Lecture 6- ST and Hypertrophy

Question 1

Where QRS complex and ST segment meet?

Answer 1

J point

Question 2

One of the most important aspects of an ECG?

Answer 2

ST segment

Question 3

Describe normal ST segment

Answer 3

ST segment should be at baseline

ST segment is smooth and blends into T wave

Question 4

Describe abnormal ST segment changes in regards to baseline

Answer 4

Changes of > 2 mm in 2 or more leads = abnormal
(Changes of < 1 mm is normal in limb leads)
*imp to listen to pt

Question 5

Pathologic ST seg changes?

Answer 5

ST depression = ischemia or NSTEMI

ST elevation = injury/infarct (STEMI)

Question 6

Benign ST seg changes?

Answer 6

Pericarditis (↑)
Early Repolarization (↑)
Ventricular Hypertrophy with strain (↑ or ↓)
Bundle Branch Blocks (↑ or ↓)

Question 7

benign or pathologic? ST segment elevation with downward concavity

Answer 7

pathologic (sad face, downward curve)

Question 8

benign or pathologic? ST segment elevation with upward concavity , especially with notching of J point

Answer 8

benign (happy face, upward curve)

Question 9

Normal T wave should be symmetrical or asymmetrical?

Answer 9

asymmetrical

Question 10

Symmetrical T waves (usually pathologic) can be an indication of:

Answer 10

Ischemia/infarct
Hyperkalemia (tall and narrow)
Intracranial hemorrhage (broad and wide)

Question 11

T wave size is abnormal if:

Answer 11

> 2/3 height of R wave

Question 12

Tall T waves can indicate

Answer 12

Ischemia/Infarct
CNS events
Hyperkalemia

Question 13

T waves can be positive, negative, biphasic, or flat. Which leads are they usually positive in? Negative?

Answer 13

Lead I, II, V3-V6;

negative in aVR

Question 14

Biphasic t waves- what is the significance of the first part of the wave being either negative or positive?

Answer 14

If first part of T wave positive, more likely to be benign

If first part of T wave negative, more likely to be a sign of pathology

Question 15

Ischemia or NSTEMI features:

Answer 15

Flat or downsloping ST segment

Symmetrical inverted or biphasic T waves

Question 16

STEMI features

Answer 16

Flat or downward concave
-ST segment- “frowny face”/“tombstoning”
Symmetrical T waves (↑ or↓)

Question 17

Diffuse ST segment elevation- upwardly concave
PR segment depression
Notching at the end of QRS complex
….characteristic of what?

Answer 17

Pericarditis (benign ST elevation)

• will be this in most leads
• chest pain laying down, with inspirations, cardiac rubs
• common in young, black males

Question 18

Describe early repolarization

Answer 18

Similar pattern to pericarditis except no significant PR segment depression
Benign ST segment elevation- upwardly concave
Notching at end of QRS complex
Generally found in younger people

Question 19

Right Atrial Enlargement?

Answer 19

P wave in lead II:
> 2.5 mm high
Peaked shape = “P pulmonale”

P wave in lead V1:
If biphasic, positive half taller and wider than negative half

Question 20

Left Atrial Enlargement?

Answer 20

P wave in Lead II:
> 0.12 seconds long
M shaped = “P mitrale”
Camel humps- at least one small box between

P wave in Lead V1:
Biphasic with second half at least 1 small box wide and deep

Question 21

Biatrial Enlargement?

Answer 21

A combination of criteria for RAE + LAE

Question 22

Left Ventricular Hypertropy?

Answer 22

Deepest S wave in V1 or V2 + Tallest R wave in V5 or V6 ≥ 35 mm
(high amplitude in precordial leads, also would need an echo)

Question 23

When can LVH criteria not be used?

Answer 23

in the presence of LBBB, WPW, ventricular rhythms, and certain electrolyte and drug effects that alter the QRS complex

Question 24

What if R waves from different leads are overlapping on your tracing?

Answer 24

Repeat tracing at half-standard calibration (check box on right hand side)

Question 25

Define “strain”

Answer 25

Repolarization abnormality due to right ventricular hypertrophy or dilatation.

Question 26

Right Ventricular Hypertrophy?

Answer 26

Look at leads V1 and V2
R wave in these leads at least as tall as the depth of S wave (R:S ratio ≥ 1)
Early transition zone

Question 27

Right Ventricular Strain criteria?

Answer 27

RVH criteria: ↑R:S ratio in V1 and V2
Strain pattern:
ST depression with concave, downward slope
Flipped, asymmetric T wave

Question 28

Left Ventricular Strain criteria?

Answer 28

LVH criteria
Strain pattern:
Most pronounced in lead with deepest/tallest QRS complexes

Question 29

ST and T wave with BBB

Answer 29

T wave should always be in the opposite direction of the last wave of the QRS complex = discordance
If T wave in same direction as last wave of QRS = concordance, which signals ischemia unless chronic