Ischemic Heart Disease (IHD)—also known as Coronary Artery Disease (CAD)—is a leading cause of death worldwide. Despite medical advances, it often remains undiagnosed until a critical event like a heart attack or sudden cardiac arrest occurs. Understanding the symptoms of IHD is essential not just for healthcare professionals but for everyone, especially those with risk factors such as diabetes, hypertension, or a family history of heart disease.
To simplify the recognition of clinical symptoms, educators use the mnemonic “ISCHEMIA”, which stands for:
- I – Indigestion & Nausea
- S – Sweating and right-sided Headedness
- C – Chest pain or Congestion
- H – Heart rate faster
- E – Edema & abdominal swelling
- M – Mild dizziness
- I – Ischemic cardiac arrest
- A – Angina
This article breaks down each symptom and explains the clinical significance of IHD, offering a comprehensive resource for students, clinicians, and patients.
What Is Ischemic Heart Disease?
Ischemic heart disease occurs when blood flow to the heart muscle is reduced, usually due to coronary artery narrowing or blockage by atherosclerotic plaques. This restriction deprives the myocardium (heart muscle) of adequate oxygen, especially during physical or emotional stress.
Types of Ischemic Heart Disease:
- Stable Angina
- Unstable Angina
- Myocardial Infarction (Heart Attack)
- Silent Ischemia
- Sudden Cardiac Death
The Mnemonic “ISCHEMIA”: Symptom-by-Symptom Breakdown
Each letter in the mnemonic helps recall the broad symptom profile of IHD. Here’s an in-depth look:
I – Indigestion & Nausea
Many patients, especially women and elderly individuals, experience non-classical symptoms like:
- A burning sensation in the chest or upper abdomen
- Bloating, often confused with gas
- Nausea or vomiting
This occurs due to shared nerve pathways between the gastrointestinal tract and the heart (vagal stimulation). In some cases, cardiac ischemia is mistaken for acid reflux or gastritis.
S – Sweating and Right-Sided Headedness (Dizziness)
Profuse sweating (diaphoresis) is a classic sign of a sympathetic overdrive—the body’s response to stress and pain.
Additionally:
- Right-sided weakness or light-headedness may signal reduced cerebral perfusion due to a drop in cardiac output.
- Sweating without exertion in a patient with chest discomfort should always raise red flags for cardiac ischemia.
C – Chest Pain or Congestion
This is the hallmark symptom of IHD.
Typical Presentation:
- Substernal chest pain, often described as squeezing, pressure, or heaviness
- May radiate to left arm, jaw, neck, or back
- Triggered by exercise or emotional stress, relieved by rest or nitrates
Atypical Presentations:
- Women and diabetics may report tightness, discomfort, or just shortness of breath
Chest congestion (a feeling of heaviness or pressure) is often mistaken for respiratory issues, delaying diagnosis.
H – Heart Rate Faster
In response to myocardial hypoxia, the body increases heart rate (tachycardia) to maintain oxygen delivery.
This can present as:
- Palpitations
- Pounding heartbeat
- Shortness of breath during minor exertion
Persistent tachycardia may also signal a compensatory response in heart failure due to ischemia.
E – Edema & Abdominal Swelling
Chronic or severe ischemic heart disease may lead to right-sided heart failure, resulting in:
- Pitting edema in the legs and ankles
- Ascites or abdominal bloating
- Weight gain due to fluid retention
This fluid overload is a key indicator that the heart is failing to pump effectively, particularly in long-standing cases of IHD.
M – Mild Dizziness
Reduced blood flow to the brain can cause symptoms like:
- Dizziness
- Fainting (syncope)
- Unsteadiness, especially in elderly patients
This symptom is particularly concerning if associated with exertion or emotional stress, indicating transient ischemia or arrhythmias.
I – Ischemic Cardiac Arrest
In severe cases, complete occlusion of a coronary artery can lead to:
- Myocardial infarction (MI)
- Lethal arrhythmias like ventricular fibrillation
- Sudden cardiac arrest
Often, this is the first symptom in silent or undiagnosed IHD cases. Rapid intervention with CPR and defibrillation is crucial.
A – Angina
Angina pectoris refers to the chest discomfort arising due to transient myocardial ischemia without infarction.
Types include:
- Stable angina: Predictable, occurs with exertion
- Unstable angina: Occurs at rest, more severe
- Variant (Prinzmetal) angina: Caused by coronary artery spasm
Angina may last from a few minutes to half an hour and often improves with rest or nitrates.
