Myocardial infarction (MI)

Photo: Dr. Reena's

What is myocardial infarction

Myocardial infarction, also known as a heart attack, occurs when blood flow decreases or stops to a part of the heart, causing damage to the herat muscle. The most common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck or jaw.

Clinical features of myocardial infarction

1. Chest pain,

2. Pain or discomfort in the jaw, neck and back.

3. Pain or discomfort in the arm and shoulder.

4. Cold sweating.

5. Weakness.

6.  Light headedness.

7.  Dyspnea.

8. Orthopnea.

9. Syncope.

10. Anxiety.

Risk factors for myocardial infarction

1. Hypertension.

2. Diabetes.

3. Smoking.

4. Dyslipidemias.

5. Obesity.

6. Family history.

7. Physical inactivity.

8. Age.

9. Excessive alcohol consumption.

Diagnosis criteria of myocardial infarction

Required presence of atleast two of the following characteristics:

1. Typical heart attack symptoms.

2. Characteristic rise and fall pattern of cardiac marker in plasma.

3. Rise and gradual fall of cardiac toponins.

4. More rapid rise and fall of  CK-MB.

5. Typical ECG pattern.

Evaluation of MI

1. ECG.

2. Ecocardiography.

3. Cardiac enzymes.

4. Serum electrolytes.

5. Lipid profile.

Treatment of myocardial infarction (MI)

1. Anti-platlet agents: Asprin 162 mg or 325 mg orally.

2. Analgesics: Morphine IV 10 mg or Pethidine 50-75 mg for relief of pain.

3. Nitrates: Nitroglycerin.

4. Reperfusion therapy

                                        *  Primary percutaneous intervention (PCI).

                                         * Thrombolytic therapy i.e. Sterptokinase, Altiplase.

5. Low flow oxygen therapy: 2-4 litre per minute.

6. Coronary artery bypass grafting: