Aslanger Sign vs. Aslanger Pattern

While both are named after the same person, the Aslanger Pattern and Aslanger Sign describe entirely different phenomena on a 12-lead ECG. One is a critical, life-threatening ischemic event, while the other is a benign mechanical artifact. Here is the breakdown of the underlying pathophysiology, ECG characteristics, and clinical implications for each.

Aslanger Pattern: The OMI Equivalent

(Described by Aslanger et al. in 2020)

The Aslanger Pattern is a true ischemic signature that indicates an acute inferior Occlusion Myocardial Infarction (OMI) occurring in the presence of severe multi-vessel coronary artery disease.Because it lacks contiguous ST-segment elevation (STE) in leads II and aVF, it frequently fails to meet standard STEMI criteria and is dangerously misclassified as an NSTEMI.

Pathophysiology & Vector Math

Patients presenting with this pattern typically have an acute occlusion of the Right Coronary Artery (RCA) or Left Circumflex (LCx), plus critical stenosis in other vessels (often left main or severe 3-vessel disease).

• Inferior MI Vector: Directs inferiorly and to the right.
• Diffuse Subendocardial Ischemia Vector:Directs superiorly and rightward (toward aVR).
• Resultant Vector: The summation shifts the overall vector sharply to the right. It projects strongly toward lead III and aVR, while effectively canceling out the expected STE in leads II and aVF.

Diagnostic Criteria

1. STE isolated to lead III (lacking contiguous STE in II or aVF).
2. ST-segment depression (STD) in any of leads V4–V6, featuring a terminally positive T-wave.
3. The ST segment in V1 is higher than the ST segment in V2.

Clinical Action: These patients have a high rate of cardiogenic shock, larger infarct sizes, and increased mortality. The Aslanger Pattern should trigger emergent cath lab activation for rapid revascularization, bypassing standard NSTEMI medical management.

Aslanger Sign: The Electromechanical Artifact

(Described by Aslanger and Yalin in 2012)

In stark contrast, the Aslanger Sign (also known as the arterial pulse-tapping artifact or electromechanical association artifact) is a completely non-ischemic phenomenon.

Pathophysiology

This artifact occurs when limb electrodes are placed directly over or too close to a pulsatile artery (such as the radial or posterior tibial arteries). The mechanical pulsation of the artery physically taps the electrode. Because the arterial pulse is mechanically tied to cardiac systole, it generates a rhythmic voltage disturbance that is perfectly synchronized with the cardiac cycle.

ECG Characteristics

• It presents as pseudo-repolarization abnormalities, commonly mimicking TP segment downsloping/upsloping, ST-segment shifts, or prominent U-waves.
• The distortion is usually observed in multiple limb leads but classically spares one (typically the lead acting as the reference point for the exploring electrode).
• It is more common in hyperdynamic states where the arterial pulse is bounding.

Clinical Action: The artifact resolves immediately by moving the limb electrodes away from the arterial pulse points (e.g., placing them higher on the forearms or calves) and repeating the ECG.

Summary Comparison

	Aslanger Pattern	Aslanger Sign
Origin	True cardiac ischemia (Acute OMI)	Mechanical artifact (Arterial pulsation)
Underlying Pathology	Inferior occlusion + severe multi-vessel CAD	None (Electrode placement error)
Key ECG Finding	Isolated STE in III, STD in V4-V6	Distorted TP/ST segments time-locked to systole
Clinical Next Step	Emergent angiography / Reperfusion	Reposition limb electrodes and repeat ECG

References

Aslanger, E., Yıldırımtürk, Ö., Şimşek, B., et al. (2020). A new electrocardiographic pattern indicating inferior myocardial infarction. Journal of Electrocardiology, 61, 41–46. https://doi.org/10.1016/j.jelectrocard.2020.04.008

Aslanger, E., & Yalin, K. (2012). Electromechanical association: a subtle electrocardiogram artifact. Journal of Electrocardiology, 45, 15–17. https://doi.org/10.1016/j.jelectrocard.2010.12.162