Cardio - ECG Pathology, ST elevation/depression, T-wave abnormalities

Question 1

ST - segment and abnormalities, criteria for ST segment elevation?

Answer 1

1. 1mm of ST segment elevation in ANY of 2 contiguous leads, except for V2-V3
2. 2mm of ST segment elevation in V2-V3

Measure from isoelectric line, how many mm

Question 2

Differentials of ST-elevation?

Answer 2

STEMI

Pericarditis

PE

LBBB

LV hypertrophy

LV aneurysm

Benign Early Repolarisation

Question 3

ST-depression criteria, the different types and criteria for confirming the presence of one?

Answer 3

Downsloping ST-depression

Horizontal ST-depression (most concerning for ischaemia)

Upsloping ST-depression

1. Measure how may mm below it is in relation to isoelectric line
2. Greater than or equal to 0.5mm in ANY 2 contiguous leads - ST-depression

Question 4

Differentials for ST-depression?

Answer 4

NSTEMI

Posterior MI

LBBB

Digoxin toxicity

LVH with strain

Question 5

Definition of what classifies as an S wave?

Answer 5

S wave has to go down through isoelectric line and back up, so if it doesn’t do this, it isn’t an S wave, could be a J wave

Question 6

Differentials of J waves?

Answer 6

Benign Early Repolarisation

Hypothermia

Hypercalcaemia

Brugada syndrome

Question 7

Different types of T wave abnormalities?

Answer 7

T wave inversion

Hyperacute T waves

Biphasic T waves

Flat T waves

Peaked T waves

Question 8

T wave inversion, what is it, differentials?

Answer 8

Deflection that is greater than or equal to 1mm below isoelectric line

T wave inversion in avL only, suspicion of inferior MI

Differentials:

1. P.E
2. LVH strain
3. Increased ICP
4. BBB
5. Ischaemia

Question 9

Hyperacute T waves, what is it, differentials

Answer 9

Tall, broad base, asymmetrical peak, can fit QRS in hyperacute T-wave

Differentials:

1. Vasospasm
2. Early STEMI

Question 10

Biphasic T waves

Answer 10

Can be +ve deflection followed by -ve deflection

OR

-ve deflection followed by +ve deflection (attached image)

Differentials:

1. Ischaemia (+ve to -ve)
2. Hyperkalaemia (-ve to +ve)

Question 11

Flat T waves, what is it, differentials

Answer 11

Flat T wave is somewhere at least between -1mm of deflection downwards and 1mm of deflection upwards

Differentials:

1. Ischaemia
2. Hypokalaemia

Question 12

Peaked T waves, what is it, differentials

Answer 12

Tall, narrow base, relatively symmetrical peaked T wave

>10mm in height

Differentials:

1. Hyperkalaemia
2. Hypermagnesemia
3. Ischaemia