Electrocardiographic Abnormalities and Cardiac Disorders

Myocardial Infarction: ECG Changes, Diagnostic Criteria, and Management

Myocardial infarction (MI), commonly known as a heart attack, is a medical emergency requiring timely intervention. Electrocardiographic (ECG) changes play a critical role in its diagnosis, helping clinicians differentiate between various types of infarctions.

ECG Changes in Myocardial Infarction

• ST-Elevation MI (STEMI): Characterized by ST-segment elevation in contiguous leads, indicative of complete coronary artery occlusion.
• Non-ST-Elevation MI (NSTEMI): ST depression and T wave inversions without ST elevation, often due to partial coronary blockage.
• Other Abnormalities: Presence of pathological Q waves, loss of R wave progression, and hyperacute T waves.

Diagnostic Criteria

MI diagnosis involves a combination of clinical symptoms, ECG findings, and biomarker analysis. The universal criteria include:

• Elevated cardiac troponin levels.
• Acute chest pain lasting more than 20 minutes.
• ECG changes such as ST elevation, new-onset left bundle branch block (LBBB), or Q waves.

Acute Management

Immediate medical interventions include:

• Oxygen Therapy: Administered if oxygen saturation is below 90%.
• Antiplatelet Therapy: Aspirin and P2Y12 inhibitors (e.g., clopidogrel).
• Reperfusion Strategies: Primary percutaneous coronary intervention (PCI) or thrombolysis.
• Beta-blockers: Used for reducing myocardial oxygen demand.

Long-Term Care and Prevention

Post-MI management focuses on secondary prevention through lifestyle modifications and medication adherence.

• Medications: Statins, beta-blockers, ACE inhibitors, and anticoagulants.
• Cardiac Rehabilitation: Supervised exercise and dietary changes.
• Risk Factor Modification: Controlling hypertension, diabetes, and smoking cessation.

Conclusion

Recognizing ECG abnormalities in myocardial infarction is crucial for timely intervention. Advances in cardiac diagnostics and management continue to improve survival rates and quality of life for affected individuals.