Ischemic Heart Disease (IHD) is a condition that occurs when the heart muscle does not receive an adequate supply of oxygen-rich blood. This shortage, known as ischemia, is caused by narrowed heart arteries. The resulting imbalance between the heart’s oxygen demand and the available supply can lead to damage to the heart muscle.
Causes and Risk Factors of IHD
The most frequent cause of IHD is atherosclerosis, a process involving the gradual buildup of deposits called plaques within the coronary arteries. These plaques are composed of substances like fat, cholesterol, and calcium, which can harden over time, causing the arteries to narrow and restricting blood flow. This process can begin as early as childhood and progress slowly over many years.
A person’s likelihood of developing IHD is influenced by manageable and non-manageable factors. Modifiable risk factors include high blood pressure, which accelerates damage to the coronary arteries, and high levels of “bad” (LDL) cholesterol, which contributes to plaque formation. Tobacco use is also damaging, as chemicals in smoke harm blood cells and the structure of blood vessels.
Other modifiable risks include diabetes, which can damage blood vessels over time. Being overweight or obese is a major contributor, as it is linked to high blood pressure, high cholesterol, and diabetes. A sedentary lifestyle and a diet high in saturated fats and sodium also compound these risks.
Non-modifiable risk factors are those that cannot be changed. Advancing age is a primary risk factor, as the chances of developing atherosclerosis increase over a lifetime. Men have a higher risk than women, though a woman’s risk increases significantly after menopause, and a family history of heart disease is another important factor.
Symptoms and Clinical Manifestations
The most recognized symptom of IHD is chest discomfort known as angina pectoris. This sensation is often described as pressure, squeezing, or tightness in the chest. The discomfort can also radiate to the shoulders, arms, neck, jaw, or back and is often triggered by physical activity or emotional stress.
Angina is categorized into two main types. Stable angina is the more common form and follows a predictable pattern. It is triggered by exertion, lasts for five minutes or less, and is relieved by rest or medication, indicating underlying coronary artery disease.
Unstable angina is far more serious and is a medical emergency. It is unpredictable, can occur even at rest, and the pain is often more severe and lasts longer. This type of angina suggests a plaque has ruptured and a blood clot is forming, which can lead to a heart attack.
The most severe manifestation of IHD is a myocardial infarction, or heart attack. This occurs when blood flow to a part of the heart is completely blocked, causing heart muscle cells to die from lack of oxygen. Symptoms include intense chest pain, shortness of breath, a cold sweat, dizziness, and nausea.
The Diagnostic Process
Diagnosing IHD begins with a review of a patient’s medical history, risk factors, and symptoms, followed by a physical examination. This initial conversation helps a healthcare provider build a preliminary picture of the patient’s cardiovascular risk.
Following the initial assessment, non-invasive tests are ordered to evaluate the heart’s function. An electrocardiogram (ECG or EKG) records the heart’s electrical activity to show signs of a previous heart attack or ongoing ischemia. A stress test observes how the heart performs under physical demand, induced by exercise or medication.
An echocardiogram uses sound waves to create images of the heart, showing how its chambers and valves pump blood. This can identify areas of heart muscle not contracting properly due to poor blood flow. Blood tests can detect specific proteins released into the bloodstream when the heart muscle is damaged, which is important if a heart attack is suspected.
For a more definitive look at the coronary arteries, advanced imaging may be used, such as a cardiac computed tomography (CT) scan. The most definitive test is a coronary angiogram. During this procedure, a catheter guides a special dye into the coronary arteries, allowing X-rays to reveal the precise location and severity of any blockages.
Treatment and Management Strategies
The management of IHD is multifaceted, focusing on relieving symptoms, slowing the progression of atherosclerosis, and reducing the risk of future cardiac events. A foundational component of treatment involves significant lifestyle modifications. Adopting a heart-healthy diet, which emphasizes fruits, vegetables, and whole grains while limiting saturated fats and sodium, is a primary step.
Regular physical activity, as approved by a doctor, helps strengthen the heart muscle and manage other risk factors like high blood pressure and weight. For individuals who smoke, cessation is one of the most impactful changes they can make, as it can halt the ongoing damage to blood vessels. Learning to manage stress through techniques such as exercise or meditation can also be beneficial.
Medications are another pillar of IHD management. Statins are commonly prescribed to lower LDL (“bad”) cholesterol levels, which helps to stabilize plaque. Medications to control high blood pressure, such as beta-blockers or ACE inhibitors, reduce the heart’s workload. Antiplatelet agents, like low-dose aspirin, are used to prevent the formation of blood clots.
If significant blockages severely restrict blood flow, medical procedures may be necessary to restore it, a process known as revascularization. One common procedure is a percutaneous coronary intervention (PCI), often called angioplasty, where a balloon-tipped catheter is used to open a narrowed artery. A small mesh tube called a stent is often placed to keep it open. For more extensive disease, coronary artery bypass grafting (CABG) surgery may be recommended, where a healthy blood vessel from another part of the body is used to create a new path for blood to flow around the blockage.