Cardiovascular disease

Cardiovascular disease refers to the class of diseases that involve the heart or blood vessels (arteries and veins). While the term technically refers to any disease that affects the cardiovascular system, it is usually used to refer to those related to atherosclerosis (arterial disease). These conditions have similar causes, mechanisms, and treatments. In practice, cardiovascular disease is treated by cardiologists, thoracic surgeons, vascular surgeons, neurologists, and interventional radiologists, depending on the organ system that is being treated. There is considerable overlap in the specialties, and it is common for certain procedures to be performed by different types of specialists in the same hospital.

Most Western countries face high and increasing rates of cardiovascular disease. Each year, heart disease kills more Americans than cancer.^[1] Diseases of the heart alone caused 30% of all deaths, with other diseases of the cardiovascular system causing substantial further death and disability. Up until the year 2005, it was the number 1 cause of death and disability in the United States and most European countries. A large histological study (PDAY) showed vascular injury accumulates from adolescence, making primary prevention efforts necessary from childhood.^[2][3]

By the time that heart problems are detected, the underlying cause (atherosclerosis) is usually quite advanced, having progressed for decades. There is therefore increased emphasis on preventing atherosclerosis by modifying risk factors, such as healthy eating, exercise and avoidance of smoking.

Additional recommended knowledge

Essential Laboratory Skills Guide

Daily Sensitivity Test

Weighing the right way

Risk factors

There are many risk factors which associate with (but are not all causes of) various forms of cardiovascular disease. These include the following:

• Non-modifiable Risk Factors
  • Age
  • Gender, men under age 64 are much more likely to die of coronary heart disease than women, although the gender difference declines with age.^[4] (The gender difference is less pronounced in blacks than in whites, but it is still significant ^[5])
  • Genetic factors/Family history of cardiovascular disease
  • Race (or ethnicity), Studies show that African Americans are twice as likely to develop high blood pressure than caucasians.
  • Environment, your chances can increase beacuse of areas with a lot of smog or other form of air pollution, or from someone else's cigar, pipe, or cigarette smoke.

• Modifiable Risk Factors
  • Tobacco smoking
  • Insulin resistance & Diabetes mellitus
  • Hypercholesterolemia (elevated cholesterol levels) and abnormal lipoprotein particle profile (cholesterol subtypes)
  • Obesity, especially central or male-type obesity; apart from being linked to diabetes, this form of obesity independently increases cardiovascular risk, presumedly by inducing an inflammatory and procoagulant state
  • High blood pressure
  • Sleep deprivation
  • Elevated heart rate^[6]
  • Physical inactivity/Sedentary lifestyle
  • Absence of key nutritional elements, such as omega-3 fatty acids and polyphenol antioxidants
  • Exposure to high levels of environmental noise
  • Stress
  • Rocky Relationships^[7]
  • Depression
  • Periodontal disease

Although men have a higher rate of cardiovascular disease than women, it is also the number one health problem for women in industrialized countries. After menopause, the risk for women approaches that of men. Hormone replacement therapy alleviates a number of post-menopausal problems, but appears to increase the risk of cardiovascular disease.

Biomarkers

Some biomarkers are thought to offer a more detailed risk of cardiovascular disease. However, the clinical value of these biomarkers is questionable.^[8] Currently, biomarkers which may reflect a higher risk of cardiovascular disease include:

• Higher fibrinogen and PAI-1 blood concentrations
• Elevated homocysteine, or even upper half of normal
• Elevated blood levels of asymmetric dimethylarginine
• High inflammation as measured by C-reactive protein
• Elevated blood levels of B-type natriuretic peptide (BNP) ^[9]

Prevention

Attempts to prevent cardiovascular disease are more effective when they remove and prevent causes, and they often take the form of modifying risk factors. Some factors, such as gender, age, and family history, cannot be modified. Smoking cessation (or abstinence) is one of the most effective and easily modifiable changes. Regular cardiovascular exercise (aerobic exercise) complements the healthful eating habits. According to the American Heart Association, build up of plaque on the arteries (atherosclerosis), partly as a result of high cholesterol and fat diet, is a leading cause for cardiovascular diseases. The combination of healthy diet and exercise is a means to improve serum cholesterol levels and reduce risks of cardiovascular diseases; if not, a physician may prescribe "cholesterol-lowering" drugs, such as the statins. These medications have additional protective benefits aside from their lipoprotein profile improvement. Aspirin may also be prescribed, as it has been shown to decrease the clot formation that may lead to myocardial infarctions and strokes; it is routinely prescribed for patients with one or more cardiovascular risk factors.

