KDE | Chapter One: Cardiovascular Disease
Introduction to Cardiovascular Disease
Heart disease accounts for one in every four deaths in the U.S., according to the Centers for Disease Control and Prevention (CDC).
Cardiovascular disease (CVD) is a general term for conditions affecting the heart or blood vessels. These conditions develop when plaque builds up in the arteries (atherosclerosis), causing a narrowing of the interior of the arteries. As the arteries narrow, the flow of blood is decreased or blocked. In some cases, plaques can rupture and cause blood clots to form. CVD types include stroke, coronary heart disease, arrhythmias, congenital heart defects, high blood pressure, and rheumatic heart disease. However, according to the CDC, coronary heart disease is the most common type of heart condition.
Anatomy of the Heart
The heart is a muscular organ about the size of one’s fist, located slightly left of center in the chest. It is divided into the right and the left sides. Four heart valves keep the blood moving right by opening only one way and only when needed. For the heart to work as intended, the valves must be adequately formed, extended all the way, and close the leaflets sufficiently so there is no leakage or regurgitation.
A beating heart squeezes (contracts) and relaxes in a continuous cycle. During contraction (systole), the ventricles squeeze tight, forcing blood into your lungs and body vessels. During relaxation (diastole), the ventricles are filled with blood from the upper chambers (left and right atria).
A natural pacemaker (the sinus node) controls the heart’s rhythm in the right upper chamber (atrium). The sinus node sends electrical signals that initiate heartbeats. Usually at rest, as the electrical impulse moves through the heart, the heart contracts about 60 to 100 times a minute, depending on a person’s age.
The Coronary Arteries
The coronary arteries deliver blood to the heart muscle. Like all other tissues in the body, the heart muscle needs oxygen-rich blood to function, and oxygen-depleted blood must be carried away. The coronary arteries run outside the heart and have small branches that supply blood to the heart muscle. Any coronary artery disorder or disease can impact the flow of oxygen and nutrients to the heart, possibly leading to a heart attack and death. The most common cause of heart disease is atherosclerosis, a buildup of plaque in the inner lining of an artery causing it to narrow or become blocked.
Common Types of Cardiovascular Conditions and Diseases
Angina is chest pain caused by reduced blood flow to the heart muscles. It’s not usually life-threatening, but it’s a warning sign that one could be at risk of a heart attack or stroke. A buildup of fatty substances generally causes angina and atherosclerosis, effectively narrowing the arteries supplying blood to the heart muscles. However, with treatment and healthy lifestyle changes, it’s possible to control angina and reduce the risk of these more severe problems.
The main symptom of angina is chest pain. Chest pain caused by angina usually feels tight, dull, or heavy. It is triggered by physical exertion or stress and stops within a few minutes of resting. However, there might be other symptoms, like feeling sick or breathless.
The treatment for angina usually includes taking several different medicines. An operation may be recommended if medications are unsuitable or do not help. However, if it’s well controlled, one can usually continue to do most of one’s everyday activities. Therefore, one of the most important treatments is making healthy lifestyle changes.
A heart attack (myocardial infarction or MI) is a serious medical emergency in which the blood supply to the heart is suddenly blocked, usually by a blood clot. The lack of blood in the heart may seriously damage the heart muscle and can be life-threatening.
The symptoms of a heart attack can include:
Pain in other parts of the body
Feeling lightheaded or dizzy
Shortness of breath
Feeling sick (nausea)
Being sick (vomiting)
An overwhelming feeling of anxiety (similar to a panic attack)
Coughing or wheezing
The chest pain is often severe, but some people may only experience minor pain, similar to indigestion. While the most common symptom in both men and women is chest pain, women are more likely to have other symptoms such as shortness of breath, feeling or being sick, and back or jaw pain.
Unless there is an allergy to aspirin, it may help to chew and swallow an aspirin tablet. In the hospital, treatment for a heart attack depends on how serious it is. The two main treatments are medicines to dissolve blood clots and surgery to help restore blood to the heart. The leading cause of heart attacks is coronary heart disease.
Heart failure means the heart cannot pump sufficient blood around the body, as the heart has become too weak or stiff. It’s sometimes called congestive heart failure, although the term falls out of fashion. Heart failure means the heart needs some support to function fully. Whereas heart failure can occur at any age, the risk increases with age. Heart failure is a long-term condition that worsens gradually over time. It cannot usually be cured, but the symptoms can often be controlled for many years.
