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Ischemic Heart Disease: Symptoms, Causes and Treatment
What is Ischemic Heart Disease?
Ischemic heart disease (IHD), or coronary artery disease (CAD), occurs when blood flow to the heart muscle is restricted due to the narrowing or blockage of the coronary arteries. This is typically caused by atherosclerosis—a build-up of fatty plaques in the artery walls. The reduced blood supply deprives the heart muscle of oxygen, which could subsequently lead to angina, myocardial infarction (heart attack) or heart failure. In some cases, the obstruction may be in the smaller vessels (microvascular disease) or may be due to coronary artery spasm.
How Common is Ischemic Heart Disease?
IHD remains the leading cause of death worldwide [1].
In Singapore, the Singapore Myocardial Infarction Registry (SMIR) noted a rise in acute myocardial infarction (AMI) cases from 7,344 in 2010 to 11,631 in 2020. The age-standardised incidence rate (ASIR) also rose from 194.5 to 207.0 per 100,000 population in that decade.
Symptoms
The hallmark symptom is angina pectoris—a type of chest discomfort. Patients may describe:
- Pressure or tightness behind the breastbone
- Radiating pain to the jaw, neck or left arm
- Shortness of breath, nausea or cold sweat
Types of Angina
- Stable Angina: Triggered by physical or emotional stress, relieved by rest.
- Unstable Angina: Occurs at rest, and is more intense and unpredictable; may indicate an imminent heart attack.
Silent Ischemia
Some individuals, particularly diabetics, may experience no symptoms. This condition, known as silent ischemia, is detected through diagnostic tests rather than patient complaints.
When to See a Doctor?
Immediate consultation is warranted if the chest pain:
- Persists beyond a few minutes
- Occurs while the individual is at rest
- Comes with dizziness, nausea, palpitations, cold sweat or fainting
Call emergency services (995 in Singapore) if a heart attack is suspected.
Cause
Ischemic heart disease arises when the heart muscle does not get enough oxygen because of the reduced or blocked blood supply through the coronary arteries. This lack of oxygen is primarily due to structural or functional disturbances within the arteries. The main causes include:
Coronary Artery Disease (Atherosclerosis)
This is the most common and well-established cause of ischaemic heart disease.
- Cause: Over time, fatty substances like cholesterol build up inside the heart’s arteries. This build-up is called plaque.
- How it happens: Plaque sticks to the artery walls, making them narrower and harder. This limits the amount of blood and oxygen that could reach the heart, especially when the heart is working harder—when the person is involved in exercise or is experiencing stress.
- Why it matters: When the heart doesn’t get enough oxygen, it can cause chest pain (angina). If the blockage gets worse or cuts off blood flow completely, a heart attack might occur. This type of damage builds slowly over the years, often without symptoms.
Blood Clot
- Cause: Sometimes, the plaque in an artery could break open. When that happens, the body will treat it like an injury and form a blood clot.
- How it happens: The clot could quickly block the artery, stopping blood from reaching the heart muscle. This blockage could happen suddenly and without warning.
- Why it matters: This causes a heart attack. Without immediate treatment, part of the heart muscle could dissipate, leading to permanent damage or even death. Clots are a major cause of sudden heart attacks.
Coronary Artery Spasm
- Cause: The heart’s arteries could sometimes tighten suddenly (spasm), even if there is no major blockage. This could be triggered by stress, smoking, cold air or drugs like cocaine.
- How it happens: The muscle in the artery wall squeezes too tightly, making the artery narrower for a short time. This reduces blood flow to the heart.
- Why it matters: This could cause sudden chest pain, often while the individual is at rest or early in the morning. If the spasm lasts too long, it could cause a heart attack. Even short spasms, if they happen often, could damage the heart over time.