One possible way to decrease risk of cardiovascular disease is keep your total cholesterol below 150. In the Framingham Heart Study, those with total cholesterol below 150 only very rarely got coronary heart disease.

A magnesium deficiency, or lower levels of magnesium, can contribute to heart disease and a healthy diet that contains adequate magnesium may prevent heart disease.^[10] Magnesium can be used to enhance long term treatment, so it may be effective in long term prevention.^[11] Excess calcium may contribute to a buildup of calcium in the veins. Excess calcium can cause a magnesium deficiency, and magnesium can reduce excess calcium.

Foods for Cardiovascular Health

Research has shown that a diet that includes dark chocolate, almonds, fish, wine, fruits, vegetables, and garlic can increase life expectancy and decrease your risk for cardiovascular disease.^[12]

Eating oily fish at least twice a week may help reduce the risk of sudden death and arrhythmias. A 2005 review of 97 clinical trials by Studer et al. noted that omega-3 fats gave lower risk ratios than did statins.^[13] Olive oil is said to have benefits. Studies of individual heart cells showed that fatty acids blocked excessive sodium and calcium currents in the heart, which could otherwise cause dangerous, unpredictable changes in its rhythm.

Cardiovascular disease and salt

There is evidence from one large unblinded randomised controlled trial of more than 3000 patients that reducing the amount of sodium in the diet reduced the risk of cardiovascular events by more than 25%.^[14] This re-affirms evidence from the Intersalt study published in 1996, that high levels of dietary salt are harmful;^[15] these results were at the time heavily disputed by the Salt Institute (the salt producers' trade organisation).^[16]

Awareness

Atherosclerosis is a process that develops over decades and is often silent until an acute event (heart attack) develops in later life. Population based studies in the youth show that the precursors of heart disease start in adolescence. The process of atherosclerosis evolves over decades, and begins as early as childhood. The Pathobiological Determinants of Atherosclerosis in Youth Study demonstrated that intimal lesions appear in all the aortas and more than half of the right coronary arteries of youths aged 15–19 years. However, most adolescents are more concerned about other risks such as HIV, accidents, and cancer than cardiovascular disease.^[17] This is extremely important considering that 1 in 3 people will die from complications attributable to atherosclerosis. In order to stem the tide of cardiovascular disease, primary prevention is needed. Primary prevention starts with education and awareness that cardiovascular disease poses the greatest threat and measures to prevent or reverse this disease must be taken.

Treatment

Treatment of cardiovascular disease depends on the specific form of the disease in each patient, but effective treatment always includes preventive lifestyle changes discussed above. Medications, such as blood pressure reducing medications, aspirin and the statin cholesterol-lowering drugs may be helpful. In some circumstances, surgery or angioplasty may be warranted to reopen, repair, or replace damaged blood vessels.

Types of Cardiovascular Diseases

Aneurysms

Angina

Arrhythmia

Atherosclerosis

Cardiomyopathy

Cerebrovascular Accident (Stroke)

Cerebrovascular Disease

Congenital Heart Disease

Congestive Heart Failure

Myocarditis

Valve Disease

Coronary Artery Disease

Dilated cardiomyopathy

Diastolic Dysfunction

Endocarditis

High Blood Pressure (Hypertension)

Hypertrophic Cardiomyopathy

Mitral valve prolapse

Myocardial Infarction (Heart Attack)

Venous Thromboembolism

Research

The causes, prevention, and/or treatment of all forms of cardiovascular disease are active fields of biomedical research, with hundreds of scientific studies being published on a weekly basis.

A fairly recent emphasis is on the link between low-grade inflammation that hallmarks atherosclerosis and its possible interventions. C-reactive protein (CRP) is an inflammatory marker that may be present in increased levels in the blood in patients at risk for cardiovascular disease. Its exact role in predicting disease is the subject of debate.

Some areas currently being researched include possible links between infection with Chlamydophila pneumoniae and coronary artery disease. The Chlamydia link has become less plausible with the absence of improvement after antibiotic use.^[18]

References