Examkin

Soru

Zorluk: ZorCardiovascular System

A precise understanding of electrocardiographic lead localization is essential for identifying the specific coronary artery involved in an acute myocardial infarction. Match each presentation of characteristic 12-lead (and extended) ECG findings with the most likely culprit coronary artery and corresponding region of myocardial infarction.

  • ST-segment elevation in leads II, III, and aVF with ST-segment elevation in right-sided lead V4RProximal right coronary artery (RCA) occlusion causing combined inferior and right ventricular infarction
  • ST-segment elevation in leads V1-V4 with Q wave formation and reciprocal changes in inferior leadsProximal left anterior descending (LAD) artery occlusion causing anteroseptal myocardial infarction
  • ST-segment elevation in leads I, aVL, V5, and V6 with reciprocal ST depression in leads III and aVFLeft circumflex (LCx) artery occlusion causing lateral wall myocardial infarction
  • Deep ST-segment depression in leads V1-V3 with tall, broad R waves and prominent upright T wavesOcclusion of a dominant coronary artery (often LCx or RCA) causing isolated posterior myocardial infarction

Cevap

The correct matches associate inferior/V4R elevations with proximal RCA occlusion, V1-V4 elevations with LAD occlusion, lateral elevations with LCx occlusion, and V1-V3 depressions with tall R waves with posterior MI (LCx/RCA).
Each coronary artery supplies a specific anatomical region of the myocardium, which is reflected by specific leads on the 12-lead ECG. The LAD supplies the anterior wall and septum (V1-V4). The LCx supplies the lateral wall (I, aVL, V5, V6). The RCA supplies the inferior wall (II, III, aVF) and the right ventricle (V4R). Posterior wall infarction (supplied by the dominant RCA or LCx) does not have direct leads on a standard 12-lead ECG, so it is identified by reciprocal changes—ST depression, upright T waves, and tall R waves—in the anterior precordial leads (V1-V3).

Adım Adım Çözüm

1
Analyze the first ECG pattern (ST elevation in II, III, aVF, and V4R).
Identified as an inferior and right ventricular infarction.
Leads II, III, and aVF view the inferior wall (supplied by the RCA), and right-sided lead V4R is the most sensitive and specific lead for right ventricular involvement.
2
Evaluate the second ECG pattern (ST elevation in V1-V4).
Recognized as an anteroseptal myocardial infarction.
The anterior precordial leads strictly view the anterior wall and septum, which are supplied by the proximal left anterior descending (LAD) artery.
3
Assess the third ECG pattern (ST elevation in I, aVL, V5, V6).
Classified as a lateral wall myocardial infarction.
The high lateral (I, aVL) and low lateral (V5, V6) leads view the lateral aspect of the left ventricle, typically supplied by the left circumflex (LCx) artery.
4
Examine the fourth ECG pattern (Deep ST depression in V1-V3 with tall R waves).
Interpreted as reciprocal changes of a posterior myocardial infarction.
Because the standard 12-lead ECG lacks direct posterior leads, acute posterior injury is seen as a mirror image (ST depression instead of elevation, tall R wave instead of Q wave) in the anteroseptal leads.

Anahtar Kavram

Electrocardiographic localization of myocardial infarction correlates specific leads to coronary artery territories: inferior (RCA), anterior (LAD), lateral (LCx), and posterior (RCA or LCx).
Bu soruyu puanla

Konular

Cardiovascular System

Bu konudan daha fazla soru