Written Practice Questions & Answer(MRCP Part 2 )

A 66-year-old male presents one month after insertion of a dual chamber pacemaker for complete heart block for review in cardiology clinic. He says that his previous symptoms of shortness of breath, lethargy and peripheral oedema have improved but he has developed occasional symptoms of palpitations which seem to come and go sporadically.

On examination, chest is clear, heart sounds are normal, heart rate is 72/min regular, blood pressure 95/60mmH., No added heart sounds, apyrexial, GCS 15.

His ECG shows an otherwise normal ECG apart from an apparent mismatch between the QRS complex and pacing-sensing and capture.

What is the most likely diagnosis?

Anxiety related palpitations
Atrial lead displacement
Pacemaker syndrome.
Paroxysmal AF
Ventricular lead displacement

acemaker complications can be a common problem in the period following insertion and can be divided into early complications (<6 weeks) or late (>6 weeks). Lead dislodgement can occur following trauma or sporadically and can be either atrial or ventricular.

Atrial dislodgment affects up to 3% of people whereas ventricular is less common affecting 1%. The ECG showing loss of sensing and capture around the QRS complex, in this case, describes ventricular lead displacement in a dual chamber pacemaker.

Atrial lead displacement would show an ECG with loss of atrial sensing and capture.

Pacemaker syndrome would show AV dyssynchronisation. Paroxysmal atrial fibrillation (AF) is plausible in this scenario given the sporadic nature but not likely