ECG and Arrythmias

Question 1

what are the ECG changes over time seen in a STEMI

Answer 1

Onset of pain = normal

Within 1 hour = noticeable ST elevation

Following treatment = t wave inversion

24 hours = St segment returned to baseline, T wave inversion persists

Days, months after = deep q wave (negative before R) develops indicating tissue death

Question 2

what does a convex ST elevation indicate

Answer 2

pericarditis (saddle shape)

Question 3

what is a J wave and what does it indicate

Answer 3

positive deflection inbetween QRS and T wave

hypothermia

Question 4

what is torsades pointes

Answer 4

‘twisted dough’ polymorphic VT, with a series of large amplitude beats followed by a series of small amplitude beats in a sine wave pattern (looks like the AM cover)

Question 5

what is in brugada syndrome

Answer 5

Prolonged PR interval, double-peaked ST elevation + t wave inversion – usually in leads v1-3 with a low-normal BPM + wide QRS in some leads

Question 6

what is the risk in brugada syndrome and how is it managed

Answer 6

VT, pacing

Question 7

what is the treatment of torsades pointes

Answer 7

magnesium sulphate

Question 8

what is the fire rate of each foci in the heart

Answer 8

SAN = 60-100 bpm

Atrial foci = 60-80 bpm

Junctional foci = 40-60 bpm

ventricular foci = 20-40 bpm

Question 9

how does a posterior MI present

Answer 9

bradycardia with severe ST depression in leads v1-4 with a history indicating this