Non - Cardiac Conditions And The ECG

Question 1

What happens to the QT interval if the heart rate increases ?

Answer 1

The QT interval decreases

Question 2

What happens to thE QT interval if the HR Decreases?

Answer 2

The QT interval increases

Question 3

What is QTC

Answer 3

QTC = QT correction , as in the QT is corrected for the specific heart rate

Question 4

How do you work out QTC?

Answer 4

QTc = QT divided by PR (squared)

Question 5

What ECG features are associated with Cerebral Haemorrhage?

Answer 5

• Bradycardia
• Cerebral T waves (deep , very wide and depressed T waves) - easily observed in precordial leads (V2-V6)
• prolonged QT interval

Question 6

common ECG features of Pulmonary Embolism (PE) ?

Answer 6

1) Sinus Tachycardia (44%)
2) right ventricular strain pattern (34%)
3) S1, Q3, T3 (20%)
4) complete or incomplete RBBB (18%)
5) right Axis Deviation (16%)
6) Non-specific ST segment and T wave changes (50%)

Simultaneous T wave inversion in lead 3 and V1 is only observed in 1% of patients with ACS but in 88% of patients with PE

ACS is rarely associated with Tachycardia

Question 7

How to tell PE and ACS apart easily ?

Answer 7

Simultaneous T wave inversion in lead 3 and V1 is only observed in 1% of patients with ACS but in 88% of patients with PE

ACS is rarely associated with Tachycardia

Question 8

Hypothermia ECG changes?

Answer 8

• Bradyarrythmias
• Osbourne waves (looks a bit like a north directly after QRS but is the T wave)
• prolonged PR , QRS and QT intervals
• shivering artefact
• Ventricular Ectopics

Question 9

What is Hyperkalaemia?

Answer 9

Defined as a Serum Potassium level of > 5.2mmol/L

• ECG CHANGES ARE USUALLY ASSOCIATED WITH MODERATE Hyperkalaemia of > 6.0mmol/L

Question 10

Hyperkalaemia ECG features?

Answer 10

• Peaked T waves (tall)
• P wave widening/flattening and PR prolongation
• Bradyarrhythmias
• bundle branch blocks
• QRS widening with bizarre QRS morphology

Question 11

What is Hypokalaemia?

Answer 11

Potassium levels too low <3.5mmol/L

Question 12

ECG features of Hypokalaemia ?

Answer 12

• increased P wave amplitude
• prolongation of PR interval
• widespread ST depression and T wave flattening/inversion
• prominent U waves
• prolonged QT interval due to U wave (QU interval)

Question 13

What can Hypokalaemia lead to?

Answer 13

• Tachyarrhythmias including SVT, AF and Atrial Flutter
• or Ventricular arrhythmias - VT, VF and Torsades De Pointes