Re-entry is a cardiac arrhythmia that occurs when the electrical impulses of the heart are propagated in tight circles, rather than being propagated from one end of the heart to the other.

Fibrillation refers to a condition where multiple groups of heart cells beat independently and out of sync, resulting in a chaotic contraction of the heart. Fibrillation can affect both chambers of the heart, the atrium as well as the ventricle (ventricular fibrillation is imminently life-threatening).

Bradycardia refers to heart rates that are too slow (less than 60 beats/min.). Bradycardias often result from irregular electrical activity of the sinus node, the pacemaker tissue of the heart. The sinus node signal can be either too slow, termed sinus bradycardia, or temporary paused (sinus arrest). Other bradycardias are related to the lack of proper electrical signal transmission from the atria (top heart chambers) to the ventricles (bottom heart chambers).

A cardiac arrhythmia, where heart cells other than the pacemaker cells trigger the heartbeat. The resulting heart rhythms range from rhythms that remain normal but rapid to rhythms that are highly irregular.

Tachycardia refers to heart rates that are abnormally fast (more than 100 beats/min. resting pulse). There are many different reasons why heart rates might be accelerated, some are a normal response to physical exercise or emotional stress, but others are more serious and have their basis in abnormal impulses of heart cells.

A condition where the sinus node generates an electrical signal that is too slow.

The sinus node is the impulse-generating (pacemaker) tissue located in the right atrium of the heart, responsible for the beating of the normal heart. Sinus arrest refers to a condition where the sinus node temporarily ceases to generate the needed electrical impulses that induce the heart to beat.

Cardiac arrhythmias are disorders in which there is abnormal electrical activity in the heart. Such disorders manifest in the heart beating too fast (tachycardia) or too slow (bradycardia), or might manifest in a highly irregular heartbeat (automaticity, re-entry, fibrillation).

Stenosis is an abnormal narrowing of a tubular organ, usually a blood vessel.

Blood pressure is the force the blood exerts against the arterial wall. Blood pressure consists of two values measured in millimeters of mercury (mm Hg): the pressure when the heart beats (systolic pressure), and the pressure when the heart is at rest (diastolic pressure). In adults, values greater than140 mm Hg systolic pressure or values greater than 90 mm Hg diastolic pressure are considered high blood pressure. High blood pressure directly increases the risk of heart attack and stroke.

A medical condition where an artery wall thickens as a result of a build-up of fatty materials. Sometimes, atherosclerosis is used as synonym for cardiovascular diseases.

At the cellular level, atherosclerosis results from an interaction between cholesterol, oxidation (a chemical process) and the inflammatory response. Many other factors such as genetic predisposition, sex, age and lifestyle contribute to the progression of atherosclerosis.

Some risk factors, such as age, or genetic predisposition are given and cannot be changed. However other major risk factors are under your control (lifestyle choice, medication). Risk factors that are under your control are: high blood pressure, smoking tobacco, high blood cholesterol, overweight and physical exercise.

As the degree of atherosclerosis increases two potentially life-threatening conditions are developing. First, the plaque buildup causes a narrowing of the arteries, reducing blood flow to the heart muscle tissue. As a result, some heart muscle cells are deprived of sufficient oxygen and nutrients, which may lead to permanent injury or may lead to a heart attack. At the same time, the narrowing of the arteries causes the blood pressure to rise, increasing the risk of hemorrhages (bleedings) in small arteries. If the hemorrhages occur in the brain it may lead to a stroke.

A plaque is an accumulation of hardened cells or cell debris on artery walls.

The approach for managing any degree of cardiovascular disease revolves around the prevention and treatment of atherosclerosis. Prevention consists of a variety of medications and adopting healthier lifestyles, whereas treatment of advance degrees of atherosclerosis includes surgery as well as medication. The choice of strategy managing cardiovascular disease is tailored to each individual patient, depending on severity and individual conditions.

High blood pressure is a major risk factor for stroke, heart attack and heart failure. The sooner it is taken care of the less serious its complications will become.

Statins are newly developed drugs that lower the low-density lipoproteins (LDL), the so-called “bad” cholesterol in the blood.

Examples of antiplatelet drugs are cyclooxygenase inhibitors like Aspirin, adenosine diphosphate receptor inhibitors like clopidogrel (Plavix) and ticlopidine (Ticlid), glycoprotein IIB/IIIA inhibitors like abciximab (ReoPro), eptifibatide (Integrilin), and tirofiban (Aggrastat), and adenosine reuptake inhibitors like dipyridamole (Persantine).