The main symptoms of heart failure are breathlessness after activity or at rest, constant tiredness, fatigue after exercise, lightheaded or fainting, and swollen ankles and legs. In addition, other less common symptoms are persistent cough, a rapid heart rate, and dizziness. Acute heart failure symptoms emerge rapidly, whereas chronic heart failure gradually appears over weeks or months.
Heart failure is often the result of several problems affecting the heart simultaneously. Conditions that can lead to heart failure include coronary heart disease, high blood pressure, cardiomyopathy, arrhythmias, damage or other issues with the heart valves, and congenital heart disease. Sometimes obesity, anemia, drinking too much alcohol, an overactive thyroid, or high lung pressure (pulmonary hypertension) can also lead to heart failure.
Treatment for heart failure predominately addresses symptoms and slows down disease progression. However, treatment varies with the origin of the disease. Common treatments include lifestyle changes, medicine, devices implanted in your chest, and surgery – such as a bypass operation or a heart transplant.
Heart failure is a no-nonsense long-term condition that will worsen gradually over time. It can restrain many activities, and it is not unusual to be fatal in the long run. But it’s challenging to tell how the condition will progress on an individual basis as it is very unpredictable.
Coronary Artery Disease
Coronary heart disease, or coronary artery disease (CAD), is characterized by inflammation and the buildup of fatty deposits along the innermost layer of the coronary arteries. The fatty deposits may develop in childhood and continue to thicken and enlarge throughout life. This thickening, atherosclerosis, narrows the arteries and can decrease or block blood flow to the heart. As a result, the American Heart Association estimates that over 16 million Americans have coronary artery disease – the number one killer in the U.S.
The symptoms of coronary heart disease will depend on the severity of the disease. For example, some people with CAD have no symptoms, some have mild chest pain or angina episodes, and some have more severe chest pain.
Coronary artery disease is diagnosed with a complete medical history in combination with a physical exam and tests. Tests can include an electrocardiogram (ECG or EKG), a stress test (also called treadmill or exercise ECG), cardiac catheterization, or nuclear scanning. Treatment may include lowering risk factors, medicines, or coronary angioplasty
Blood clots can be life-threatening if not treated quickly. Symptoms of a blood clot include throbbing or cramping pain, swelling, redness, warmth in a leg or arm or sudden breathlessness, sharp chest pain (may be worse when you breathe), and a cough or coughing up blood.
Blood clots are rare in young, healthy people. The likelihood of blood clots forming during or after hospitalizations – especially if one cannot move around much (like after an operation). Additionally, blood clots in overweight people smoke, use combined hormonal contraception such as the combined pill, contraceptive patch, or vaginal ring, have had a blood clot before, are pregnant, or have just had a baby. Inflammatory conditions such as rheumatoid arthritis or Crohns disease can also trigger clots.
Staying healthy and active can help prevent blood clots. Other ways of preventing blood clots include wearing stockings that improve the blood flow or taking medicine to reduce the risk of clots (anticoagulants) and lowering risk factors.
Strokes and TIAs
A stroke is where the blood supply to part of the brain is cut off, which can cause brain damage and possibly death. An ischemic stroke is caused by a blockage cutting the blood supply to the brain. Ischemic stroke is the most common type of stroke.
A hemorrhagic stroke is caused by bleeding in or around the brain. A transient ischemic attack (also called a TIA or “mini-stroke”) is similar, but the blood flow to the brain is only temporarily disrupted. As we age, the arteries become stiffer, narrower, and more likely to become blocked. However, certain medical conditions and lifestyle factors can speed up this process and increase the stroke risk.
All strokes are different. For some people, the effects may be relatively minor and not last long. Others may be left with more severe problems that make them dependent on others. Unfortunately, some strokes can be cruel and may lead to coma or sudden death. That’s why it’s so important to be able to recognize the symptoms and get medical help as quickly
as possible. The faster one receives treatment after a stroke, the better the chances for a good recovery.
Peripheral Arterial Disease
PAD can cause dull or cramping leg pain, which is worse when walking and gets better with rest, hair loss on the legs and feet, numbness or weakness in the legs, or persistent ulcers (open sores) on the feet and legs.
