Understanding Anterior Wall Myocardial Infarction (MI) on ECG

Introduction

Anterior wall myocardial infarction (MI) is a type of heart attack that affects the front part of the heart, specifically the left ventricle. It occurs due to a blockage in the left anterior descending (LAD) artery, which supplies blood to this area. This condition is serious and requires prompt diagnosis and treatment.

ECG Changes in Anterior Wall MI

To diagnose an anterior wall MI, physicians rely on the electrocardiogram (ECG). Specific changes in ECG recordings help to identify the affected heart region:

Key ECG Features

1. ST-segment elevation

   • Found in leads V1-V6 (depending on the extent of infarction).
   • The ST elevation is often convex (curved upwards), indicating acute injury.

2. Reciprocal ST-segment depression

   • Seen in inferior leads (II, III, aVF).
   • This suggests a significant transmural ischemic process.

3. Q waves

   • Develop in leads V1-V4 (suggesting myocardial necrosis if present late in the infarct).
   • Pathological Q waves indicate irreversible myocardial damage.

4. T-wave inversion

   • Typically follows an MI once the acute phase resolves.
   • Suggests resolving ischemia but can also be seen during an evolving infarct.

Differential Diagnosis

While ST elevation in anterior leads suggests an MI, other conditions can mimic it:

• Pericarditis (diffuse ST elevation without reciprocal changes)
• Early repolarization pattern (especially in younger individuals)
• Left ventricular hypertrophy (ST/T changes due to strain patterns)
• Takotsubo cardiomyopathy (stress-induced cardiomyopathy with similar ECG findings)

Management Approach

**Immediate Steps (Acute Phase)

• Activate emergency response to ensure rapid treatment.
• Administer MONA therapy:
  • Morphine (for pain relief)
  • Oxygen (if hypoxic)
  • Nitroglycerin (to relieve ischemia)
  • Aspirin (to prevent clot progression).
• Reperfusion therapy (Primary PCI is preferred, fibrinolysis if unavailable).
• Antiplatelet therapy (e.g., clopidogrel, ticagrelor) and anticoagulation (heparin).

Long-term Management

After initial treatment, long-term strategies include:

• Beta-blockers and ACE inhibitors to reduce heart strain.
• Statins to lower cholesterol and prevent further plaque buildup.
• Lifestyle modifications (diet, exercise, smoking cessation).
• Cardiac rehabilitation for supervised recovery.

Conclusion

Anterior wall MI is a severe condition requiring immediate recognition and treatment. ECG changes in leads V1-V6 are key to diagnosing it, and rapid intervention improves survival and reduces complications.

Source recommendations

1. 2023 ESC Guidelines for the Management of Acute Coronary Syndromes

1. https://academic.oup.com/eurheartj/article/44/38/3720/7243210
2. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Acute-Coronary-Syndromes-ACS-Guidelines
3. https://pubmed.ncbi.nlm.nih.gov/37622654/
4. https://www.acc.org/Latest-in-Cardiology/ten-points-to-remember/2023/08/29/14/01/2023-esc-guidelines-acs-esc-2023
5. https://pubmed.ncbi.nlm.nih.gov/38206306/

2. 2020 AHA Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

1. https://professional.heart.org/en/science-news/2020-aha-guidelines-for-cpr-and-ecc
2. https://cpr.heart.org/en/resuscitation-science/cpr-and-ecc-guidelines
3. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000918
4. https://cpr.heart.org/-/media/cpr-files/cpr-guidelines-files/highlights/hghlghts_2020_ecc_guidelines_english.pdf
5. https://pubmed.ncbi.nlm.nih.gov/33081529/