ECGs Flashcards
3 ECG features of dextrocardia
Inverted P wave in Lead I
RAD
Loss of R wave progression
Describe depolarisation in bundle branch block
depolarisation has to come via a separate route to polarise the other ventricle.
ie. in LBBB, depolarisation comes from the right ventricle
How does bundle branch block cause its characteristic pattern in ECG? Use RBBB to explain
In RBBB depolarisation has to come from the LV
First see R wave from depolarisation of LV, followed by a slower second R wave from depolarisation of RV= M shaped wave in V1 (closest to RV)
W in V6 is recipricol
Give 4 features of Digoxin use on ECG
Down sloping ST depression ‘reverse tick, scooped out’
Flattened/ inverted T waves
Short QT interval
Arrhythmias e.g. AV block, bradycardia
Name 2 congenital causes of long QT syndrome
Jervell-Lange-Nielsen syndrome
Romano-Ward syndrome
Which cardiac drugs can cause long QT?
Amiodarone
Sotalol
Class 1a anti arrhythmic drugs: Flecainide, Lidocaine
Which psychiatric drugs can cause long QT?
TCAs
SSRIs
Haloperidol
List 5 non-cardiac/ psych drugs that can cause long QT?
Methadone
Ondansetron
Chloroquine
Terfenadine
Erythromycin
Why is long QT syndrome important to recognise?
May lead to VT or TdP
Can cause collapse + sudden death
What is the usual mechanism by which drugs cause long QT?
Blockage of K+ channels
What is the management of patients with long QT?
Avoid drugs which prolong QT + other precipitants e.g. strenuous exercise
B-blockers (NOT sotalol)
ICD in high risk cases
What is Wellen’s syndrome? How may it present?
ECG pattern caused by high-grade stenosis in LAD
Pain may have resolved at time of presentation + cardiac enzymes may be normal/ minimally elevated
3 ECG features of Wellen’s syndrome
Biphasic or deep T wave inversion in V2-3
Minimal ST elevation
No Q waves
