ST Elevation or Non-Q Infarction?

Report:

Sinus rhythm 87/min

ST/T changes c/w infarction/ischæmia

Comment:

This type of tracing is difficult to define. ST segment elevation infarction requires, by definition10, 1 mm elevation in at least two contiguous leads sustained over 30 minutes. Here the elevation in confined to V1 (aVR not counting), with no known time frame and (possibly reciprocal) ST depression in multiple leads. Or, aVR counting, the contiguity is only a paper, rather than electrical, contiguity. The overall appearances are similar to main left coronary artery stenosis in presentations of acute ischæmia; this patient, with history of remote CABGs for triple vessel disease, may well have had a “main left” equivalent.

The ECG became almost normal over 5 hours (Fig 12a), but the cardiac injury markers were quite elevated: an infarction had occurred. The VEBs in V1 knew it11 (Fig 12b). In fact, lead V1 in the original trace also knew it: its ST elevation, shared by the neighbouring leads or not, certainly “looks” infarctional: it has that upward bulge into the T wave. Like pornography – one knows it when one sees it, but it eludes definition.

The foregoing supports the term non-Q infarction as the best descriptor of what actually happened. But we know what happened only through high troponin and CPK values: the acute episode could equally have been ischæmia rather than infarction.