ECG

Question 1

what side is I and III on the ECG?

Answer 1

I = left 
III = right

Question 2

what nervous fibres supply the ventricles after His bundle?

Answer 2

purkinje fibres

Question 3

what is the rhythm for regular QRS but no p waves?

Answer 3

nodal rhythm

Question 4

what does R axis deviation suggest ?

Answer 4

anterolateral MI 
RVH
PE
WPW (wolff parkinsons white syndrome)
ASD secundum

Question 5

what does bifid p waves suggest?

Answer 5

LA hypertrophy

Question 6

what does peaked p waves suggest?

Answer 6

RA hypertrophy

• as the sinus node starts in the R atrium the signal will be stronger if the muscle is hypertrophied

Question 7

what causes LA hypertrophy?

Answer 7

HTN
AS
MR
MS

Question 8

what are the measurements of pathological Q wave?

Answer 8

> 1mm wide and > 2mm deep

Question 9

state some cause of wide QRS?

Answer 9

Ventricular initiation
􏰁 Conduction defect
􏰁 WPW

Question 10

what time is prolonged QRS?

Answer 10

> 120ms

Question 11

what time is prolonged PR interval?

Answer 11

> 200ms

Question 12

what causes shortened PR interval?

Answer 12

Accessory conduction: e.g. WPW 􏰁
Nodal rhythm
􏰁HOCM

Question 13

where is the QT interval from and to?

Answer 13

Start of QRS to end of T wave

Question 14

what time is prolonged Qtc interval?

Answer 14

> 420ms

Question 15

what time is shortened Qtc interval?

Answer 15

<380ms

Question 16

what causes short QTc?

Answer 16

Digoxin
􏰁 β-B
􏰁 Phenytoin

Question 17

what causes prolonged QTc?

Answer 17

Toxins
􏰂 - Macrolides
􏰂 - Anti-arhythmics (Ia/III): quinidine, amiod
􏰂 - TCAs
􏰂-  Histamine antagonists

􏰁 Inherited: e.g. Romano-Ward, Jervell ( ̄c SNHL) 􏰁

Ischaemia

􏰁 Myocarditis

􏰁 Mitral valve prolapse

􏰁 Electrolytes: ↓Mg, ↓K, ↓Ca, ↓ temp

Question 18

state some causes of ST elevation?

Answer 18

Acute MI

􏰁 Prinzmetal’s angina

􏰁 Pericarditis: saddle-shaped 􏰁

Aneurysm: ventricular

Question 19

what is 􏰁 Prinzmetal’s angina?

Answer 19

often referred to as “variant” angina, is a temporary increase in coronary vascular tone (vasospasm) causing a marked, but transient reduction in luminal diameter.

Question 20

what causes U waves?

Answer 20

hypokalaemia

Question 21

what causes J waves ?

Answer 21

hypothermia < 32OC 􏰂

SAH (subarachnoid haemorrhage)

􏰂 Hypercalcaemia

Question 22

where does the U wave occur?

Answer 22

after the T wave

Question 23

where does J wave occur?

Answer 23

between QRS and ST segment

Question 24

state some cause RBBB?

Answer 24

inferior MI 
ASD, VSD, Fallots 
RVH 
PE 
Cor pulmonale

Question 25

what is Cor pulmonale ?

Answer 25

abnormal enlargement of the right side of the heart as a result of disease of the lungs or the pulmonary blood vessels.

Question 26

state some cause LBBB?

Answer 26

fibrosis LVH (caused by AS, HTN) inferior MI

Question 27

what is Bifascicular Block?

Answer 27

RBBB + L axis deviation

Question 28

what is Trifascicular Block?

Answer 28

RBBB + LAFB (Left anterior fascicular block) + 1st degree AV block

Question 29

what is seen on ECG with Junctional Escape?

Answer 29

no p waves normal QRS 40-60bpm

Question 30

what is seen on ECG with Ventricular Escape?

Answer 30

may have regular p waves or absent p waves wide QRS complex 20bpm

Question 31

what is seen on ECG with Ventricular Extrasystole?

Answer 31

No P wave. | Wide QRS and abnormal T wave.

Question 32

what is seen on ECG with Atrial Flutter?

Answer 32

“Saw-toothed” baseline as atria contract @ 300bpm. AVN can’t conduct > 200bpm 􏰄 AV block occurs. Normal QRS

Question 33

what is seen on ECG with Atrial Fibrillation?

Answer 33

No P waves – irregular line Irregularly irregular QRS

Question 34

what is seen on ECG with ventricular Fibrillation?

Answer 34

No P waves Regular, wide QRS No T waves

Question 35

what are characterised signs of VT?

Answer 35

Hx: recent infarction 􏰀 Atrioventricular dissociation 􏰀 Broad QRS complexes (>140ms) 􏰀 Concordant QRS direction in V1-V6 􏰀 Fusion and capture beats

Question 36

what is seen on ECG with wolff parkinsons white syndrome?

Answer 36

Short PR interval Slurred upstroke of QRS called a delta wave (V3/4).

Question 37

what can be seen on ECG for PE?

Answer 37

SI QIII TIII (rare) - deep S wave in I (RAD) - pathological Q in III - T inversion in III

Question 38

what is seen on ECG with Brugada syndrome?

Answer 38

RBBB

Question 39

what are some causes of bradycardias? (DIVISION)

Answer 39

drugs ischaemia vagal hypertonia infection sick sinus syndrome infiltration (restrictive/dilated) hypO thyroidism/kalaemia/thermia neuro (increased ICP) septal defect (premum ASD) surgery/ catheterisation

Question 40

what conditions require Permanent pacing?

Answer 40

``` Mobitz II 􏰀 Complete AV block 􏰀 Sick sinus 􏰀 AF 􏰀 Drug-resistant tachyarrhythmias ```

Question 41

what is the management of SVT

Answer 41

sedate + DC cardioversion Vagal manoeuvres (carotid sinus massage, valsalva) If manoeuvres unsuccessful, give adenosine while recording rhythm strip ``` If adenosine fails, choose from: 􏰁 Digoxin 􏰁 Atenolol 􏰁 Verapamil (not if on β-blocker) 􏰁 Amiodarone ``` 􏰀 If unsuccessful → DC cardioversion

Question 42

what are SEs of adenosine

Answer 42

Transient chest tightness, dyspnoea, flushing, headache

Question 43

state some broad complex tachycardias ? (Rate >100bmp, QRS width > 120ms)

Answer 43

VT Torsades de points S V T with BBB

Question 44

state some causes of VT?

Answer 44

infarction myocarditis increased QTc mitral prolapse, aortic stenosis (systolic) digoxin, antiarrhythmias cardiomyopathy (dilated) low K, Mg, O2, acidosis

Question 45

what is the action of adenosine ?

Answer 45

temporary AVN block