Heart Disease: Definition, Causes, Research

Heart disease is an umbrella term for any type of disorder that affects the heart. Heart disease means the same as cardiac disease but not cardiovascular disease. Cardiovascular disease refers to disorders of the blood vessels and heart, while heart disease refers to just the heart.

According to WHO (World Health Organization) and the CDC, heart disease is the leading cause of death in the UK, USA, Canada and Australia. The number of US adults diagnosed with heart disease stands at 26.6 million (11.3% of adult population).1

23.5% of all deaths in the USA today are caused by heart disease.2

We take a look at some of the most common examples of heart disease below.

Angina

Also known as angina pectoris, angina occurs when an area of heart muscle does not get enough oxygen. The patient experiences chest discomfort, tightness or pain. Angina is not technically a disease, but rather a symptom of coronary artery disease. Lack of oxygen to the heart muscle is usually caused by the narrowing of the coronary arteries because of plaque accumulation (atherosclerosis).

Arrhythmia

Arrhythmia is an irregular heartbeat.

• Tachycardia is when the heart beats too fast
• Bradycardia is when the heart beats too slowly
• Premature contraction is when the heart beats too early
• Fibrillation is when the heart beat is irregular

Arrhythmias are problems with heart-rhythm. They happen when the heart's electrical impulses that coordinate heartbeats do not work properly, making the heart beat in a way it should not, either too fast, slowly or erratically.

Irregular heartbeats are common, we all experience them. They feel like a fluttering or a racing heart. However, when they veer too far from normal heartbeat or occur because of a damaged or weak heart, they need to be taken more seriously and treated. Irregular heartbeats can become fatal.

Congenital heart disease

This is a general term for some birth defects that affect how the heart works. Congenital means you are born with it. In the UK it is estimated that 1 in every 1,000 babies are born with some kind of congenital heart disease. Examples include:

• Septal defects - there is a hole between the two chambers of the heart. This condition is sometimes called hole in the heart.
• Obstruction defects - the flow of blood through various chambers of the heart is partially or even totally blocked
• Cyanotic heart disease - not enough oxygen is pumped around the body because there is a defect (or some defects) in the heart.

Coronary artery disease

The coronary arteries, which supply the heart with nutrients, oxygen and blood become diseased or damaged, usually because of plaque deposits (cholesterol-containing deposits). Plaque accumulation narrows the coronary arteries and the heart gets less oxygen.

Dilated cardiomyopathy

In this disorder the heart chambers become dilated because the heart muscle has become weak and cannot pump blood properly. The most common reason is not enough oxygen reaching the heart muscle (ischemia) due to coronary artery disease. Usually the left ventricle is affected.

Myocardial infarction

Also known as heart attack, cardiac infarction and coronary thrombosis. Interrupted blood flow (lack of oxygen) damages or destroys part of the heart muscle. This is usually caused by a blood clot that develops in one of the coronary arteries (blood vessels that supply the heart with blood). It can also occur if an artery suddenly narrows (spasm).

Heart failure

Also known as congestive heart failure. The heart does not pump blood around the body efficiently. The left or right side of the body might be affected; sometimes both sides are. Coronary artery disease or hypertension (high blood pressure) can over time leave the heart too stiff or weak to fill and pump properly.

Hypertrophic cardiomyopathy

A genetic disorder in which the wall of the left ventricle becomes thick, making it harder for blood to leave the heart. The heart has to work harder to pump blood. This is the leading cause of sudden death in athletes. A father or mother with hypertrophic cardiomyopathy has a 50% chance of passing the disorder onto their children.

Mitral regurgitation

Also known as mitral valve regurgitation, mitral insufficiency or mitral incompetence occurs when the mitral valve in the heart does not close tightly enough, allowing blood to flow back into the heart when it shouldn't. Blood cannot move through the heart or the body efficiently. Patients feel tired and out of breath.

Mitral valve prolapse

The valve between the left atrium and left ventricle does not fully close, it prolapses (bulges) upwards, or back into the atrium. In the majority of cases the condition is not life-threatening and no treatment is required. Some patients, especially if the condition is marked by mitral regurgitation, may require treatment.

Pulmonary stenosis

It is hard for the heart to pump blood from the right ventricle into the pulmonary article because the pulmonary valve is too tight; the right ventricle has to do more work to overcome the obstruction. A baby with severe stenosis can become cyanotic (turn blue). Older kids generally have no symptoms. If pressure in the right ventricle is too high treatment is required. Balloon valvuloplasty or open heart surgery may be needed if there is an obstruction.

Recent developments on heart disease from MNT news

Scientists uncover bacterial mechanism that links gum disease to heart disease

A new study clarifies the microbiology underlying the well-established link between gum diseaseand heart disease by identifying the effect of a bacterium common to both conditions.

Digital mammography can help predict heart disease

Mammography could help predict heart disease in women by detecting signs of calcium in the arteries of the breast. This could make early treatment possible, with potential benefits, especially for young women.

Apple- or pear-shaped? Your answer may affect your heart disease risk

New research being presented at the American College of Cardiology 2016 Scientific Session in Chicago, IL, adds to the evidence that where you carry your weight is more likely than weight or body mass index to tell you whether you will have heart disease.

'Good' cholesterol may not always protect against heart disease

High levels of "good cholesterol," or high-density lipoprotein, are unlikely to protect people from heart disease if their bloodstream also contains high levels of a newly identified biomarker of inflammation in the arteries.

How can red wine help the gut microbiome to prevent heart disease?

Red wine contains a compound called resveratrol, which could reduce the risk of heart disease by changing the gut microbiome, according to research published in mBio.