Aortic diseases are a group of conditions affecting the aorta. The aorta is the largest blood vessel, which carries blood from the heart to the rest of the body.
An aortic aneurysm is one of the most common aortic diseases, where the aorta becomes weakened and bulges outwards. An aneurysm doesn’t usually have any symptoms, but there’s a chance it could burst and cause life-threatening bleeding. Treating a thoracic aortic aneurysm includes a spectrum from regular health checkups to emergency surgery. The pathology (cause) of the aneurysm decides the treatment.
Peripheral arterial disease (PAD) is a common condition where a buildup of fatty deposits
in the arteries restricts blood supply to leg muscles. It’s also known as a peripheral
vascular disease (PVD).
Signs and symptoms of a ruptured or dissected thoracic aortic aneurysm include:
Sharp, sudden pain in the upper back that spreads downward
Pain in the chest, jaw, neck, or arms
Low blood pressure
Loss of consciousness
Shortness of breath
Thoracic aortic aneurysms are less common than aneurysms in the lower part of the
aorta (abdominal aortic aneurysms)
Atherosclerosis is a potentially serious condition where arteries become clogged with fatty substances called plaques, or atheroma. Deposits of fatty substances, cholesterol, cellular waste products, calcium, and fibrin make up plaque. The walls become thickened and stiff as it builds up in the arteries. These plaques cause the arteries to harden and narrow, restricting the blood flow and oxygen supply to vital organs and increasing the risk of blood clots that could block blood flow to the heart or brain.
Atherosclerosis is a slow, progressive disease that may start as early as childhood. The condition does not tend to have symptoms initially, and many people may be unaware they have it. However, atherosclerosis can progress rapidly if it worsens and eventually causes life-threatening problems like heart attacks and strokes. There will not usually be any symptoms until cardiovascular disease (CVD) develops.
Atherosclerosis is diagnosed with one’s medical history, a physical exam, and one or more of these tests:
Blood pressure comparison
Thallium/myocardial perfusion scan
Computerized tomography or CT
The condition is largely preventable with lifestyle changes, such as a healthy diet and regular exercise. Treatment can help reduce the risk of serious problems, but in some cases, medication or surgical procedures may be required.
Ventricular tachycardia concerns irregular heart rhythm problems (arrhythmia). Arrhythmia is caused by irregular electrical signals in the lower chambers of the heart (ventricles). Other names for this condition are V-tach or VT. A healthy heart typically beats about 60 to 100 times a minute at rest. However, the heart beats faster, usually 100 or more beats a minute for people with ventricular tachycardia.
Ventricular tachycardia may disappear by itself within 30 seconds (non-sustained V-tach) or last more than 30 seconds (sustained V-tach or VT). When the heart is rushing, it may not pump enough blood to the rest of the body, leading to the organs and tissues not getting enough oxygen. Brief episodes may not cause symptoms, but sustained VT can cause serious problems, including fainting, losing consciousness, or causing the heart to stop (sudden cardiac arrest).
Several factors can cause or contribute to problems with heart signaling and lead to ventricular tachycardia, including prior heart attack or other heart conditions that cause scarring of heart tissue (structural heart disease). Additional causes for ventricular tachycardia are poor blood flow to the heart muscle due to coronary artery disease or congenital heart diseases, including long QT syndrome. However, the exact cause of ventricular tachycardia cannot always be established (idiopathic ventricular tachycardia).
Signs and symptoms during an episode of ventricular tachycardia are due to a lack of oxygen. They may include chest pain (angina), dizziness, pounding heartbeat (palpitations), lightheadedness, and shortness of breath.
Treatment for ventricular tachycardia may include medication, a shock to the heart (cardioversion), catheter procedures, or surgery to slow the fast heart rate and reset the heart rhythm. In addition, treatments include ablation (surgical tissue removal) and an implanted defibrillator.
Complications of heart disease include:
Heart failure. One of the most common complications of heart disease, heart failure, manifests itself by an inability to pump enough blood to meet the body’s needs. Heart failure can result from heart disease, including heart defects, cardiovascular disease, valvular heart disease, heart infections, or cardiomyopathy.
