Atrial flutter + atrial myoxma + heart block

Question 1

What is atrial flutter?

Answer 1

Atrial flutter is a form of supraventricular tachycardia characterised by a succession of rapid atrial depolarisation waves.

Question 2

What ECG findings are there in atrial flutter?

Answer 2

1. ‘Sawtooth’ appearance
2. As the underlying atrial rate is often around 300/min the ventricular or heart rate is dependent on the degree of AV block. For example if there is 2:1 block the ventricular rate will be 150/min
3. Flutter waves may be visible following carotid sinus massage or adenosine

Question 3

What is the management of atrial flutter?

Answer 3

1. Similar to that of atrial fibrillation although medication may be less effective
2. Atrial flutter is more sensitive to cardioversion however so lower energy levels may be used
3. Radiofrequency ablation of the tricuspid valve isthmus is curative for most patients

Question 4

What is atrial myxoma?

Answer 4

• Atrial myxoma is the most common primary cardiac tumour
• 75% occur in left atrium, most commonly attached to the fossa ovalis
• more common in females

Question 5

What are the features of atrial myxoma?

Answer 5

1. Systemic: dyspnoea, fatigue, weight loss, pyrexia of unknown origin, clubbing
2. Emboli
3. Atrial fibrillation
4. Mid-diastolic murmur, ‘tumour plop’
5. Echo: pedunculated heterogeneous mass typically attached to the fossa ovalis region of the interatrial septum

Question 6

What are atrial septal defects?

Answer 6

• Atrial septal defects (ASDs) are most likely congenital heart defect to be found in adulthood
• Significant mortality, with 50% of patients being dead at 50 years.
• Two types of ASDs are recognised:
  
  • ostium secundum (most common)
  • ostium primum

Question 7

What are the features of ASDs?

Answer 7

Features

• ejection systolic murmur, fixed splitting of S2
• embolism may pass from venous system to left side of heart causing a stroke

Ostium secundum (70% of ASDs)

• associated with Holt-Oram syndrome (tri-phalangeal thumbs)
• ECG: RBBB with RAD

Ostium primum

• present earlier than ostium secundum defects
• associated with abnormal AV valves
• ECG: RBBB with LAD + prolonged PR interval

Question 8

What is first-degree heart block?

Answer 8

• PR interval > 0.2 seconds
• asymptomatic first-degree heart block is relatively common and does not need treatment

Question 9

What is second-degree heart block?

Answer 9

• type 1 (Mobitz I, Wenckebach): progressive prolongation of the PR interval until a dropped beat occurs
• type 2 (Mobitz II): PR interval is constant but the P wave is often not followed by a QRS complex

Question 10

What is third-degree heart block?

Answer 10

No association between the P waves and QRS complexes