Angina – Causes, Symptoms, Treatments

What is Angina?

Angina is a chest pain or discomfort that occurs when your heart doesn’t get enough oxygen-rich blood. This can happen due to various reasons, but the most common cause is coronary artery disease (CAD).

Coronary artery disease is a condition in which plaque (a fatty substance) builds up in the walls of the arteries that supply blood to the heart (coronary arteries). This buildup narrows the arteries and reduces blood flow to the heart muscle.

Relation between angina and CAD

Angina is not a disease itself, but rather a symptom of an underlying problem, most commonly CAD. When there’s a narrowing of the coronary arteries due to plaque buildup, the heart muscle isn’t getting enough oxygen-rich blood, especially during exertion or times of stress. This lack of oxygen supply can cause chest pain, tightness, or discomfort, which is angina.

Types of Angina

There are four main types of angina:

• Stable angina is the most common type of angina. It occurs when the heart muscle doesn’t get enough blood flow, usually due to narrowed coronary arteries caused by plaque buildup (atherosclerosis). Stable angina typically occurs predictably with exertion (like physical activity) or emotional stress, and goes away with rest or nitroglycerin medication. The chest pain is usually described as a squeezing, pressure, or tightness in the chest, and may radiate to the shoulder, arm, jaw, or back.
• Unstable angina is a more serious type of angina that can be a sign of an impending heart attack. Unlike stable angina, unstable angina can occur at rest, is unpredictable, and may not respond well to rest or medication. Unstable angina is a medical emergency and requires immediate medical attention.
• Microvascular angina is caused by narrowing of the smallest arteries that supply blood to the heart. The symptoms of microvascular angina can be similar to stable angina, but the chest pain may be more atypical and be accompanied by shortness of breath and fatigue. Microvascular angina can be difficult to diagnose and treat.
• Variant angina (Prinzmetal angina) is a rare type of angina caused by spasms of the coronary arteries. Variant angina typically occurs at rest, often at night or early morning, and may be triggered by stress, smoking, or exposure to cold weather. The chest pain associated with variant angina can be severe and prolonged.

Symptoms of Angina

The most common symptom of angina is chest pain or discomfort. This pain can manifest in different ways, often described as:

• Squeezing
• Pressure
• Tightness
• Aching
• Burning

While chest pain is the hallmark symptom of angina, it’s important to note that it can also radiate to other parts of the upper body, including:

• Arms
• Shoulders
• Neck
• Jaw
• Back

Angina pain is often triggered by exertion (like physical activity) or emotional stress.The pain typically lasts for a few minutes and goes away with rest or nitroglycerin medication. Angina may also be accompanied by shortness of breath, nausea, sweating, or fatigue.

Angina Risk Factors

Angina risk factors can be broadly categorized into lifestyle habits and genetic predisposition. 

Lifestyle Risk Factors:

• Unhealthy Diet: A diet high in saturated and trans fats, cholesterol, and refined carbohydrates can contribute to plaque buildup in arteries, reducing blood flow to the heart.
• Smoking: Smoking damages blood vessels and increases inflammation throughout the body, worsening coronary artery disease and angina risk.
• Physical Inactivity: Lack of exercise weakens the heart muscle and reduces its ability to pump blood efficiently.
• Obesity: Excess weight puts a strain on the heart and increases the demand for oxygen-rich blood.
• Excessive Alcohol Consumption: Heavy alcohol intake can raise blood pressure, damage heart muscle, and contribute to angina.
• Stress: Chronic stress can increase heart rate and blood pressure, potentially triggering angina episodes.

Genetic Risk Factors:

• Family History: Having a close relative (parent, sibling) with coronary artery disease significantly increases your risk of angina.
• Race and Ethnicity: While risk factors can vary, certain populations may have a higher genetic predisposition to angina, such as African Americans and Hispanics.

Other Medical Conditions:

Certain medical conditions can also increase the risk of angina:

• High Blood Pressure (Hypertension): Uncontrolled hypertension forces the heart to work harder, increasing the risk of angina.
• Diabetes: Diabetes damages blood vessels and increases the risk of plaque buildup.
• High Cholesterol: High levels of LDL (“bad”) cholesterol contribute to plaque formation in arteries.

Potential Complications of Untreated Angina

Angina is a symptom of coronary artery disease (CAD), a condition where plaque buildup narrows the coronary arteries that supply blood to the heart muscle. This reduced blood flow can cause angina pain when the heart demands more oxygen than it’s receiving.

A narrowed artery due to CAD is more susceptible to complete blockage by a blood clot. This complete blockage can lead to a heart attack, a life-threatening event where a portion of the heart muscle dies due to lack of oxygen. This is the most serious complication of untreated angina. A complete blockage of a coronary artery by a blood clot can lead to a heart attack, causing permanent damage to the heart muscle and potentially leading to death. Untreated angina significantly increases your risk of a heart attack, with potentially devastating consequences.

Over time, if the heart muscle doesn’t receive enough oxygen-rich blood due to CAD, it can weaken and become less efficient at pumping blood. This can lead to heart failure, a condition where the heart struggles to meet the body’s demand for blood.

In some cases, people with CAD may experience silent ischemia, a condition where they don’t experience angina symptoms despite reduced blood flow to the heart. This can be particularly dangerous as it delays seeking medical attention and increases the risk of a sudden heart attack.

