EKG Flashcards
P wave
Atrial depolarization begins
PR-interval
Atrial depolarization complete
Atrial depolarization + Ventricula depolarization
QRS complex
ST-segment
Ventricular depolarization complete
T wave
Ventricular repolarization begins
Depolarization begins (Atria)
P wave
Depolarization complete (Atria)
PR interval
Repolarization (Atria)
QRS
Depolarization begins (Ventricle)
QRS
Depolarization complete (ventricular)
ST segment
Repolarization begins
T wave
Repolarization complete
After T wave
PeRicarditis
can cause PR-interval depression
Peaked T-waves
myocardial ischemia, kyperkalemia, LV hypertrophy, intercranial bleeding
PR segment
isoelectric line, reference point for measuring ST elevation
Hypokalemia (ECG changes)
increased PR interval, increased QT interval, T wave flattening, U wave
Hyperkalemia (ECG changes)
peaked T waves, P wave flattening, PR prolongation, QRS prolongation , V-fib
Hypercalcemia
shoRt QT interval
Hypocalcemia
lOng QT interval
Hypermagnesemia
heart block and arrest
HypOmagnesemia
lOng QT interval (torsades risk)
RCA: Inferior Heart
II, III, aVF
Circumflex: Left Lateral Heart
I, aVL, V5, V6
LCA: Anterior Heart, LAD
V1-V4
Bipolar leads
I, II, III
Limb leads
aVR, aVL, aVF
Pericordial
V1-V6
The mean electrical vector tends to point towards…
areas of hypertrophy (more tissue to depolarize) and away from areas of myocardial infarction
If lead I and aVF point up then…
the axis is normal (two thumbs up)
leads (R)eaching towards one another (I points down and aVF points up)
(R)ight axis deviation
If leads are (L)eaving each other then…
(L)eft axis deviation
If both leads point down then…
Extreme Right axis deviation (two thumbs down)
Normal axis voltage
between -30 and +90
more negative than -30
LEFT axis deviation
more positive than +90
RIGHT axis deviation
Causes of Right Axis Deviation
COPD, acute bronchospasm, for pulmonale, pulmonary HTN, pulmonary embolus
Causes of Left Axis Deviation
Chronic HTN, LBBB, Aortic stenosis, Aortic insufficiency, MR