Case 2

A 72-year-old man with a previous history of ischaemic heart disease (myocardial infarction 8 years previously, followed by coronary artery bypass grafting) and severely impaired LV systolic function had a pacing device implanted 5 years after his surgery following detection of a marked bradycardia. He is a tablet-controlled diabetic. He has not been seen by Cardiology for more than 12 months, but is under regular review in the Pacing Clinic. He does not think his device has ever delivered therapy and understood his last check (2 months before) to be satisfactory.

He has been brought to the ED following an episode of collapse as he was preparing to go to bed. He recalls little of the events but the paramedics were called by his wife. On their arrival he was noted to be “less responsive” and hypotensive at 60/35. The ambulance rhythm strip can be viewed here:

What was his rhythm at the time of the paramedic ECG?

Transfer to the ED was unremarkable. Currently he is alert and orientated, with a blood pressure of 110/60. He is aware of a relatively rapid heart rate, but is otherwise asymptomatic. His current ECG is available here:

What is his rhythm currently? 

Why do the ECGs appear different?

On arrival at the ED he is assessed and CXR is performed. His chest X-ray can be viewed here. Click the image to see a larger version.

What type of device has been implanted?

What is the most likely cause of his initial collapse?

What is the best short-term management strategy?