it to the T wave
ST segment
return to the isoelectric line on EKG
ST segment
the key to diagnosing STEMI and non-STEMI on EKG
ST segment
this is a flat line that follows the QRS complex and connects it to the T wave
ST segment
depicts repolarization of the ventricles
T wave
no more than one box high (5mm) and 10 mm long
T wave
slightly asymmetrical and oriented in same direction as preceding QRS complex
T wave
this wave is slightly asymmetrical and oriented in the same direction as the preceding QRS complex
T wave
posterior infarctions can be diagnosed by looking for RECIPROCAL changes in what leads?
V1, V2
what leads indicate a septal wall MI?
V1, V2
what leads indicate an anterior wall MI?
V3, V4
what lead does not localize any ECG change because its reading is always upside down?
aVR
coronary (arteries/veins) deliver blood to the myocardial cells while coronary (arteries/veins) return deoxygenated blood to the R atrium via coronary sinus
arteries, veins
what is the number one cause of myocardial ischemia
atherosclerosis
how does atherosclerosis cause MI?
collagen is deposited which causes a plaque and causes thrombus formation leads to acute decrease in coronary blood flow.
____ ____ deliver blood to myocardial cells
coronary arteries
____ ____ return deoxygenated blood to RA via coronary sinuses
coronary veins
ST segment ELEAVATION =
earliest sign that myocardial infarction has occurred
in pericarditis the elevated ST segment is....
flat or concave in ALL LEADS
on EKG you see a Q wave that is getting bigger and occur in different places or they are big, deep, broad, does this relate to (ischemia, injury or infarction)?
infarction
on EKG you see an elevated ST segment, does this relate to (ischemia, injury or infarction)?
injury
pathologic Q waves indicate the presence of _________ myocardial damage or myocardial infarction
irreversible
ST segment DEPRESSION =
ischemia
on EKG you see a T wave that is *inverted* or tall and peaked or there is a depressed ST, does this relate to (ischemia, injury or infarction)?
ischemia
list infarction, ischemia, and injury in the order in which they happen
ischemia, injury, infarction
these occur with interruption of coronary artery blood flow and is a progressive process
ischemia, injury, infarction
supplies anterior surface, part of the lateral surface of L ventricle & anterior 2/3 of septum
left anterior descending
supplies LA, anterolateral, posterolateral and posterior wall of LV
left circumflex
nurse MONA (acronym)
morphine, oxygen, nitrates and aspirin
this is death of the myocardial cells
myocardial infarction
the results if ischemia progresses unresolved or untreated
myocardial injury
this results from decreased oxygen and nutrient delivery to the myocardium and can be reversed if supply of oxygen is restored
myocardial ischemia
should be used in caution or avoided in inferior wall MI
nitrates
since the arteries are smooth muscle, techniques like ____ can help reprofuse if there is narrowing
nitroglycerin
small (less than 25% the amplitude of the R wave) and narrow (< 0.04 seconds)
nonpathologic Q wave
what is a main condition ST segment elevation is seen in?
pericarditis
depression in ST in other leads that are not capturing the MI are experiencing a....?
reciprocal change
85-90% also have branches into the AV node
right coronary artery
originates from the right side of the aorta
right coronary artery
supplies RA and RV, inferior & posterior LV & posterior 1/3 of the interventricular septum
right coronary artery
supplies SA node in 50-60% of population
right coronary artery
can increase coronary blood flow through ____ to meet increased myocardial oxygen demands
vasodilation
