What is cardiovascular disease?
Cardiovascular disease refers to a group of diseases that affect the heart and the blood vessels of the body. This group of diseases includes various diseases, most of which are associated with fatty deposits in blood vessels called atherosclerosis.
Cardiovascular diseases(CVD) are the major cause of death worldwide, with 17.9 deaths worldwide, yearly. According to the 2019 statistics, around 48% of the US population suffers from some sort of cardiovascular disease. Around 647,000 Americans die yearly due to cardiovascular diseases, the rate for it being 1 in 4 deaths. According to the CDC, every 40 seconds an American suffers from a heart attack.
Cardiovascular diseases are an extremely important diagnosis and require immediate treatment.
Types of cardiovascular disease
Cardiovascular diseases are of four major types, as follows:
- Aortic Diseases
- Heart Attack or Myocardial Infarction (MI)
- Strokes or Transient Ischemic Attack (TIA)
- Peripheral Artery Diseases (PAD)
Cardiovascular diseases can also be divided into diseases of the heart and diseases of the vessels, such as:
A. Cardiac Diseases
- Rheumatic Heart Disease
- Valvular Heart Disease
- Heart Failure (HF)
- Congenital Diseases
- Carditis (Endocarditis, Myocarditis)
- Vascular Diseases
- Coronary Artery Diseases (CAD)
- Peripheral Artery Diseases (PAD)
- Aortic Aneurysms
- Renal artery disorders (stenosis or narrowing of the lumen)
- Cerebrovascular diseases
What are the risk factors of cardiovascular disease?
There are many risk factors of cardiovascular diseases, such as age, ethnic background, lifestyle choices, smoking, alcohol, and so on. Although some of these risk factors are not in an individual’s control, most of the risk factors for cardiovascular diseases are modifiable resulting in a decreased risk. The risk factors are mentioned below:
1. Age: It is a very important and immutable risk factor for cardiac disease, with risks tripling every decade. There are many hypotheses for why age has such a great effect on the development of CVD. One of them is that cholesterol levels increase with age, and since serum cholesterol levels play an important role in the development of fatty plaques, increased age would result in increased cholesterol and in turn, a high number of plaques. Furthermore, age has a negative effect on the structural integrity of vessels, resulting in increased vascular damage with minimal insults at increased ages.
2. Genetics: Offsprings of parents with cardiovascular diseases have a three-time higher risk of developing some sort of cardiovascular disease themselves compared to those with healthy parents. Many studies have shown the involvement of single nucleotide polymorphisms in the development of CVD but the mechanism is not clearly understood yet.
3. Sex: Postmenopausal women and men have equal risks of developing one of the cardiovascular diseases. However, premenopausal women have a lower risk than men. There is approximately 40% of the variation between the genders and development of CVD, according to a study by the World Health Organization (WHO).
The less risk faced by premenopausal women can be associated with Estrogen levels. Estrogen plays an important role in the improvement of endothelial cell function, glucose metabolism, and increasing HDL and decreasing LDL. And since Estrogen levels decrease after menopause, postmenopausal women face the same amount of risk as men.
4. Smoking: Around 10% of all cardiovascular diseases can be associated with tobacco smoking. However, it is important to note that those who quit smoking before the age of 30 reduce the risk of developing cardiovascular disease significantly.
5. Sedentary Lifestyle: Decreased physical activity is associated with increased risk of cardiovascular diseases as it is associated with increased obesity, high glucose levels, and higher cholesterol. Living a sedentary lifestyle increases the risk of developing various diseases.
6. Diet: Insufficient intake of healthy fats, fruits, and vegetables has been linked to approximately 1.7 million deaths, according to the World Health Organization. Diet high in trans fats results in increased obesity and serum cholesterol levels which overall can negatively impact cardiovascular health. Removal of trans fat has been heavily advocated since they don’t just affect the cholesterol levels but also the proinflammatory cytokines, resulting in an exaggerated negative response.
7. Alcohol: The relation between alcohol consumption and cardiovascular disease development is complicated, as the whole thing depends on the level of consumption. Higher levels of consumption are definitely associated with cardiovascular disease development. But lower or moderate levels of consumption are associated with a reduced risk of cardiac disease. Further studies need to be performed for a better understanding of the mechanisms and the causal-effect relation.
8. Air Pollution: Particulate matter is associate with the development of cardiovascular disease although the exact mechanism is yet to be understood.
9. Sleep: Sleep disorders affecting sleep or breathing during sleep like insomnia and sleep apnea, respectively can result in an increased cardiac metabolic rate and an overall increase in the risk of cardiac disease.
