advanced ekg Flashcards
hyperkalemia can turn into what waves
sine
QRS complex:
QRS widening
fusion of QRS-T
loss of the ST segment
hyperkalemia
ST depression and flattening of the T wave
Negative T waves
A U-wave may be visible
hypokalemia
P-waves are widened and of low amplitude due to slowing of conduction
hyperkalemia
Severe: extremely wide QRS, low R wave, disappearance of p waves, tall peaking T waves.
hypercalcemia
hypercalcemia causes
tumor lysis in cancer
stimulation from PTH periop
(get baseline/ postop labs)
hypocalcemia
Narrowing of the QRS complex
Reduced PR interval
T wave flattening and inversion
Prolongation of the QT-interval
Prominent U-wave
Prolonged ST and ST-depression
most commonly associated with hypothermia, may also occur in hypercalcemia.
osborn J wave
changes will appear as a reciprocal, negative deflection in aVR and V1.
osborn J wave
causes of delta wave
WPW and abherrnat pathway
a slurred upstroke in the QRS complex. It relates to pre-excitation of the ventricles, and therefore often causes an associated shortening of the PR interval
delta wave
cautious with what two drugs with delta wave
adenosine and CCBs
Lead I is therefore an ___ tracing.
Lead 1 good for looking at?
Lead I is therefore an upright tracing.
Lead 1 for atria
lead III is better for looking at?
ventricles
Lead II is also the recommended lead of choice for
Lead II is also the recommended lead of choice for electrical cardioversion.
12 lead views from 10 electrodes why?
augmented leads
Note that in lead III the baseline wanders up and down. This is due to
due to the positive electrode being located on the diaphragm.
how to improve lead placement
Supine position is recommended
Clip or shave chest hair if necessary
Wipe diaphoretic skin with a towel
Consider using benzene, alcohol, betadine
Shoulders do NOT count
Shoulders do NOT count as limbs!
4th intercostal space, right of sternum
v1
4th intercostal space, left of the sternum
v2
between V4 and V2
v3
5th intercostal space, the mid-clavicular line.
v4
5th intercostal space, anterior axillary line
v5
5th intercostal space, the mid-axillary line
v6
first negative deflection after P wave in any lead
Q wave
first positive deflection after P wave in any lead
R wave
negative deflection below the baseline after an R or Q wave
s wave
where the qrs complex ends and ST segment begins
J point
An RSR prime complex is a classic pattern for
a right bundle branch block in lead MCL1
The R prime wave represents
the second time the complex goes above the isoelectric line.
The J point is important for two reasons
One, it is the point of reference for determining bundle branch blocks; and
two, it is the point of reference for measuring the ST segment elevation.
lead I upright
lead II down
lead III down
pathological left axis
lead I down
lead II down
lead III down
extreme right axis
ventricular in origin
prolly Vtach
lead I down
lead II indeterminate
lead III upright
right axis
Point out that a left bundle branch block ______ a right bundle branch block because _______
Point out that a left bundle branch block is worse than a right bundle branch block because it involves two out of three fascicles.
Also mention that you do not look for ST segment elevation in the presence _____ due to ______
the presence of a left bundle branch block due to the late repolarization of the left ventricle distorting the ST segment.
drugs such as Lidocaine and Procainamide are contraindicated.
bifasicular blocks
RCA supply
Inferior Wall (LV)
Posterior Wall (LV)
Right Ventricle
SA and AV Node
Posterior fascicle of LBB
Left anterior descending LAD supply
“Widow Maker”
Anterior Wall of LV
Septal Wall
Bundle of His and BB
Circumflex supply
Circumflex
Lateral Wall of LV
SA and AV nodes
Posterior Wall of LV
Chest Pain on Exertion =
Chest Pain at Rest =
Chest pain unrelieved by nitroglycerin =
Chest Pain on Exertion = 70 - 85% occlusion
Chest Pain at Rest = 90% occlusion
Chest pain unrelieved by nitroglycerin = 100% occlusion
heparin and ASA dosage for acute MI
5000 units
325mg
A normal 12 lead doesnt rule out?
An MI
Symmetrical inverted T waves in 2 or more related leads
Ischemia
Can cause__ transiently with induction
ischemia
ST segment elevation of more than 1mm in 2 or more related leads
injury pattern
In the absence of ST elevation, then ST depression generally means
ischemia or subendocardial injury
inferior RCA infarct what leads
II, III, F
recip: I, aVL
septal LAD infarct what leads
V1, V2
anterior LAD infarct what leads
V3, V4
recip: II, III, aVF
lateral CIRC infarct what leads
V5, V6, I, aVL
recip: II, III, aVF
posterior RCA infarct what leads?
V8, V9
Right vent RCA infarct what leads
V4R
Pathologic Q waves
> 40 ms wide or 1/3 depth of r wave height
infarction
Point out that 50% of the time an inferior has___, and 30% of the time the _______
Point out that 50% of the time an inferior has posterior involvement, and 30% of the time the right ventricle is involved
Clinical signs of a right ventricular infarction include
include hypotension, JVD, and clear lung sounds
Patients may have bradycardia and hypotension
Could also have 1st degree or Mobitz 1 blocks
what infarct?
inferior MI
Most common seen. Can be fatal
Nausea is common, antiemetics
Use nitrates with caution, may need fluids
what infarct?
inferior MI
most lethal (highest mortality)
can suddenly develop, CHB, VF or VT
anterior wall MI
this MI can extend to septum or lateral
nitrates are great, fluids are spared
anterior wall MI
if seen with hemiblocks or BBB, place quick combo pads on the patient and prepare for the worst
what MI?
anterior MI
Patient feels better when they lean forward
will not have reciprocal ST depression
pericarditis
This condition can have ST segment elevation, however it will not have reciprocal changes
Dissecting Thoracic Aortic Aneurysm
Heparin could prove fatal if given to this patient. Nitroglycerin is given with caution, if at all, due to the heart’s attempt to compensate for decreased afterload by increasing heart rate and contractility. This would cause undue stress on a weakened area of the aorta.
Dissecting Thoracic Aortic Aneurysm
