24. & 25. MI/ECGs Flashcards
What does an EKG do
records electrical activity (depol) of heart from viewpoint of each ind lead
what plane do the limb leads show depol
frontal (coronal)
what leads show depol in the horizontal plane
precordial leads
what is the normal direction of depol
upper right to lower left (RA to LV)
a positive deflecion on the QRS is ____
toward the lead
a negative deflection is ____ from the lead
away
QRS lead 1 (+) & avF (-) mean–
left axis deviation
what problems can lead to left axis deviations
ascities ( move herat & diaphragm up)
large belly
LV hypertrophy
QRS lead 1 = (-) & avF = (+)
right axis deviation
lung dieases show what kind of deviation
right axis deviation
what are symptoms associated with MIs
nausea, vomiting, diaphoresis, dyspnea
chest discomfort: heavy, pressure crushing
retrosternal, L, across chest, radiate into neck, jaw, L arm/shoulder, epigastrium or btn shoulder blades
what could be present with partial occlusion
unstable angina
NSTEMI
if coronary flow is occluded, pt presents w/
STEMI
what is the most likely cause of MI
atherosclerosis
If there is ischemia - you’ll see –
T wave changes - inverted, tall peak or depressed
-deficient blood supply & impaired repol
myocardial injury is seen by
ST segment shifts
deficient blood supply & inability to fully polarize
infarctions are seen w/ —
changes in Q waves (wide)
dead tissue, lack depol
when is tropinin I & T detectable during a MI
1-4 hours after onset
-pears at 10-24 hr
what can cause false positive cTnT
renal failure
how much ST elevation shows STEMI
men - >= 2 mm at J poin in V2-3
women- >= 1.5 mm
what leads are supplies by the L circumflex A
avL
lead 1
V5-6
= lateral wall of heart
which leads are supplied by left anterior descending A
V1 - V4
= anterior wall of heart
which leads are supplied by the right coronary A
lead 2, 3
aVF
= inferior wall of heart
which leads are supplied by the posterior descending A
V1-3
= posterior wall of heart
how would a lesion of left CCA seen on an EKG
circumflex A - lead 1, aVL, V5-6
left ant descending A - V1 - V4
sinus tachycardia is presented w/
HR > 100
what can cause sinus tachycardia
drugs, hyperthyroid,
fever, prego,
anemia, CHF,
hypovalemia
OR normal
what can cause sinus bradycardia
HR < 60
= vagal response, sleep apnea, meds, MI, increased ICP, hypothyroid
what can cause premature atrial beats
& what do they look like
stress, alc, tobacco, coffee, COPD & CAD
see a P wave and QRS different from all others
what causes premature ventricular contraction
normal, stress,
hypoxia,
drugs
heart failure, AMI, ischemic heart disease
cardiomyopathy
electrolyte disorder
what does a premature ventricular contraction look like on an EKG
wide QRS
HR 150-250
multiple wide QRS complexes next to each other =
ventricular tachycardia (VTACH)
what are causes of VTACH
CAD, heart failure, hypertropic cardiomyopathy,
congenital heart disease, electrolyte abnormalities
narrow QRS
fast HR (160-180)
p waves masked by QRS
Supraventricular tachycardia (SVT)
what are causes of SVT
-what population is most affected
thyroid disease, caffiene, meds with stimulants, stress
kids & young women
what does irregularly irregular mean
atrial fibrillation
irregular RE intervals
what are causes of Afib
Hypertensive heart disease
vavulvar heart disease
CHF, CAD, DM, CKD
obesity, metabolic syndrome
a PR interval longer than 0.2 sec =
primary AV block