Heart attack. A blood clot blocking the blood flow through a blood vessel that feeds the heart causes a heart attack, possibly damaging or destroying a part of the heart muscle. In addition, atherosclerosis can cause a heart attack.
Stroke. The risk factors that lead to cardiovascular disease can also lead to an ischemic stroke, which happens when the arteries to the brain are narrowed or blocked so that too little blood reaches the brain. A stroke is a medical emergency — brain tissue begins to die within just a few minutes of a stroke.
Aneurysm. An aneurysm is a bulge in the artery wall that can occur anywhere in the body. If an aneurysm bursts, one may face life-threatening internal bleeding.
Peripheral artery disease. When one develops peripheral artery disease, the extremities — usually the legs — don’t receive enough blood flow. The loss of blood flow causes symptoms, most notably leg pain when walking (claudication). Atherosclerosis can also lead to peripheral artery disease.
Sudden cardiac arrest. Sudden cardiac arrest is the sudden, unexpected loss of heart function, breathing, and consciousness, often caused by an arrhythmia. Sudden cardiac arrest is the most urgent medical emergency. If not treated immediately, it results in sudden cardiac death.
Risk Factors for Cardiovascular Disease
Age, Gender, and Heritage
Growing older increases the risk of damaged and narrowed arteries and weakened or thickened heart muscle. Men are generally at greater risk of heart disease, though the risk for women increases after menopause.
Family history is a factor; a history of heart disease would increase the risk of coronary artery disease, especially for an early onset in a parent.
People of south Asian and Black African or African Caribbean background have an increased risk of CVD. This risk factor is due to a genetic disposition for CVD, such as high blood pressure or type 2 diabetes.
Smoking is a risk factor, as nicotine tightens the blood vessels, and carbon monoxide can damage their inner lining, making them more susceptible to atherosclerosis. As a result, heart attacks are more common in smokers than nonsmokers.
A poor diet high in fat, salt, sugar, and cholesterol can contribute to the development of heart disease.
Using stimulant drugs such as cocaine or methamphetamine may increase the risk.
Excess weight typically worsens other heart disease risk factors. Lack of exercise is also associated with many heart diseases and other risk factors.
Unrelieved stress may damage your arteries and worsen other risk factors for heart disease.
Hypertension is a significant risk for cardiovascular complications, and reading the KDE chapter about hypertension is recommended. In addition, high cholesterol levels in the blood can increase the risk of plaque formation and atherosclerosis.
Medication for other illnesses may have side effects. Diabetes increases the risk of heart disease.
Brushing and flossing one’s teeth and gums often and having regular dental checkups are essential. If the teeth and gums aren’t healthy, germs can enter the bloodstream and travel to the heart, causing endocarditis.
Congenital heart defects usually develop while a baby is in the womb. However, heart defects can develop as the heart develops, about a month after conception, changing the flow of blood in the heart. In addition, some medical conditions, medications, and genes
may play a role in causing heart defects. Heart defects can also develop in adults. In addition, the heart’s structure can change as one age, causing a heart defect.
Prevention of Cardiovascular Disease
Certain types of heart disease, such as heart defects, can’t be prevented. However, the same lifestyle factors that can accelerate heart disease can help prevent it if managed correctly. Here are the key points to a healthy heart.
Maintain a balanced and nutritious diet; the DASH diet is a good starting point. A healthy diet includes fruits, vegetables, whole grains, lean meats, skinless chicken, seafood, and fat-free or low-fat dairy products. A healthy diet also limits sodium, refined sugars, grains, and solid fats. Make sure to modify the DASH diet to account for the kidney status.
Exercise regularly. Shoot for at least 30 minutes of moderate daily exercise or 8,000 steps as a general goal. Maintain a healthy weight and aim for a body mass index (BMI) of 18.5 to 24.9, as being overweight increases the risk of developing heart disease. Don’t use illegal drugs or stimulants, such as cocaine. Limit alcohol and caffeine and stop smoking.
Control stress. Avoid unnecessary stress and apply strategies to manage and reduce stress.
Control other health conditions, such as high blood pressure, high cholesterol, and diabetes. Make lifestyle changes and take medications to manage high blood pressure (hypertension) or high cholesterol.
Use over-the-counter medications with caution. For example, some cold and cough medicines contain stimulants that may increase the heart rate.