10. Mental Health Disorders: Diseases affecting the mental health of an individual like depression, or stress, whether occupational or trauma-induced, can cause serious damage to cardiovascular health, resulting in an overall decreased stability in cardiovascular health.
Pathophysiology of cardiac diseases
Cardiovascular diseases are associated with plaque buildup known as atherosclerosis, in the vessels, namely the aorta and the coronary arteries around the heart. Scientists have found that this atherosclerosis that acts as a major precursor to heart disease actually develops at a very young age, around 5-9 years.
Furthermore, cardiovascular diseases can also develop from pre-existing conditions like diabetes mellitus, chronic kidney disease/Renal failure, and hypercholesterolemia.
Can cardiovascular diseases be prevented?
It is important for all those at risk for cardiovascular diseases to try and reduce the modifiable risks by eating healthy, balanced diets, and exercising regularly, living an active life. Individuals at risk and everyone else might consider the removal of trans and saturated fats from their diet and include more fresh fruits and vegetables. Most doctors usually recommend the ‘Mediterranean diet’ to their patients. The recommended amount of exercise per week is 150 minutes of moderate exercise.
Smokers must quit smoking completely, whereas alcohol users can reduce their intake to a low consumption level.
It is also important to reduce the psychological stress experienced by an individual, especially those with a family history of cardiovascular disease. Stress can also lead to increased blood pressure which in the long run can lead to heart failure and aneurysms.
Hence it is important to reduce stress by regular meditation and also, to reduce blood pressure.
Patients who suffer from high serum cholesterol levels, diabetes, kidney disease, or hypertension must also strictly abide by their doctors’ recommendations. Furthermore, they must take their medication on time and the appropriate dose to prevent the progression of these co-morbidities into cardiovascular diseases.
How are cardiovascular diseases treated?
Initial treatments of cardiovascular disease are dependant on lifestyle changes and dietary modifications. Depending on the type of CVD, treatments differ. However, secondary management options include ACE inhibitors, aspirin, beta-blockers, and statins.
These drugs target different mechanisms of action, aiming to reduce the risk of a second cardiac event. ACE inhibitors are vasodilating drugs that relax blood vessels and decrease blood pressure. They are used in cases of hypertension and heart failure.
Aspirin is a painkiller that can also irreversibly interfere with blood clotting, preventing blood clots in the bloodstream. It is usually given shortly after a heart attack and acts as a blood thinner.
Beta-blockers block beta-adrenergic receptors causing your body to lower blood pressure and decrease the heart rate. It is usually used for the treatment of arrhythmias and as preventive medicine for heart attacks.
Statins reduce the production of cholesterol in the liver resulting in an overall decrease in serum cholesterol levels. They are the most common lipid-lowering drugs and are usually prescribed for hypercholesterolemia, especially if associated with cardiovascular disease.
Can cardiovascular diseases be screened?
Cardiovascular diseases are the leading cause of death worldwide. This is why individuals at risk must undergo regular screening to ensure proper health. Some of the screening methods are mentioned below:
- Blood Pressure measurement: Since hypertension can lead to cardiovascular diseases, measuring blood pressure regularly can be beneficial. If the blood pressure is normal on the initial evaluation, follow-up must be done every 2 years. However, if someone suffers from hypertension, they must have their blood pressure measure more frequently.
- Serum Cholesterol levels: It is important to start measuring total cholesterol starting from the age of 20, if at low risk for CVD. The cholesterol measured is the total cholesterol and must be under the value of 200 for it to be healthy. HDL levels should be high and LDL levels should be low. The test should be repeated every 2-3 years for low-risk individuals.
- Body Weight and Body-Mass Index must be measure at every regular healthcare checkup. It is important to note that although these values can give an idea about obesity, BMI is not the most accurate measurement of obesity.
- Blood glucose: This should be measured to check for diabetes or diabetes-associated CVD, at least every 3 years.
- General questions about health and lifestyle, including smoking and alcohol consumption.
Cardiovascular diseases mostly develop due to atherosclerotic plaques which start developing from a young age. In the Pathobiological Determinants of Atherosclerosis in Youth (PDAY), scientists found that intimal lesions develop from youth. This is exactly why it is important for everyone to take the best care of their health from a very young age by eating right and exercising daily. Furthermore, the youth today is under a lot of stress, which can be an added risk for CVD development. Hence it is important to raise awareness about the causal-effect relation between stress and CVD so that more people can reduce stress and decrease the risk of CVD development.
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