Inferoposterior Infarction

Report:

Sinus tachycardia 108/min

Accelerated junctional rhythm 98/min

SVEB (6th complex, a pseudofusion beat)

Movement artefact

Pacemaker, electronic, 70/min

Failure to sense

Acute infero(postero)lateral infarction

Low voltage in frontal leads

Comment:

The patient was admitted and discharged with chest pain and only minor angiographic CAD but represented 12 days later following VF arrest with recent inferoposterior MI (Fig 6a). She now had a PTCA resulting in stent failure and RCA dissection resulting in cardiogenic shock and death in multi-organ failure (MOF) two days later. Her last echocardiogram showed septal hypokinesia, reduced RV systolic function and infero-postero-lateral akinesia, with LVEF of only 14%.

Sinus tachycardia is seen at either end of the recording and accelerated junctional rhythm in the middle, most clear-cut between the two paced beats. The large artefact in leads 2 and 3 has no counterpart in simultaneous lead 1 and is easily recognised for what it is for that reason alone (there are, of course, others!).

The posterior infarct is no longer visible due to the balancing loss of anterior forces. More of the base of the heart is now infarcting acutely, with ST segment re-elevation in the inferior leads, new elevation in V5 and reciprocal depression in V1-4.

The pacemaker in Fig 6 fails to sense and has little opportunity to pace, but at least also fails to provoke VF by engaging the T waves of this otherwise very unlucky patient.

6a. The admission ECG. Her anteroseptal leads are mirror image of established posterior wall infarction. 7. 67 year old man with chest pain.