Definition of Cardiovascular disease

Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest.

The heart is composed of specialized cardiac muscle, and it is four-chambered, with a right atrium and ventricle, and an anatomically separate left atrium and ventricle. The blood flows from the systemic veins into the right atrium, thence to the right ventricle, from which it is pumped to the lungs, then returned into the left atrium, thence to the left ventricle, from which it is driven into the systemic arteries.

The heart is thus functionally composed of two hearts: the right heart and the left heart. The right heart consists of the right atrium, which receives deoxygenated blood from the body, and the right ventricle which pumps it to the lungs under low pressure; and the left heart, consisting of the left atrium, which receives oxygenated blood from the lung, and the left ventricle, which pumps it out to the body under high pressure.

Definition of Arrhythmia

Arrhythmia: An abnormal heart rhythm.

In an arrhythmia the heartbeats may be too slow, too rapid, too irregular, or too early. Rapid arrhythmias (greater than 100 beats per minute) are called tachycardias. Slow arrhythmias (slower than 60 beats per minute) are called bradycardias. Irregular heart rhythms are called fibrillations (as in atrial fibrillation and ventricular fibrillation). When a single heartbeat occurs earlier than normal, it is called a premature contraction.

The term arrhythmia comes from the Greek a-, loss + rhythmos, rhythm = loss of rhythm.


Common Misspellings: erythremia, arythmia

Definition of Heart Failure

Heart failure - Inability of the heart to keep up with the demands on it and, specifically, failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs such as the brain, liver and kidneys. Heart failure may be due to failure of the right or left or both ventricles. The signs and symptoms depend upon which side of the heart is failing. They can include shortness of breath (dyspnea), asthma due to the heart (cardiac asthma), pooling of blood (stasis) in the general body (systemic) circulation or in the liver's (portal) circulation, swelling (edema), blueness or duskiness (cyanosis), and enlargement (hypertrophy) of the heart.

There are many causes of congestive heart failure including: (1) coronary artery disease leading to heart attacks and heart muscle weakness, (2) primary heart muscle weakness from viral infections or toxins such as prolonged alcohol exposure, (3) heart valve disease causing heart muscle weakness due to too much leaking of blood or heart muscle stiffness from a blocked valve, and (4) hypertension (high blood pressure). Rarer causes include hyperthyroidism (high thyroid hormone), vitamin deficiency, and excess amphetamine ("speed") use.

The aim of therapy is to improve the pumping function of the heart. General treatment includes salt restriction, diuretics (to get rid of excess fluid), digoxin (to strengthen the heart), and other medications. A drug called spironolactone has been found to be a major help in treating congestive heart failure Its beneficial effects are additive to those from ACE inhibitors, another class of drugs commonly relied on in treating heart failure. A pacemaker-like device is also now available to treat heart failure. The implantable device delivers synchronized electrical stimulation to three chambers of the heart, enabling the heart to pump blood more efficiently throughout the body.

Definition of Hypertension

Hypertension: High blood pressure, defined as a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90.

Chronic hypertension is a "silent" condition. Stealthy as a cat, it can cause blood vessel changes in the back of the eye (retina), abnormal thickening of the heart muscle, kidney failure, and brain damage.

For diagnosis, there is no substitute for measurement of blood pressure. Not having your blood pressure checked (or checking it yourself) is an invitation to hypertension.

No specific cause for hypertension is found in 95% of cases.

Hypertension is treated with regular aerobic exercise, weight reduction (if overweight), salt restriction, and medications.


Common Misspellings: hypetension, hypertenson, hypertention, hyppertension, highpertension

Definition of Orthostatic Hypotension

Orthostatic hypotension: A temporary lowering of blood pressure (hypotension) due usually to suddenly standing up (orthostatic). Orthostatic hypotension may be experienced by healthy people -- it is more common in older people -- who rise quickly from a chair, especially after a meal, and have a few seconds of disorientation.

The change in position causes a temporary reduction in blood flow and therefore a shortage of oxygen to the brain. This leads to lightheadedness and, sometimes, a "black out" episode, a loss of consciousness.

Symptoms include dizziness, feeling about to black out, and tunnel vision (all due to insufficient blood flow to the brain). The symptoms are typically worse when standing and improve with lying down.

Tilt-table testing can be used to confirm orthostatic hypotension. Tilt-table testing involves placing the patient on a table with a foot-support. The table is tilted upward and blood pressure and pulse is measured while symptoms are recorded in various positions.

No treatment is needed for orthostatic hypotension. If someone with orthostatic hypotension faints, they will regain consciousness by simply sitting or lying down.

The person is thereafter advised to exercise caution and slow the process of changing positions from lying to sitting to standing. This simple technique can allow the body to adjust to the new position and permit the nerves to circulation of the legs to adjust slower in older person.

Orthostatic hypotension is also called postural hypotension.

Definition of Shock

Shock: In medicine, shock is a critical condition brought on by a sudden drop in blood flow through the body. There is failure of the circulatory system to maintain adequate blood flow. This sharply curtails the delivery of oxygen and nutrients to vital organs. It also compromises the kidney and so curtails the removal of wastes from the body. Shock can be due to a number of different mechanisms including not enough blood volume (hypovolemic shock) and not enough output of blood by the heart (cardiogenic shock). The signs and symptoms of shock include low blood pressure (hypotension), overbreathing (hyperventilation), a weak rapid pulse, cold clammy grayish-bluish (cyanotic) skin, decreased urine flow (oliguria), and mental changes (a sense of great anxiety and foreboding, confusion and, sometimes, combativeness).

