Report:

Sinus tachycardia 124/min

2:1 AV block

A-sensing ventricular pacemaker rhythm 62/min

Fusion beats

Acute or recent inferolateral infarction

Comment:

My first thought was something exotic: accrochage between the temporary pacemaker and the sinus tachycardia, halved by AVB. I had never seen such accrochage. I had never seen a dual pacemaker used for acute infarction in our CCU, either. Well, this was one and a permanent implant at that. The patient sustained a large infarct and died a few weeks later. The DDD unit seemed to his Cardiologist simpler and more reliable to provide hæmodynamic support during the critical initial period.

The pacing AV interval must have been extended beyond the native conducted PR interval of 0.22” to allow P waves to activate the atria.

The LAD is not reported, being due to combination of inferior infarction and the pacemeker. We can be sure there is no LAHB as well, given the secondary R waves in the inferior leads and their absence in aVR.

Below (fig 127a) is a trace taken two days later (the AV interval shortened), in sinus tachycardia, in 1:1 conduction.

Fig 127a. There is less fusion, more paced morphology. Ideally, the pacemaker should have been turned off or reduced to standby functions at this stage. Fat complexes perform less well than lean ones.

Fig 128. 81 year old lady in ICU with biliary pancreatitis and tendency to bradycardia and hypotension. Atrial and ventricular leads were inserted and connected to an external dual pacing unit.

Fig 128a.