Acute lateral wall infarction may show a pattern of ST depression from V1-V2 to V4, which represents a mirror image of ST elevation in leads V7, V8, and V9. Therefore, recording leads V7, V8, and V9 is mandatory in this scenario.

Electrocardiographic Criteria

  • ST-segment depression from V1-V2 to V4
  • ST-segment elevation in V7, V8, and V9
  • Prominent R wave in V1 and V2

ECG With ST Depression From V1 to V3

Electrocardiogram showing ST depression from V1 to V3

ST depression from V1 to V4. In patients with chest pain and ST depression in the precordial leads (V1-V4), the posterior chest leads (V7, V8, and V9) must be recorded to unmask ST elevation in these leads, corresponding to lateral wall infarction.

References

  1. Scheffer MK, De Marchi MFN, de Alencar Neto JN, Felicioni SP. Eletrocardiograma de A a Z. São Paulo: Manole, 2024.
  2. Birnbaum Y, Bayés de Luna A, Fiol M, Nikus K, et al. Common pitfalls in the interpretation of electrocardiograms from patients with acute coronary syndromes with narrow QRS: a consensus report. J Electrocardiol. 2012;45(5):463–75.