Risk Factors
Non-Modifiable
- Age: Risk increases after 35 years old
- Gender: Higher in men
- Ethnicity: Higher in Indians and Malays
- Family History: CAD before age 55 in men or 65 in women
Modifiable
- High Blood Pressure: Damages the arterial walls
- High Blood Cholesterol: Promotes plaque growth
- Diabetes Mellitus: Speeds up atherosclerosis
- Smoking: Induces vascular inflammation and clots
- Obesity/Overweight: Doubles the risk of IHD
- Physical Inactivity: Reduces cardiovascular resilience
- Unhealthy Diet: Includes food high in saturated fat, low in fibre
Other factors comprise chronic kidney disease, non-alcoholic fatty liver disease and autoimmune conditions.
How is Ischemic Cardiomyopathy Diagnosed?
Ischemic cardiomyopathy refers to heart muscle weakness caused by chronic blood supply deficiency. Symptoms mirror heart failure:
- Fatigue
- Breathlessness
- Swelling in the legs or abdomen
Diagnostic tools include:
- Blood tests for cardiac markers
- Electrocardiogram (ECG)
- Echocardiography
- Stress tests
- Cardiac MRI
- Coronary angiography
How is Ischemic Heart Disease Treated?
Lifestyle Changes
Cornerstone of long-term management:
- Diet: Emphasise whole-grains, fruit, vegetables and omega-3 fats
- Exercise: Focus on 150 – 300 minutes of moderate-intensity aerobic physical activity and strengthening exercise twice a week
- Smoking Cessation
- Weight Management
- Alcohol Moderation
Medication
- Beta Blockers: Reduce workload on the heart
- ACE Inhibitors/ARBs: Improve heart function
- Statins: Lower LDL cholesterol
- Antiplatelets: Prevent clot formation
- Anticoagulants: Used in patients with abnormal heart rhythm
Procedures and Surgery
- Percutaneous Coronary Intervention (PCI): Balloon angioplasty with stenting
- Coronary Artery Bypass Graft (CABG): Use of graft vessels to bypass blocked arteries
What is the Prognosis for People with Ischemic Heart Disease?
Prognosis depends on:
- Severity and extent of arterial blockage
- Heart function
- Timeliness and type of intervention (PCI or CABG)
- Adherence to lifestyle changes and medication
- Social support and access to care
With proper management, many patients will have meaningful and active lives.
How to Reduce Your Risk of Developing Ischemic Cardiomyopathy?
- Adopt a heart-healthy diet
- Maintain regular physical activity
- Quit smoking / vaping
- Control blood pressure, blood sugar and blood cholesterol
- Limit alcohol
- Attend regular health screenings
How to Manage Ischemia?
- Follow treatment plans diligently
- Monitor symptoms and report changes
- Avoid triggers like emotional stress or extreme exertion
- Sustain a healthy lifestyle
- Use medications as prescribed
Conclusion
Ischemic heart disease is a manageable condition when it is identified early and is addressed through a comprehensive strategy—lifestyle changes, medications and when needed, interventions. Prevention remains the most effective long-term measure. Managing risk factors and regular follow-up are key to long-term cardiovascular health.
Article is contributed by Prof Tan Huay Cheem of the Chairman of the Singapore Heart Foundation and Senior Consultant at the National University Heart Centre, Singapore.
References
- Wang, Y., Li, Q., Bi, L., Wang, B., Lv, T., & Zhang, P. (2025). Global trends in the burden of ischemic heart disease based on the global burden of disease study 2021: The role of metabolic risk factors. BMC Public Health. https://doi.org/10.1186/s12889-025-21588-9
- (n.d.). Myocardial Ischemia. Mayo Clinic. Retrieved July 18, 2025, from https://www.mayoclinic.org/diseases-conditions/myocardial-ischemia/symptoms-causes/syc-20375417
- (n.d.). Coronary Artery Disease. Cleveland Clinic. Retrieved July 18, 2025, from https://my.clevelandclinic.org/health/diseases/16898-coronary-artery-disease
- (n.d.). Ischemic Heart Disease. Clinic Barcelona. Retrieved July 18, 2025, from https://www.clinicbarcelona.org/en/assistance/diseases/ischemic-heart-disease
