Winter ECG Quiz 2 Flashcards
Which leads look at the septal wall?
V1, V2
Which leads are positioned to look at the inferior wall of the left ventricle?
II, III, AVF
Which leads look at the anterior wall of the left ventricle?
V3, V4
Which leads look at the lateral wall of the left ventricle?
I, aVL, v5, v6
Which areas of the heart are perfused by the LAD?
Anterior wall of L. Ventricle
Lateral wall of L. Ventricle
Intraventricular septal wall
Which areas of the heart are perfused by the LCA (left circumflex artery)?
Inferior wall of L. Ventricle
Lateral wall of L. Ventricle
Posterior wall of L. Ventricle
R. Ventricle
Which areas of the heart are perfused by the R. Coronary artery?
Inferior wall of the L. Ventricle
Posterior wall of the L. Ventricle
R. Ventricle
How much time does a 12-lead represent?
10 continuous seconds (each lead is 2.5 seconds)
What is normal calibration of an ECG?
1mV=?mm
1mV=10mm
Where is the best location on an ECG strip to locate the isoelectric line?
The TP segment
In which leads will there be upright pwaves if a sinus rhythm?
I, II, aVF, V4, V5, V6
Which lead will show an inverted P if it is a sinus rhythm?
aVR
What is the aVR lead good for?
Detecting the presence of a P-wave
Which 2 leads are best for determining whether or not it is a sinus rhythm? (P-wave)
Upright in II
Inverted in aVR
What are the 3 reasons for a p-wave to NOT be inverted in aVR?
- Junctional rhythm
- Lead reversal
- Dextrocardia (heart on the right)
What should you do if you have upright pwaves in both aVR and II?
Check your leads - they are likely reversed
What is considered “significant” elevation or depression?
> or = 1mm
In addition to coronary clots, name 5 other causes of MI.
Coronary artery spasm Cocaine use Acute volume overload Acute respiratory failure Trauma
What are some ECG signs of ischemia?
ST depression
Flipped t-wave
What are 2 ECG signs of cardiac “injury”?
ST elevation
Flipped T
What are 3 ECG findings of cardiac tissue death (infarction)?
ST elevation
Flipped T
Pathological Q
What constitutes “contiguous” leads?
Any 2 adjacent precordial leads
Inferior: II, III, aVF
Lateral: I, aVL, V5, V6
Right sided MI’s most often occur in conjunction with which other part of the heart? Why?
Inferior - their blood supply comes from the same place.
Septal MI: which artery is involved?
Which other area of the heart is usually involved in conjunction with a septal MI?
LAD
Anterior
Where will you typically see ST elevation in an anterior MI?
V3, V4
What artery is involved in an anterior MI?
LAD
An anterior MI almost always occurs in conjunction with what?
Septal or lateral MI
A lateral MI can occur in conjunction with what other part of the heart?
Any part!
A lateral MI shows ST elevation in which leads?
I, aVL, V5, V6
Which artery is involved in a lateral MI?
LAD
What types of t-wave abnormalities may be associated with an AMI?
Hyper acute
Inverted
What defines a hyper acute t-wave?
> 10mm in the precordial leads
>6mm in limb leads
At what stage of a STEMI are hyper acute t-waves typically seen?
Early! They are commonly missed because they are short lived.
In the presence of a STEMI, when do you typically see pathological Q waves?
Pathological Q waves are usually the last thing to develop.
6 hrs after the start of an MI at the earliest
What are the 2 areas of the heart a traditional 12-lead is not designed to view?
Right side (R. Ventricle MI) Posterior MI
R. Sided MI’s are rarely isolated and are most commonly associated with which type of MI?
Inferior MI
What ECG findings should give a high index of suspicion for a posterior MI?
ST depression in V1 & V2
