Abnormal ECG

Question 1

What can cause too tall P waves?

Answer 1

right atrial abnormality - pulmonary disease, congenital heart disease

Question 2

Characteristics of too tall P waves

Answer 2

> 2.5 squares tall
Tall peaked P waves
normal duration

Question 3

Characteristics of too broad P waves

Answer 3

> 3 squares wide
broad P waves
normal height

Question 4

What can cause too broad P waves?

Answer 4

left atrial abnormality - valve disease, hypertension, coronary artery disease, cardiomyopathy

Question 5

Too short PR interval causes

Answer 5

low atrial pacemaker
accessory pathway

Question 6

Too long PR interval or P wave not conducted cause

Answer 6

AV block

Question 7

Causes of wide QRS complex

Answer 7

supraventricular origin:
- bundle branch block
- brugada pattern
- ‘toxic’ conduction delay
- wolff-parkinson-white pre-excitation

ventricular origin:
- ventricular ectopic beat
- ventricular paced beat

Question 8

Wolff-Parkinson-White ECG

Answer 8

short PR
wide QRS
delta wave

Question 9

ECG features of RBBB

Answer 9

V1 = RSR’ pattern (M)
V6 = QRS can be normal, or slurred S wave (W)

[MarroW]

Question 10

ECG features LBBB

Answer 10

V1 = QRS complex has the appearance of a W (the rS’ pattern)
V6 = QRS has the appearance of M (due to a notched R wave)

WilliaM

Question 11

Causes of LBBB

Answer 11

aortic stenosis
ischaemic heart disease
hyperkalaemia
digoxin toxicity
myocardial infarction

Question 12

Causes of RBBB

Answer 12

right ventricular hypertrophy
pulmonary embolism
ischaemic heart disease
congenital heart disease
normal variant

Question 13

What is the difference between pathological and physiological Q waves?

Answer 13

short and small = normal
wide and/or deep = pathologic

Question 14

ST depression causes

Answer 14

ischaemia
posterior MI
repolarisation abnormalities

Question 15

ST elevation causes

Answer 15

STEMI
pericarditis
BBB
high take off

Question 16

Where does ST elevation occur in a STEMI?

Answer 16

regional ST elevation in a STEMI

Question 17

Where does ST elevation occur in pericarditis?

Answer 17

widespread ST elevation

Question 18

NSTEMI/Unstable Angina ECG

Answer 18

acute = T wave inversion, ST depression

weeks later = ST +T normal, no Q waves

Question 19

Too tall T wave causes

Answer 19

ACS
hyperkalaemia

Question 20

Inverted T wave causes

Answer 20

may be normal
myocardial disease (ischaemia, infarction, cardiomyopathy)
ventricular hypertrophy
bundle branch block

Question 21

What does the QT interval represent?

Answer 21

time taken for the ventricles to depolarise and then repolarise

Question 22

What are both short and long QT intervals associated with?

Answer 22

increased risk of ventricular arrhythmias (particularly polymorphic VT or Torsades de Pointes)