Examples of anticoagulants are low-molecular weight heparins like enoxaparin (Lovenox), dalteparin (Fragmin), tinzaparin (Innohep), warfarin (Coumadin) and direct thrombin inhibitors (DTIs) like bivalirudin (Angiomax), ximelagatran (Exanta), argatroban (Novastan), danaparoid (Orgaran), lepirudin (Refludan) and desirudin (Revasc).

Calcium channel blockers are a class of drugs that reduce the heart rate and lower the blood pressure.

Beta-blockers are a class of drugs that reduce the heart rate and lower the blood pressure. They are prescribed to patients at risk of heart and angina attacks (e.g. people with high blood pressure) or to patients with abnormal heart activity (cardiac arrhythmias). Beta-Blockers are also used for reducing the risk of death during the recovery after heart surgeries.

Antiplatelets are a class of different drugs that decrease or disable the aggregation of blood platelets that may cause heart attacks and strokes. Antiplatelets inhibit the production of thromboxane, a chemical signal that makes the platelets aggregate.

Anticoagulants are a class of different drugs that prevent blood coagulation and the formation of blood clots that may cause heart attacks and strokes. More specifically, they target clotting factors, proteins that are crucial to the blood-clotting process.

Regularly physical activity can reduce the risk of heart disease. Physical activity also helps to control weight, can reduce high blood pressure and high cholesterol. Furthermore, physical activity reduces stress, which may also be a factor in heart disease. Physicians recommend 30 to 60 minutes of moderately intense physical activity most days of the week. However, any amount and type of exercise (e.g. taking the stairs, gardening, housekeeping) will benefit the heart.

This question is a bit misleading, as there is no such thing as good or bad cholesterol. The term refers to the two types of transport molecules (high-density lipoprotein, low-density lipoprotein) that are responsible for transporting cholesterol through the bloodstream. It is believed that the high-density lipoprotein (HDL) can remove cholesterol from arteries. Hence, HDL is sometimes referred to as "good cholesterol". On the other hand, high levels of low-density lipoprotein may indicate medical problems associated with cardiovascular disease. Hence, LDL-cholesterol is sometimes referred to as "bad cholesterol".

Cholesterol is a steroid, a fat-like substance found in animal cell membranes and some hormones. It is normal to have cholesterol and serves important bodily functions. However, excessive levels of cholesterol in the blood circulation is an indication for atherosclerosis.

The chance of developing heart disease depends on many factors such as genetic predisposition, sex, age, and lifestyle. Although you cannot change your genetic predisposition or age, you have the power to change lifestyle risk factors leading to heart disease. The key steps to heart disease prevention are: don’t smoke, get regular exercise and eat healthy foods. It is also advisable to get regular health checkups to determine your blood pressure, cholesterol levels, and body fat. Because without testing for them, you probably would not know if you need to take any action.

Eating a healthy diet means eating foods that are low in fat, cholesterol and salt. Such diets emphasize vegetables, fruits and whole grains. Legumes (beans, lentils, peas, soybean, peanuts) and certain types of fish are an excellent low-fat source of protein.

Foods high in saturated fats should be reduced as they contribute to atherosclerosis and coronary heart disease. Examples include dairy products, animal fats, coconut oil, cottonseed oil, palm oil and chocolate.

There is growing evidence that trans fats may be worse than saturated fats, and should be avoided if possible. Because unlike saturated fats, trans fats raise not only your "bad cholesterol” but lower the "good cholesterol” as well. Examples of food containing saturated fats are deep-fried fast foods, bakery products, packaged snack foods, crackers and margarines. The term “partially hydrogenated” on food packages is a good indication that such foods contain trans fats.

On the other hand, polyunsaturated fats, like omega-3 fatty acids, may decrease your risk of having a heart attack and lower your blood pressure. Some fish are an excellent source of omega-3 fatty acids, but increasing concerns of toxic levels of heavy metals (e.g. mercury) makes fish as a source of omega-3 fatty acids less ideal. A better source, although less concentrated, are omega-3 fatty acids from walnut, flaxseed or canola oil. Omega-3 fatty acids are also available in food supplements.

High levels of cholesterol increase the risk of heart disease. The most severe manifestation of heart disease is the stroke and the heart attack.

Unsaturated fats are fats with one or more double bonds in the fatty acid chain. They help to lower levels of total cholesterol and LDL-cholesterol in the blood. Foods containing unsaturated fats include avocado, nuts, and some vegetable oils (i.e. canola, olive, sunflower) and some fish oil.

