ECG

Question 1

features of hypokalaemia

Answer 1

U waves
small or absent T waves (occasionally inversion)
prolong PR interval
ST depression
long QT

Question 2

Which part of the ECG complex corresponds with the closure of the mitral valve?

Answer 2

QRS complex

Question 3

S3 sound caused by what

Answer 3

diastolic filling of ventricles

Question 4

S4 sound caused by

Answer 4

atrial contraction against stiff ventricle coinciding with P wave on ECG

Question 5

Hypocalcemia is associated with QT interval prolongation; Hypercalcemia is associated

Answer 5

with QT interval shortening

Torsades to pointes

Long QT syndrome (LQTS) is an inherited condition associated with delayed repolarization of the ventricles. It is important to recognise as it may lead to ventricular tachycardia/torsade de pointes and can therefore cause collapse/sudden death. The most common variants of LQTS (LQT1 & LQT2) are caused by defects in the alpha subunit of the slow delayed rectifier potassium channel. A normal corrected QT interval is less than 430 ms in males and 450 ms in females.

Question 6

Electrophysiology studies are being carried out in a girl with suspected Wolff-Parkinson-White syndrome, who has suffered repeated episodes of sudden-onset palpitations. This procedure involves intra-cardiac catheterization to measure the electrical activity of the heart and to assess the different parts of the conduction pathway.

Which part of this pathway has the fastest conduction velocity?

Answer 6

purkinje fibres

Question 7

trisomys what common defect

Answer 7

ventricular septal defect

Question 8

what causes long QT syndrome

Answer 8

amiodarone, sotalol, class 1a antiarrhythmic drugs
tricyclic antidepressants, selective serotonin reuptake inhibitors (especially citalopram)
methadone
chloroquine
terfenadine
erythromycin
haloperidol
ondanestron

electrolyte: hypocalcaemia, hypokalaemia, hypomagnesaemia
acute myocardial infarction
myocarditis
hypothermia
subarachnoid haemorrhage

Question 9

Tall P waves
U waves
T wave depression
Tall tented T waves

Answer 9

hypokalaemia

Question 10

delta was

Answer 10

Wolfe-Parkinson-White

Question 11

Tall tented T waves

Answer 11

hyperkalaemia

ECG findings
Peaked or 'tall-tented' T waves (occurs first)
Loss of P waves
Broad QRS complexes
Sinusoidal wave pattern
Ventricular fibrillation