EKG -- Random flashcard-able thoughts
How long should a PR Interval be (in boxes and time)
Under 200 msec
one big box
How long should a QRS interval be (in boxes and time)
Under 120 msec
3 small boxes
How long should the QT interval be?
Under 500 msec
two and a half big boxes
15 big boxes on the EKG =
3 seconds
Rhythm with a p in front of all of them
Sinus Rhythm
Rhythm described as gravelly
Atrial Fibrillation
Rhythm described as sawtooth pattern
Atrial Flutter
Rhythm with upside down Ps
Junctional Rhythm
A heart with an axis between 0 and 90 is considered….
normal
A heart with an axis less than zero is considered…
L Axis Deviated
A heart with an axis greater than 90
R Axis Deviated
A heart in its normal axis will have which two leads positive
I
aVF
If lead two is isoelectric or more negative, the heart is pointed to an area more negative than -30. This is called…
L Anterior Fasicular Block
Sinus bradycardia occurs at…
60 bpm
Best lead to look for P waves?
V1
Sawtooth pattern of atrial flutter is best observed in…
II, III, aVF
What happens in atrial flutter with 2:1 conduction
Waves are goign at about 300 bpm, but the sinus can’t depolarize that fast, so it triggers a beat on every other one
Isometric precordial lead?
V3
RBB and LBB Blocks typically have an upright t wave on which side? a downward wave on which side?
Upward on the side that electricity is moving toward, down on the side its moving away from
Other than the T wave changes, what EKG changes are associated with L and R Bundle Block and Why.
Elongation of the QRS (M sign) beyond 120 msec
Delayed conduction coming across the myocardium
Type of cardiomyopathy that is louder when standing up?
Hypertrophic Cardiomyopathy
Associated with children
What do you see in Left Posterior Fasicular Block?
Still in the normal 0 to 90, but shifts left
Look compared to an old EKG sitting around
Four types of AV block
1st d – Fixed PR prolongation
2TI – Gradual PR Prolongation
2TII – Unpredictable AV block
3rd d – AV dissociation
Difference in the location of damage for Weinchebach and Mobitz?
W – Above the His/Purkinge
M – Below
Steps of Heart attack as seen from EKG (5)
- Hyperacute T Waves (usually before hospital)
- ST Elevation (aka Current of Injury
- Q wave (as cells die)
- ST return, T wave inversion
- Loss of R wave
EKG finding seen for left ventricular aneurysm?
Persistent ST seg elevation + Q wave
What vessel is blocked in an MI seen on leads II, III, aVF
Inferior Leads
Inferior MI = RCA or Distal L Circumflex
What vessel is blocked in an MI seen on leads V1-V5
Anteroseptal/anterior leads
LAD
What vessel is blocked in an MI seen on leads I, aVL, V6?
Lateral Leads
Proximal L Circumflex
ST depression can be used for…
Gauging the size of the MI
Sign of previous MI
Q waves
Persistent ST and T wave inversion
What should you think of with ST elevation in II, III, aVF and also V5 and V6.
Blockage of the L Circumflex Artery in a L dominant heart