Trans fats are a special kind of unsaturated fats used in the food industry to increase the shelf-life of a product. Trans fats are not essential and their consumption increases the risk of coronary heart disease by raising levels of "bad cholesterol" and lowering levels of "good cholesterol". Examples of food containing saturated fats are deep-fried fast foods, bakery products, packaged snack foods, crackers and margarines. The term “partially hydrogenated” on food packages is a good indication that such foods contain trans fats.

Saturated fats are fats that contain only saturated fatty acid radicals. Diets high in saturated fats are thought to contribute significantly to atherosclerosis and coronary heart disease. Foods that contain high proportion of saturated fats include dairy products, animal fats, coconut oil, cottonseed oil, palm oil and chocolate.

Omega-3 fatty acids are special types of unsaturated fatty acids. They are considered essential nutrients, as the human body is not able to synthesize them. They help to lower levels of total cholesterol and LDL-cholesterol in the blood. Foods that contain high proportion of Omega-3 fatty acids include flaxseeds, walnuts, some fish (salmon, halibut), tofu and winter squash.

Low-density lipoprotein (LDL) is a type of lipoprotein that transports cholesterol and other fats trough the blood stream. High levels of LDL-cholesterol can indicate medical problems associated with cardiovascular disease. Hence, LDL-cholesterol is sometimes referred to as "bad cholesterol".

Lipoproteins are molecules that are a combination of proteins and lipids. In the human body, many different types of molecules belong to the class of lipoproteins; examples include enzymes, transporters, or structural proteins. Important examples are the high-density (HDL) and low-density lipoproteins (LDL), which are responsible for the transport of fat (e.g. cholesterol) through the blood stream.

High-density lipoprotein (HDL) is a type of lipoprotein that transports cholesterol and other fats trough the blood stream. It is believed that HDL can remove cholesterol from arteries. Hence, HDL-cholesterol is sometimes referred to as "good cholesterol".

Atria (sing. atrium) are the upper chambers of the mammal heart (including humans). The mammal heart contains four chambers: the right atrium, the left atrium, the right ventricle and the left ventricle. The right atrium receives de-oxygenated blood from the body; the left atrium receives oxygenated blood from the lungs.

Ventricles are the lower chambers of the mammal heart (including humans). The mammal heart contains four chambers: the right atrium, the left atrium, the right ventricle and the left ventricle. The ventricle collects blood from either the left or right the atrium and pumps it out of the heart (either to the lungs or into the body).

A heart disease that develops before birth.

Heart diseases is an umbrella term for a variety of different diseases relating to the heart. Such afflictions include diseases affecting the blood vessels that supply the heart, deterioration of the function of the heart, inflammation of the heart muscle or diseases related to one or more heart valves. Far the most common type of heart disease is called atherosclerosis, a number of conditions in which an artery wall thickens due to a buildup of materials. The most severe manifestation of atherosclerosis is the stroke and the heart attack.

The blood vessels that deliver oxygen-rich blood to the muscle tissue of the heart.

Commonly referred to a number of conditions of specific diseases in which an artery wall thickens as the result of a build-up of fatty materials. These conditions are termed atherosclerosis by the medical professionals.

A specific type of chest pain caused by insufficient blood flow through the main blood vessels (coronary arteries) to the heart muscle. The pain is usually experienced under the breast bone, but may also radiate to the neck, jaw, or left shoulder and arm.

Occurs when the blood supply to the heart muscle is severely reduced or even entirely eliminated. This reduction of the blood flow occurs when one or more of the coronary arteries, the main arteries to the heart, are blocked. This is usually caused by the buildup of plaque (deposits of fat-like substances) within the coronary arteries, termed atherosclerosis.

Heart attacks are often depicted with intense pain and where a person suddenly clutches his or her chest and falls over. However, many heart attacks start slowly, as a mild pain or discomfort. The warning signs of a heart attack might include chest discomfort, discomfort in other areas of the upper body, shortness of breath, breaking out in a cold sweat, nausea, or light-headedness. Even if you are not sure whether you suffer from a heart attack, it is always advisable to have it checked out. Fast action saves lives.

The risk of having a heart attack depends strongly on your lifestyle. By living a healthy lifestyle you will reduce your risk considerably. A healthy lifestyle includes: maintaining a healthy body weight, not smoking, moderate physical exercise, controlling high blood pressure, eating low-cholesterol, low-fat foods.

