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Electrocardiographic Recognition of Unprotected Left Main ST-Segment Elevation Myocardial Infarction: Looking Beyond

Diego H González-Bravo1, José Escabí-Mendoza1

  • 1Cardiovascular Division, Department of Medicine, Veterans Affairs Caribbean Healthcare System, San Juan, Puerto Rico.

JACC. Case Reports
|July 28, 2021
PubMed

Insights

ST-segment elevation in aVR typically indicates left main coronary artery myocardial infarction. However, this report details two cases of STEMI with LM occlusion lacking aVR ST elevation, highlighting other crucial electrocardiographic indicators.

Area of Science:

  • Cardiology
  • Electrocardiography
  • Myocardial Infarction

Background:

  • ST-segment elevation in the aVR lead is a recognized electrocardiographic sign for identifying left main coronary artery (LM) myocardial infarction.
  • Acute myocardial infarction involving the LM coronary artery requires prompt diagnosis and intervention due to its high-risk nature.

Observation:

  • Two cases of ST-segment elevation myocardial infarction (STEMI) involving acute total occlusion of the LM are presented.
  • Neither case exhibited the traditional ST-segment elevation in the aVR lead.

Findings:

  • The absence of ST-segment elevation in aVR does not exclude the diagnosis of unprotected LM STEMI.
  • Alternative electrocardiographic discriminators are crucial for diagnosing LM STEMI when aVR findings are atypical.

Implications:

  • Clinicians should consider a broader range of electrocardiographic findings beyond aVR ST elevation for diagnosing unprotected LM STEMI.
  • This understanding can improve the timely diagnosis and management of high-risk myocardial infarction involving the left main coronary artery.

Keywords:
ATO, acute total occlusionIABP, intra-aortic balloon pumpLAD, left anterior descending coronary arteryLADEV, left axis deviationLAFB, left anterior fascicular blockLM, left main coronary arteryNPV, negative predictive valuePCI, percutaneous coronary interventionPPV, positive predictive valueRBBB, right bundle branch blockSTD, ST-segment depressionSTE, ST-segment elevationSTEMISTEMI, ST-segment elevation myocardial infarctionTIMI, Thrombolysis In Myocardial Infarctionacute myocardial infarctionelectrocardiogramunprotected left main coronary artery

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