cardiac arrhythmias

Question 1

sinus arrhythmia

Answer 1

normal in children, cyclical change in heart rate with respiration. there is acceleration during inspiration and slowing on expiration

Question 2

superventricular tachycardia

Answer 2

rapid heart rate: 250-300

due to poor cardiac output and pulmonary oedema

Question 3

presentation of supraventricular tachycardia

Answer 3

symptoms of heart failure
hydrops fetalis and intrauterine death
there is reentrant tachycardia due to a circuit of conduction is set up with premature activation of the atrium

Question 4

investigations of supraventricular tachycardia

Answer 4

ECG:

• shows narrow complex tachycardia of 250-300 bpm
• QRS followed by possible P wave
• if heart failure is severe there may be signs of ischaemia, therefore T wave inversion may be present
• when sinus rhythm there may be short PR interval

Question 5

management for supraventricular tachycardia

Answer 5

severely ill child: prompt restoration of sinus rhythm

• circulatory and respiratory response
• vagal stimulating manouvres
• IV adenosine- the treatment of choice
• electrical cardioversion with a synchronised DC shock