Risk Factors for Ischemic Heart Disease
| Modifiable | Non-Modifiable |
|---|---|
| Hypertension | Age (men >45, women >55) |
| Diabetes mellitus | Male gender |
| Smoking | Family history of heart disease |
| High LDL cholesterol | Genetic disorders |
| Obesity and inactivity | Ethnicity (South Asians at higher risk) |
| Stress and poor sleep | - |
Diagnostic Workup for Suspected IHD
A proper diagnostic approach is crucial for confirming ischemic heart disease.
1. Electrocardiogram (ECG)
- Detects ST segment changes, Q waves, or arrhythmias
2. Troponin Levels
- Elevated in myocardial infarction
- High-sensitivity troponin preferred for early detection
3. Stress Testing
- ECG or imaging done during exercise or pharmacologic stress
4. Echocardiogram
- Assesses wall motion abnormalities
- Evaluates ejection fraction
5. Coronary Angiography
- Gold standard to visualize coronary artery blockages
6. CT Coronary Angiogram (CTCA)
- Non-invasive test for intermediate-risk patients
Management of Ischemic Heart Disease
1. Lifestyle Modifications
- Smoking cessation
- Weight loss and regular exercise
- Heart-healthy diet (DASH or Mediterranean)
- Stress management
2. Medications
| Drug | Function |
|---|---|
| Aspirin | Anti-platelet, prevents clot formation |
| Statins | Reduce cholesterol and stabilize plaques |
| Beta-blockers | Reduce oxygen demand and heart rate |
| Nitrates | Relieve angina by vasodilation |
| ACE inhibitors | Improve long-term survival in heart failure |
| Calcium channel blockers | Used in vasospastic angina |
3. Procedures
- Percutaneous Coronary Intervention (PCI) – Angioplasty and stenting
- Coronary Artery Bypass Grafting (CABG) – For multi-vessel disease
- Implantable Cardioverter Defibrillator (ICD) – In post-MI patients with arrhythmias
Complications of Untreated IHD
| Complication | Description |
|---|---|
| Myocardial infarction | Permanent heart muscle damage |
| Heart failure | Weakened pumping function |
| Arrhythmias | Irregular or fatal heartbeats |
| Cardiogenic shock | Inability to maintain blood pressure |
| Sudden cardiac death | Fatal within minutes |
Early Warning Signs to Never Ignore
Seek medical attention if you experience:
- Chest discomfort or pain with exertion
- Unexplained shortness of breath
- Persistent fatigue
- Swelling in legs or abdomen
- Sudden dizziness or fainting
- Nausea or sweating during rest
Ischemic Heart Disease in Women
Women often present with atypical symptoms, including:
- Fatigue
- Sleep disturbances
- Jaw or back pain
- Shortness of breath without chest pain
This leads to underdiagnosis and delayed treatment, contributing to higher mortality in women post-MI.
Summary Table: “ISCHEMIA” Mnemonic
| Letter | Symptom | Description |
|---|---|---|
| I | Indigestion & Nausea | GI-like symptoms, especially in women |
| S | Sweating & Dizziness | Sympathetic activation, cerebral hypoperfusion |
| C | Chest pain | Classic angina or pressure |
| H | Heart rate faster | Tachycardia due to low oxygen |
| E | Edema & swelling | Right heart failure signs |
| M | Mild dizziness | Transient ischemia or hypotension |
| I | Ischemic arrest | Cardiac arrest due to MI |
| A | Angina | Exertional or variant chest pain |
Frequently Asked Questions (FAQs)
What is the earliest symptom of ischemic heart disease?
Chest discomfort during exertion (angina) or unexplained fatigue in elderly/women is often the first sign.
Can IHD occur without chest pain?
Yes, this is called silent ischemia, more common in diabetics and older adults.
How is IHD different from a heart attack?
IHD is a broad term; a heart attack (myocardial infarction) is a type of acute event due to complete artery blockage.
Is IHD curable?
While not curable, it can be effectively managed with lifestyle changes, medications, and interventions.
How do I prevent IHD?
- Control blood pressure, sugar, cholesterol
- Eat heart-healthy
- Exercise regularly
- Avoid smoking and stress
Final Thoughts
Ischemic Heart Disease is a silent, progressive threat that can culminate in catastrophic events if not detected early. The “ISCHEMIA” mnemonic is a powerful memory aid to recall the early and late symptoms, helping both healthcare providers and the general public to recognize warning signs promptly.