An ischemia is a restriction in blood supply that may lead to damage or dysfunction of tissue. Hence, an ischemic stroke is a stroke caused by blockage of a blood vessel.

A stroke caused by a blood clot within the skull vault.

A stroke is a loss of brain function(s) due to disruption of the blood supply to the brain. Two main types of stroke can be distinguished: the ischemic stroke and the hemorrhagic stroke.

Hemorrhage is another word for bleeding - the loss of blood from the circulatory system. Hence, hemorrhagic strokes are strokes caused by ruptured arteries in the brain, flooding the surrounding tissue with blood.

Cerebral embolism is a special type of stroke where the blockage of the blood vessel is caused by a migrating blood clot originally formed in another part of the body.

Warning signs of a stroke appear sudden and without a known cause. The symptoms might include: strong headache, numbness of the face, arm or leg, trouble understanding or speaking, trouble seeing (one or both eyes), difficulty to walk, and loss of coordination or balance. Stroke is a medical emergency. Please call the medical emergency services. Because there are different types of strokes, the treatments for acute intervention and prevention are different.

The available tests fall into three main categories: imaging, blood flow tests and electrical tests. Imaging is used to create a picture of the brain. It provides crucial information about the cause of a stroke, and the location and extent of the injury. There are two techniques commonly used: computed tomography (CT or CAT Scans) and magnetic resonance imaging (MRI). Electrical tests show the brain’s electrical activity. Electroencephalograms (EEGs) simply measure brain’s electrical activity whereas an evoked response test measures how the brain handles sensory information related to hearing, body sensation or vision. Blood flow tests usually use ultrasound technology to determine the amount of blood flow through the blood vessel. Another method is angiography, where first a special dye is injected into the blood vessels, followed by X-ray photography.

The risk of having a stroke depends strongly on your lifestyle. By living a healthy lifestyle you will reduce your risk considerably. A healthy lifestyle includes: maintaining a healthy body weight, not smoking, regular physical exercise, controlling high blood pressure, eating low-cholesterol, low-fat foods.

Angioplasty performed on the coronary arteries.

Angioplasty is a collection of different procedures to mechanically widen narrowed or obstructed blood vessels (often as a result of atherosclerosis). Typically, a tightly folded balloon is inserted through a large artery to the location where the blood vessel is obstructed. Then, the balloon is inflated to press the plaque against the walls of the artery, opening the narrowed location. To keep the artery open after an angioplasty procedure surgeons insert an expandable metal mesh tube (stent) at the site of the blockage. Angioplasty was developed by Andreas Gruentzig and was performed for the first time in 1977 in Zurich, Switzerland.

An implantable cardioverter-defibrillator is a battery-powered electrical impulse generator which is implanted in patients. They counter the effects of fibrillation, a life-threatening event in which heart muscle cells contract chaotically.

Artificial pacemakers are devices that correct the irregular electrical activity of the sinus node, the natural pacemaker tissue of the heart. Irregular electrical activity of the sinus node might result in signals that are either too slow (sinus bradycardia) or in signals that are temporarily suspended (sinus arrest). Other irregularities might manifest in improper electrical signal transmission from the atria to the ventricles.

A stent is a tube inserted into a natural tubular organ, usually a blood vessel, in order to hold the structure open. Expandable stents are used after an angioplasty procedure to keep the artery open.

Re-closure of a previously opened blood vessel. Mostly referred to as reclosure of an opened blood vessel through an angioplasty procedure.

Coronary artery bypass surgery, or simply bypass, is a surgical procedure to relieve angina attacks, chest pain caused by insufficient blood flow to the heart muscle. Bypass surgery also reduces the risk of death from coronary artery disease. In the bypass procedure, arteries or veins from elsewhere in the patient’s body are taken to bypass atherosclerotic sections of the coronary arteries.

Bypass procedures are sometimes referred to by the number of coronary arteries bypassed. For example, a double bypass means two coronary arteries are bypassed, a triple bypass means three vessels are bypassed and so on. A greater number of bypasses does not necessarily imply a person is "sicker," nor does a smaller number necessarily imply a person is "healthier.

Bypass surgeries are usually performed with the heart stopped, where the circulation of blood (the function of the heart) and the oxygen content of the body (function of the lung) are maintained with a mechanical device, often referred to as heart-lung machines. Bypass operations can also be performed with the heart still beating, referred to as “off-pump” surgery.