الذبحة الصدرية المستقرة

Definition

Stable angina is predictable chest pain brought on by effort or emotion, because a narrowed coronary artery cannot deliver enough blood when the heart’s oxygen demand rises.

Mechanism

• A fixed fatty plaque narrows the artery
• At rest supply is enough; with effort there is a mismatch between demand and supply

Symptoms

• Pressure, heaviness or burning behind the sternum, sometimes spreading to the arm or jaw
• Starts with effort and settles within minutes with rest or nitroglycerin

Diagnosis

ECG (often normal between attacks), exercise testing, and sometimes CT coronary angiography or catheterisation.

Treatment

• Attack: sublingual nitroglycerin
• Symptom prevention: beta-blockers, calcium channel blockers or long-acting nitrates
• Heart protection: aspirin and a statin, with BP, glucose and smoking control
• PCI or bypass surgery depending on the anatomy

Nursing care

• Teach nitroglycerin use: one tablet under the tongue, repeated every 5 minutes up to 3 times
• Sit down before taking it because it can cause dizziness
• Keep it in its original dark container away from heat

Exam point

If the pain has not improved 5 minutes after the first tablet, the client calls an ambulance, because it may be an MI rather than stable angina.