Cardiac Syndrome X (Microvascular Angina)
💡 About Syndrome X (Cardiology)
- A recognised cause of angina-like chest pain despite normal coronary arteries on angiography.
- Also called Cardiac Syndrome X or Microvascular Angina.
- Prognosis is usually very good 👍, with low risk of major adverse cardiac events, though symptoms may persist.
⚙️ Aetiology & Pathophysiology
- Thought to involve microvascular dysfunction – impaired dilation of small coronary arterioles reduces myocardial perfusion.
- More common in middle-aged, postmenopausal females.
- May be influenced by oestrogen deficiency, endothelial dysfunction, autonomic imbalance.
🩺 Clinical Features
- Recurrent angina-like chest pain, often exertional but may also occur at rest.
- Pain may last longer than in typical angina and be less responsive to nitrates.
- Symptoms can impact quality of life but do not usually indicate high mortality risk.
🔍 Differentials
- Classic ischaemic heart disease (IHD) due to atherosclerosis.
- Oesophageal spasm, anxiety/panic disorders, musculoskeletal chest pain.
🧪 Investigations
- ECG (exercise stress test): ST depression may be seen.
- Troponin: Normal (no myocardial necrosis).
- Echocardiogram: Usually normal.
- Coronary angiography: Normal large epicardial arteries.
- Stress Echo / Myocardial perfusion imaging (Thallium): Often normal or inconclusive.
💊 Management
- ⚕️ Conventional anti-anginals (beta-blockers, calcium channel blockers, nitrates) – may help some patients.
- 💊 Newer agents: nicorandil, ivabradine, ranolazine can be useful for resistant symptoms.
- 👩🦱 Hormone Replacement Therapy (HRT) – may improve symptoms in postmenopausal women, especially if associated with vasomotor symptoms (e.g. hot flushes).
- 🧠 Pain modulation therapy: low-dose imipramine (tricyclic antidepressant) reduces central pain perception.
- 🌀 Cognitive Behavioural Therapy (CBT) & Hypnotherapy: can help reframe pain perception and reduce symptom burden.
- 🏃 Lifestyle optimisation: exercise, weight control, smoking cessation, stress management all improve vascular function.
📚 References
✨ Teaching Pearl: Cardiac Syndrome X reminds us that “normal coronary angiography does not always equal a benign diagnosis.”
Microvascular dysfunction is increasingly recognised in women and requires a holistic, symptom-focused approach.
