ECG Topic - Aslanger Pattern

✏️

10/27/24, by Eric Tang MD. Reviewed by Esteban Davila MD.

Last updated 10/27/24

Introduction

Aslanger pattern is an ECG finding that may indicate an acute occlusive inferior MI w/ concurrent multi-vessel disease that does not display classic contiguous STE elevation seen in traditional STEMI Criteria. Instead, it presents with:

STE in III but not in other inferior leads (II and aVF).
STD in leads V4 to V6 (not V2) with a positive or at least terminally positive T wave
A higher ST-segment in lead V1 than in lead V2.

From Aslanger et al (2020)

The Paper

Aslanger E, Yıldırımtürk Ö, Şimşek B, et al. A new electrocardiographic pattern indicating inferior myocardial infarction. J Electrocardiol. 2020;61:41-46. doi:10.1016/j.jelectrocard.2020.04.008. L

Aslanger et al (2020) studied 1000 NSTEMI, 1000 control (no MI) and about 400 inferior STEMI patients during the same time period. They found that 6.3% of patients classified as NSTEMI exhibited this pattern. These patients often had multi-vessel coronary disease, a higher risk of mortality, and a larger infarct size than typical NSTEMI patients.

Key Results

In-hospital mortality was similar between patients with the Aslanger pattern and those with inferior STEMI (5% vs. 4%), but much higher than in NSTEMI patients (1%).
One-year mortality was higher in Aslanger pattern patients (11%) compared to NSTEMI (3%), closely matching inferior STEMI patients (8%)
The most commonly involved artery in these patients was the left circumflex (as opposed to RCA), often associated with multi-vessel disease.
In the Aslanger pattern / NSTEMI group, 25% of patients had an acute coronary occlusion, 25% had chronic total occlusion and 92% had a “culprit” lesion.

Limitations

Retrospective, single center design
Lack of universal definition of acute coronary occlusion
Aslanger pattern may be caused by alternative diagnoses:

Chronic change from previous ischemic insult (0.5% of patients in the control, or no MI, group had Aslanger pattern).
Acute inferior MI in the presence of previous infarctions
Isolated basal inferoseptal infarction

Why does only 1 inferior lead have STE?

This finding arises from the summation of two vectors:

ST-vector from transmural ischemia of an inferior MI (directed inferiorly)
ST-vector caused by subendocardial ischemia (STD) from concurrent coronary disease (directed upward & away from lead II and aVF and towards AVR. Remember the net vector of subendocardial ischemia is the opposite direction of the leads with STD.

From LITFL Aslanger Pattern

The result is a dominant rightward vector projecting toward lead III but perpendicular to or away from the other inferior leads, thus explaining the absence of STE in leads II and aVF. In other words - in diffuse subendocardial ischemia in multi-vessel CAD there is AVR STE with diffuse depressions (left) In inferior STEMI, there are STE in II, II, avF (right). The depressions and elevations cancel out and the net vector results in an isolated STE in lead III.

Why this matters?

Time is myocardium. When combined with a concerning history and physical exam, this pattern should be treated with the same urgency as an occlusive MI as it can signify an acute coronary event that requires emergent reperfusion.