ISCHAEMIC HEART DISEASE

(Coronary Heart Disease)

A condition in which there is insufficient blood flow through the coronary arteries of the heart, thus leading to ischaemia and/or infarction.

Cause

  • Deposition of fatty material (cholesterol plaques) and platelet aggregation inside the coronary arteries causing partial or total obstruction of blood flow

Risk factors

  • Hypertension, diabetes mellitus
  • Smoking
  • Obesity, unhealthy diet, physical inactivity
  • Hyperlipidemia
  • Family history of heart disease

Clinical features

  • Acute coronary syndrome (including acute myocardial infarction): prolonged chest pain, which may be localised on the left or central part of the chest, ranging from mild to severe, at times radiating to the left arm, neck and back, and associated with sweating, dyspnoea, vomiting, anxiety,
    low BP, tachycardia
  • Stable angina: tightness in the chest or a sense of oppression worsening on exertion, relieved by rest and lasting only a few minutes
  • Sudden cardiac death: usually due to fatal arrhytmias

Differential diagnosis

  • Indigestion, hiatus hernia, peptic ulcer
  • Pleurisy, pericarditis, pulmonary embolism
  • Dissecting aneurysm

Investigations

  • Cardiac enzymes (CPK, troponin)
  • ECG (at rest and stress ECG)
  • Echocardiogram

Management of acute coronary syndrome

  • Give acetylsalicylic acid 300 mg single dose (to be chewed)

Refer immediately to hospital

  • Glyceryl trinitrate 500 micrograms sublingually Repeat after 5 min if no response
  • Oxygen therapy if SpO2 < 94%
  • Morphine 2.5-5 mg IV if persisting pain
  • Simvastatin 40 mg or atorvastatin 40 mg
  • Enoxaparin 1 mg/kg SC every 12 hours
  • Treat complications accordingly (pulmonary oedema, arrhythmias)

Consider adding:

  • Beta blockers if no contraindications (SBP <90 mmHg, HR <60 bpm) e.g. Atenolol 25-50 mg daily
    • Ensure close observation of the pulse rate and circulatory status
  • ACE inhibitor e.g. enalapril 2.5-10 mg/daily
  • Refer for further management to higher level of care if unstable

When patient is stable, continue with:

  • Acetylsalicylic acid 75 mg once daily,
  • Atorvastatin 40 mg daily
  • Beta blocker (atenolol or carvedilol) and ACE inhibitor if tolerated
  • Emphasize life changes (healthy diet, no smoking, regular exercise, control of other risk factors)

Management of stable angina

  • Aggressive control of risk factors (hypertension, diabetes, smoking, obesity)
  • Acetylsalicylic acid 75-150 mg mg once a day
  • Atorvastatin 40 mg once a day
  • Beta blockers (e.g. atenolol 25-100 mg) if not diabetic
  • Refer to higher level if still uncontrolled

Prevention

  • Low fat, low cholesterol diet
  • Stop smoking
  • Effective control of hypertension and diabetes mellitus
  • Consider treatment with acetylsalicylic acid and statin in patients with multiple risk factors