Shock is a major medical emergency. It is common after serious injury. Emergency care for shock involves keeping the patient warm and giving fluids by mouth or, preferably, intravenously.

Definition of Arota

Aorta: The largest artery in the body, the aorta arises from the left ventricle of the heart, goes up (ascends) a little ways, bends over (arches), then goes down (descends) through the chest and through the abdomen to where ends by dividing into two arteries called the common iliac arteries that go to the legs.

Anatomically, the aorta is traditionally divided into the ascending aorta, the aortic arch, and the descending aorta. The descending aorta is, in turn, subdivided into the thoracic aorta (that descends within the chest) and the abdominal aorta (that descends within the belly).

The aorta gives off branches that go to the head and neck, the arms, the major organs in the chest and abdomen, and the legs. It serves to supply them all with oxygenated blood. The aorta is the central conduit from the heart to the body.

Definition of Peripheral

Peripheral: Situated away from the center, as opposed to centrally located.

For example, peripheral vision means the type of vision that allows one to see objects that are not in the center of one's visual field.

The word "peripheral" comes from the Greek "peripheria" ("peri-", around or about + "pherein", to bear, carry). An IV (intravenous) catheter is a peripheral line.


Common Misspellings: peripheal, periphial, perpheral

Definition of Vascular

Vascular: Relating to the blood vessels of the body. The blood vessels of the body, as a group, are referred to as the vascular system.

The blood vessels are composed of arteries, veins and capillaries -- arteries that pass oxygen-rich blood to the tissues of the body; veins which return oxygen-depleted blood from the tissues to the lungs for oxygen; and the capillaries that are the tiniest vessels and are between the arteries and veins.

Definition of Congenital heart disease

Congenital heart disease: A malformation of the heart or the large blood vessels near the heart. The term "congenital" speaks only to time, not to causation; it means "born with" or "present at birth."

Congenital heart disease is the most frequent form of major birth defects in newborns affecting close to 1% of newborn babies (8 per 1,000). This figure is an underestimate since it does not include some common problems, namely:

* Patent ductus arteriosus in preterm babies (a temporary condition)
* Bicuspid (two cusps) aortic valve (the aortic valve usually has three cusps or flaps)
* Mitral valve prolapse (drooping of a heart valve)
* Peripheral pulmonary stenosis (narrowing of the lung vessels well away from the heart)

There are a great many types of congenital heart disease. Here is an outline of the major categories of congenital heart disease and some of the more prominent entities within those categories.

Detour defects within the heart: Defects may cause blood to take an abnormal route through the heart, passing directly between the right and left sides of the heart. This occurs when there is a defect in the wall (the septum) that normally separates the right and left sides of the heart. There is "a hole in the heart." The two most common types of septal defect are:

* Atrial septal defect (ASD)
* Ventricular septal defect (VSD)

Less common types of CHD with altered routes of blood flow include:

* Eisenmenger's complex
* Atrioventricular (A-V) canal defect (also called an endocardial cushion defect)

Detour defect outside the heart: Patent ductus arteriosus (PDA) is a special type of a blood routing problem located outside the heart. The ductus arteriosus is a prenatal shunt between the pulmonary artery and the aorta that remains open (patent) after birth, letting blood that should flow through the aorta to the body return to the lungs.

Obstructive defects: A number of types of CHD obstruct blood flow within the heart or the great vessels near it. They do so via a narrowing that partly or completely blocks the flow of blood. The narrowing (a stenosis) can occur in heart valves, arteries or veins. The three most common forms of CHD with obstructed blood flow are:

1. Pulmonary (valvular) stenosis
2. Aortic stenosis
3. Coarctation of the aorta

Less common forms of CHD with obstructed blood flow include:

* Bicuspid aortic valve
* Subaortic stenosis
* Ebstein's anomaly

Cyanotic defects ("blue babies"): Some types of CHD cause cyanosis (bluing). The blood pumped to the body has less-than-normal amounts of oxygen. This results in cyanosis, a bluish discoloration of the skin. Types of cyanotic forms of CHD include:

* Tetralogy of Fallot
* Transposition of the great arteries
* Tricuspid atresia
* Truncus arteriosus
* Total anomalous pulmonary venous return
* Pulmonary atresia

Hypoplastic heart defects: Part of the heart may selectively be underdeveloped or hypoplastic, as in:

* Right heart hypoplasia
* Left heart hypoplasia

Other developmental heart defects: A number of other defects in heart development can occur, such as:

* Single ventricle (There is only one ventricle)
* Double outlet right ventricle (Both the aorta and pulmonary artery emanate from the right ventricle)

Alternative names for congenital heart disease include: congenital heart defect, congenital heart malformation, congenital cardiovascular disease, congenital cardiovascular defect, and congenital cardiovascular malformation.

For a more complete treatment of this topic, see the full-length article on Congenital Heart Disease.


Common Misspellings: congenital heart diease, congenital heart desease