Arrhytmias + ECG

Question 1

What is an arrhythmia

Answer 1

An abnormality in the cardiac rhythm generated by abnormal electrical conduction

Question 2

3 main types of arrhythmia

Answer 2

Supraventricular
Ventricular
Atrioventricular

Question 3

Supraventricular arrhythmia - 2 main types

Answer 3

Supraventricular tachycardia
Bradycardia

Question 4

Supraventricular tachycardia - 5 types

Answer 4

Atrial fibrillation
Atrial flutter
AV tachycardia - AVNRT + AVRT
Ectopic atrial tachycardia

Question 5

Supraventricular bradycardia - 2 types

Answer 5

Sinus bradycardia
Sinus pauses

Question 6

Ventricular arrhythmias - 5 types

Answer 6

Ventricular ectopics
Premature ventricular complexes
Ventricular tachycardia
Ventricular fibrillation
Asystole

Question 7

Atrioventricular - 4 types

Answer 7

AV nodal reentry tachycardia
AV reentry
AV reciprocating
AV block

Question 8

Symptoms of arrhythmias - 9

Answer 8

Anxiety
Palpitations
Dyspnoea - difficult breathing
Faintness
Shock
Syncope

Angina
Heart failure

Sudden cardiac shock

Question 9

Investigations into arrhythmias

Answer 9

12 lead ECG
+stress ECG
Bloods
CXR
Echocardiogram

24 hour ECG
Check for MI + exercise related arrhythmias
Event recorder
Induce clinical arrhythmia
Electrophysiological study

Question 10

ECG - what it does

Answer 10

Measures the extracellular current which changes due to alterations in the membrane potential of myocardial tissue

Question 11

Electrode placement - V1 to V6

Answer 11

V1 - 4th intercostal space at right sternal angle
V2 - 4th intercostal space at left sternal angle
V3 - midway between V2 and V4 electrodes
V4 - 5th intercostal space in the midclavicular line
V5 - left anterior axilaryline at same horizontal level as V4
V6 - left mid-axilary line at same horizontal level as V4 + V5

Question 12

Placement of limb electrodes

Answer 12

Red - Right Arm - ulnar styloid process
Yellow - Left Arm - ulnar styloid process
Green - Left Leg - on the medal or lateral malleolus
Black - Right Leg - on the medial or lateral malleolus

Question 13

Lead 2 explaination - PQRST waves

Answer 13

• P wave – atrial depolarisation moving towards the recording electrode
• Q wave – left to right depolarisation of the interventricular septum moving slightly away from the recording electrode
• R wave –depolarisation of the main ventricular mass moving towards the recording electrode
• S wave – depolarisation of ventricles at the base of the heart moving away from the recording electrode
• T wave – ventricular repolarization moving in a direction opposite to that of depolarisation accounts for the usually observed upward deflection

Question 14

Inferior leads

Answer 14

II
III
aVF

Question 15

Lateral leads

Answer 15

I
aVL
V5
V6

Question 16

Anterior leads

Answer 16

V3
V4

Question 17

Septal leads

Answer 17

V1
V2

Question 18

Axis of the heart - how to know

Answer 18

If both aVF and lead I spike upwards heart is in normal axis

If only I spikes up - Left axis deviation
If only aVF spikes up - Right axis deviation

If both aVF and lead I spike down - extreme right axis deviation

Question 19

ECG cannot detect

Answer 19

MI
Stable angina

Question 20

7 questions to work out rate and rhythm

Answer 20

Is electrical activity present
Is rhythm regular or irregular
What is heart rate (300/?)
P waves present ?
What is PR interval (0.12-0.2)
Is each P wave followed by QRS complex
Is QRS duration normal (<0.1)