The ECG shown on page 13 (Figure 3) is that of a 76-year-old male presenting with acute appendicitis requiring surgery. He is haemodynamically stable.

a) Comment on this ECG. (20% marks)

The anaesthetist would like a temporary pacing wire placed before surgery.

b) What is your advice? (20% marks)

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College answer

a)    Secondary degree AV block, Mobitz type 1 
 
b)    Patients with Mobitz type 1 block who are asymptomatic and haemodynamically stable do not require a pacing wire. If unstable then atropine could be tried. Transcutaneous or transvenous pacing is then indicated. Reversible causes like myocardial ischaemia, high vagal tone or drugs (beta blockers, Ca channel blockers or digoxin) should be sought and corrected.  

Additional Examiners' Comments: 
There were a number of common difficulties candidates encountered. The main one was lack of knowledge in this area, and the main gap was in recognising the second-degree AV block – type 1.  Many of the answers were 'scattergrams' of all the ECG patterns/phrases the candidates could remember – sometimes contradictory! Another systemic problem seemed to be time allocation. A number of candidates missed whole parts of the question or answered part 3 with less care and attention than parts 1 and 2. 

 

Discussion

Image stolen from the LITFL page on this heart block

References

2012 ACCF/AHA/HRS Focused Update of the 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines