ECG workshop

Question 1

How can LBBB and RBBB be differntiated ?

Answer 1

LBBB down In V1and up in V6

RBBB is up in V1 and down in V6
-terminal (S) portion widened/slurred in V6

QRS needs to also be wide though

Question 2

What constitutes a wide QRS complex and what can this suggest ?

Answer 2

Onset to offset of QRS greater than three small boxes (120ms) is wide
-Can be due to BBB

Question 3

When does ST elevation not suggest MI

Answer 3

ST elevation is less suggestive of myocardial infarction in the absence of ischemic symptoms and reciprocal ST depression
-ST elevation from STEMI in one area causes ST depression in leads of opposite territory

Question 4

What is aVR ?

Answer 4

Reference lead; means nothign, if its weird its probably on wrong
-if its QRS goes up its probbaly on wrong

Question 5

Which lead is checked for P waves and sinus rhythm ?

Answer 5

Lead II
-Sinus rhythm is P wave before every QRS

Question 6

What is a differential diagnosis for an ECG which shows ST elevation in terrioties of the heart supplied by differnt coronary arteries ?

Answer 6

Pericarditis
-young guy with virus and loads of st elevations around the place but which don’t make sense for MI
-MI not really making sense if territories of RC and LAD blocked or if no reciprocal changes

Go learn which arteries supply which surfaces

Question 7

Where should you look next if one lead rhythm is weird ?

Answer 7

The other leads of the same territory

Question 8

What does this ECG show ? Very slow, broad qrs, no p waves, irregular

Answer 8

Escape beats

Question 9

How does third degree heart block affect P waves ?

Answer 9

P waves follow their own rhythm unrelaed to QRS
-P waves may march into and overlap with QRS complexes as rhythms usually regular but independent

Question 10

How do ectopic beats present on an ECG ?

Answer 10

Ectopic beats cause pauses; here, 3 normal beats then an ectopic and a longer pause, three normal beats … etc

Question 11

What does long QT syndrome look like on an ECG ?

Answer 11

Big sloping T waves, risk of sudden death

Question 12

How does heart block with Afib affect the ECG ?

Answer 12

Slow and regular while in AF means complete heart block