Angina and CAD can increase the risk of irregular heartbeats (arrhythmias). Some arrhythmias can be life-threatening if not treated promptly. In rare cases, a severe blockage or spasm of a coronary artery can lead to sudden cardiac death, where the heart stops beating abruptly.

Left untreated, angina symptoms may worsen over time. This indicates progressive narrowing of the coronary arteries. This can lead to more frequent and severe angina attacks, limiting your daily activities and overall quality of life.

How is Angina Diagnosed?

Diagnosing angina typically involves a multi-step approach to assess your symptoms, medical history, and risk factors. Your doctor will start by asking detailed questions about your symptoms, including the nature of chest pain (location, intensity, duration), triggers (exertion, stress, rest), relieving factors (rest, medication) and whether there is a family history of heart disease.

A physical exam will assess your overall health and check for signs of heart problems like abnormal heart sounds or high blood pressure.

An Electrocardiogram (ECG) is a painless test that records the electrical activity of your heart using electrodes attached to your chest, arms, and legs. While an ECG can sometimes detect abnormalities suggestive of angina or previous heart damage, a normal ECG doesn’t rule out angina.

Another standard tool often used in testing for angina are blood tests. Blood tests can be used to measure cardiac enzymes like troponin, which can be elevated after a heart attack or severe angina episode. They are also used to check cholesterol levels (LDL, HDL) in order to assess your risk of coronary artery disease, and to identify other conditions like diabetes or anemia that might contribute to symptoms.

Depending on your situation, additional imaging tests may be used to visualize your heart and coronary arteries. While not a definitive test for angina, a chest X-ray can help rule out other lung-related causes of chest pain.

An Echocardiogram is an ultrasound technique that creates images of your heart structure and function, revealing abnormalities in heart wall movement or valve function.

Stress Tests measure your heart’s response to exertion (exercise on a treadmill or with medication) while monitoring heart rate, blood pressure, and ECG for signs of reduced blood flow during exercise.

A Coronary Angiography involves injecting a contrast dye into your coronary arteries to visualize blockages or narrowed pathways. An angiogram typically is not done until other noninvasive tests are used to check the heart. By combining the information from these methods, your doctor can arrive at an accurate diagnosis of angina and determine the type (stable, unstable, etc.) to guide the most appropriate treatment plan.

Angina treatment focuses on two main goals:

1. Symptom Relief: Reducing the frequency and severity of chest pain episodes to improve your quality of life and ability to perform daily activities.
2. Preventing Complications: Lowering your risk of a heart attack, stroke, or other cardiovascular events by addressing the underlying cause of angina – usually coronary artery disease (CAD).

Here’s a breakdown of the different approaches used to achieve these goals:

Lifestyle Modifications:

• Diet: A heart-healthy diet low in saturated and trans fats, cholesterol, and refined carbohydrates is crucial. Opt for fruits, vegetables, whole grains, lean protein, and healthy fats like those found in fish and olive oil.
• Exercise: Regular physical activity strengthens your heart muscle, improves blood flow, and helps manage weight. Aim for at least 150 minutes of moderate-intensity exercise (brisk walking) or 75 minutes of vigorous-intensity exercise (running) per week.
• Weight Management: If you’re overweight or obese, losing even a small amount of weight can significantly improve your heart health and reduce angina symptoms.
• Smoking Cessation: Smoking damages blood vessels and increases inflammation, worsening angina. Quitting smoking is one of the most important lifestyle changes you can make.
• Stress Management: Chronic stress can trigger angina episodes. Techniques like yoga, meditation, and deep breathing can help manage stress and improve heart health.

Medications:

Several medications can help manage angina by improving blood flow to the heart and reducing the workload on the heart muscle:

• Nitroglycerin: This fast-acting medication comes in spray, tablet, or sublingual form and is used to relieve angina symptoms during an attack. It relaxes blood vessels, increasing blood flow to the heart and reducing chest pain. It comes in various forms like spray, sublingual tablets (dissolve under the tongue), and ointment.
• Beta-blockers: These medications slow down your heart rate and reduce the force of your heart contractions, decreasing the heart’s oxygen demand and easing angina symptoms. Examples: Metoprolol, Atenolol, Bisoprolol.
• Calcium Channel Blockers: These medications relax the coronary arteries, allowing for better blood flow to the heart and reducing chest pain. Examples: Amlodipine, Felodipine, Nifedipine.
• Cholesterol-Lowering Medications: Statins are the mainstay of cholesterol management, lowering LDL (“bad”) cholesterol levels and slowing down plaque buildup in arteries. Examples: Atorvastatin, Rosuvastatin, Simvastatin.
• Antiplatelet Drugs: Medications like aspirin or clopidogrel help prevent blood clots from forming in the coronary arteries, which can worsen angina or trigger a heart attack.

Other Treatment Approaches:

In some cases, depending on the severity of angina and the extent of coronary artery blockage, your doctor might recommend procedures like:

• Angioplasty and Stenting: A minimally invasive procedure where a catheter is inserted into a blocked artery and a balloon is used to open it. A stent may be placed to keep the artery open.
• Coronary Artery Bypass Grafting (CABG): This open-heart surgery involves bypassing blocked coronary arteries with healthy blood vessels from another part of your body.