Old myocardial infarction

Disease Description (Causes and Symptoms)

• Definition and pathophysiology: When the coronary arteries become narrowed (stenosis) due to atherosclerosis (arteriosclerosis), or when a thrombus forms and acutely occludes a coronary artery, the affected myocardium undergoes necrosis. The necrotic area becomes fibrotic and leaves a scar (chronic/old myocardial infarction), resulting in localized decreased myocardial contractility and structural remodeling of the heart.
• Major causes (risk factors): Hyperlipidemia, smoking, diabetes mellitus, hypertension, abdominal obesity, physical inactivity, psychological stress, etc.
• Major symptoms:
  • At the time of the previous myocardial infarction: Chest pain or pressure lasting more than 30 minutes, cold sweats, shortness of breath, and pain radiating from the chest to the jaw, neck, and left arm (mainly the left side).
  • Clinical findings of old myocardial infarction: There may be no chest pain (silent MI), followed by arrhythmia (abnormal heart rate), shortness of breath with physical activity, fatigue, symptoms of congestive heart failure (edema and weight gain), and worsening of pre-existing chest pain. Tests may show Q waves, localized wall-motion abnormalities, and findings of fibrosis.
• Risk of complications: Chronic heart failure, ventricular arrhythmias and sudden cardiac death, left ventricular aneurysm, left ventricular wall thrombus and embolism, and functional mitral regurgitation, etc.

Treatment Methods

• Goals: Manage symptoms after myocardial damage, preserve or restore cardiac function when possible, prevent complications, and reduce the risk of recurrence (additional ischemia or reinfarction) and death.
• Drug treatment (focused on secondary prevention)
  • Antiplatelet agents: Aspirin (long-term basic therapy); a P2Y12 inhibitor (such as clopidogrel or ticagrelor) may be used in combination when necessary, depending on the history of procedures or the physician’s judgment.
  • Statins: High-intensity statins (to reduce the risk of recurrent cardiovascular events).
  • Beta-blockers: Reduce myocardial oxygen demand and the risk of arrhythmia and death (particularly important in patients with reduced left ventricular function).
  • ACE inhibitors/ARBs: Inhibit left ventricular remodeling and reduce heart failure and mortality (for those with reduced contractility or at risk of heart failure).
  • Aldosterone antagonists: Indicated when heart failure or reduced left ventricular function with symptoms is present.
  • Anticoagulation (example): Considered when a left ventricular thrombus is present or in specific situations.
• Procedures/Surgery
  • Percutaneous coronary intervention (PCI): Revascularization or restoration of blood flow when needed for a treatable coronary lesion.
  • Coronary artery bypass grafting (CABG): Recommended for multivessel disease, left main coronary artery disease, or specific coronary anatomical conditions.
  • Device therapy: An implantable cardioverter-defibrillator (ICD) may be considered in cases of significant ventricular dysfunction (LVEF ≤ the relevant threshold) and risk of recurrent life-threatening arrhythmia.
• Rehabilitation and lifestyle management
  • Cardiac rehabilitation program (exercise prescription, education, and risk-factor management).
  • Smoking cessation, weight control, regular exercise (at an intensity directed by a physician), a low-salt and low-saturated-fat diet, and management of blood pressure, blood glucose, and lipid targets.
  • Vaccination against infections (e.g., influenza) is recommended to prevent cardiovascular complications.
• Monitoring and follow-up tests
  • Echocardiography to assess left ventricular contractility (LVEF) and regional wall motion.
  • Electrocardiography (at baseline and when symptoms occur); if necessary, Holter monitoring, stress testing, nuclear medicine testing, and cardiac MRI (assessment of fibrosis and viability).
  • Regular blood tests (lipids, blood glucose, kidney function, etc.).
• Precautions (related to treatment)
  • Do not stop or change medications on your own (due to risks such as bleeding and reinfarction).
  • Manage the risk of bleeding when using anticoagulants or antiplatelet agents (situations that should be reported to a medical institution).
  • Immediate emergency evaluation is necessary if new chest pain, fainting, acute shortness of breath, edema, or similar symptoms occur.

Checklist Before an Outpatient Visit (Including Items to Bring and Example Questions)

• Items to bring (for an outpatient visit)
  • A list of current medications (including doses and times of administration) and prescriptions/medicine bags
  • Previous test results (electrocardiograms, echocardiograms, coronary angiography [procedure records], blood test results, etc.) or copies of test records
  • A symptom diary (the timing, duration, and triggering circumstances of recent shortness of breath, chest pain, fainting, or dizziness)
  • Records of weight, blood pressure, and heart rate measurements (if available)
  • Information related to lifestyle habits (smoking, exercise, and diet)
• Information that is useful to provide to the doctor during the outpatient visit
  • Changes in symptoms (new chest pain, whether symptoms occur at rest, and the degree of limitation during activity)
  • History of hospitalization or procedures (dates of PCI/CABG and hospital names)
  • Abnormal findings on recent tests (Q waves on the electrocardiogram, LVEF values, etc.)
• Example questions before an outpatient visit (to prepare yourself)
  • Which of my current medications should I continue taking, and which should I stop taking?
  • When will the next tests (echocardiography, stress testing, blood tests, etc.) be needed?

General Example Questions to Ask the Doctor

• What are the major side effects and precautions for this medication (or combination of medications)?
• What is my left ventricular contractility (LVEF)? What does it mean for my prognosis?
• Which lifestyle habits should I change first to reduce the risk of recurrence (another myocardial infarction)?
• Up to what intensity and in what forms can I exercise safely? Is a rehabilitation program necessary?

Examples of Disease-Specific Questions

• In my case, based on the test results, is ICD implantation or another type of device therapy recommended? What criteria did you apply?
• What tests are needed to assess the viability of localized myocardium affected by my previous myocardial infarction (e.g., cardiac MRI or nuclear medicine testing), and how likely is it that revascularization or reconstructive surgery would be beneficial?

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Note: The above content is general medical information, and its application varies depending on the individual’s condition. Please consult your attending physician to determine a specific diagnosis and treatment plan.