Cardiovascular Diseases - Research Paper Example

? Human anatomy   Topic:  Cardiovascular Diseases Cardiovascular diseases are a collection of diseases affecting the circulatory system which include the heart and the blood vessels – arteries and veins. These diseases may be present at birth (congenital) or may arise in early or adult life. Some of the diseases include; coronary artery disease, periocarditis, arrhythmias, atherosclerosis and congenital heart disease. There has been a steady increase in the incidence and prevalence of cardiovascular diseases both in the developed and developing countries. This has been attributed by various literature sources to the lifestyle changes among the populations as well as diet and genetic factors Treatment of the diseases revolves around managing and monitoring conditions such as high blood pressure and atherosclerosis which may lead to heart attack or may be fatal. Lifestyle changes such as increased physical activity are also encouraged. Cardiovascular diseases Though infectious diseases are still a menace in many parts of the world, in the recent times cardiovascular disease have also risen to the rank of the biggest global killer (Lopez et al., 2006; Dahme et al., 2009). There are a range of cardiovascular diseases affecting the heart and the circulatory system. These diseases may be grouped depending on the organ affected; heart or the blood vessels. Angina pectoris characterized by chest pains due to insufficient supply of oxygen rich blood to the heart. Often this disease is linked to atherosclerosis and coronary artery disease. In the event that the heart’s electrical signals are affected there are irregular heartbeats in conditions called arrhythmias which include atrial fibrillation, atrial flutter and premature atrial complex among others. Risk factors for these diseases are diverse ranging from diabetes mellitus to lifestyle-related factors. When cardiovascular disease affects the cardiac function, it is often referred as cardiomyopathy upon which the contractile aspects of the heart are compromised. There are two forms of cardiac myopathies, dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM). HCM is the hypertrophy of the myocardium without association with diseases which cause myocardial hypertrophy. DCM is defined by a reduction in the cardiac pump function which ultimately progresses to congestive heart failure. Structural defects in heart development diagnosed at birth are collectively referred as congenital heart disease. These include ventricular septal defect, patent ductus arteriosus, pulmonic stenosis among other conditions. The heart valves may also be diseased such as in mistral stenosis, mitral valve regurgitation, mitral valve proplapse and in tricuspid stenosis. The pathological progression (atherosclerosis – chronic degenerative disease of blood vessels) of cardiovascular disease usually commences early in life and it undergoes a long asymptomatic period which is evident in middle or elderly men and women (Berenson et al., 1989). Major risk factors influencing this progression include physical inactivity, unhealthy diet and tobacco consumption as well in diseases; diabetes, dyslipidemia and hypertension. Atherosclerosis is characterized by lipid deposition in the intima, smooth muscles and proliferation of the matrix resulting to a fibrous plaque. Calcification and increased fragility associated with atherosclerosis leads to the rapture of the fibrous plaque exposing thrombogenic material to platelets in circulation. These platelets mediate thrombosis at the site of vessel rupture resulting into vessel occlusion and necrosis. Obstruction of blood vessels following the formation of unstable atherosclerotic plaques on the blood vessel walls are among the features of progression of atherosclerosis. Due to obstruction of blood flow to vital organs, brain and heart, clinical manifestation of cardiovascular diseases such as strokes, myocardial infarction and transient cerebral ischemic attacks begin to occur. Coronary artery disease (CAD) is caused by atherosclerotic occlusion of coronary arteries. In cerebral arteries atherosclerosis causes cerebrovascular disease otherwise called transient ischemic attack/stroke and in the aorta it causes aortic aneurysms. In the development of CAD, as a result of atherosclerosis, the coronary arteries lose their ability to release vasodilation substances which allow an increase in coronary perfusion upon the face of increased oxygen demand by heart tissues. Congestive heart failure accounts for 1% birth defects among life births and making it a leading non-communicable cause of infant mortality (Hoffman and Kaplan, 2002). Various factors which range from environmental to genetic are attributed to expose the risk of congenital heart failure. Environmental factors such as insults during fetal developmental for instance exposure to rubella virus infections and chemical teratogens such as retinoic acid, lithium and even maternal disease such as diabetes may expose the unborn to congenital heart failure (Kohl, 1985; Singh et al., 2000; Hoffman and Kaplan, 2002). Arteriosclerosis, hardening and thickening of arteries, reduces elasticity of arteries and is a complication of atherosclerosis. Lipids plaques are deposited within vessels wall a condition referred as atheroma. Arteriosclerosis may progress and due to continued reduction of arterial lumen and elasticity loss, vessel rupture is imminent. Globally, an estimated 58 million deaths are attributed to cardiovascular diseases, which are equivalent to a combination of deaths due to infectious diseases, maternal mortality and nutritional deficiencies (WHO, 2005). The World Health Organization predicts that between 2006 and 2015, mortality associated with non-communicable diseases will increase by 17 % of which half will be cardiovascular associated (Lopez et al., 2006). Cardiovascular diseases remains as one of the leading cause of death and in the United States, heart diseases and stroke have contributed to nearly 40% of the causes of mortality (CDC, 2005). Apart from being a leading cause of mortality, it has also significantly contributed to disability among the working class and therefore has been a huge economic burden (Elbekai and El-kadi, 2006). Congestive heart failure, a complication of hypertension, valvular heart diseases and idiopathic cardiomyopathy, has witnessed a remarkable rise among Americans with 550, 000 new cases being reported annually (Morbidity and Mortality, 2000). A host of risk factors have been mentioned as to contribute to cardiovascular diseases. Tobacco smoking, high blood pressure, diabetes, obesity and unfavorable lipid concentration have been linked directly or indirectly to this risk (Grau et al., 2010). Atherosclerosis and adverse events associated with cardiovascular disease pathogenesis are usually brought by arterial inflammation and endothelial dysfunction. Therefore, therapeutic agents for the treatment of cardiovascular diseases will strive to reduce vascular inflammation and neutralize atherogenic milieu thereby minimizing the progression of disease. In addition, lifestyle changes will assist in decreasing the risk of cardiovascular diseases. In patients with hypertension lowering blood pressure will in turn lower major events in the progression of cardiovascular diseases. Angiotensin-converting enzyme inhibitors (ACEIs) have been shown as possible candidates in reducing the risk of cardiovascular diseases (Schomig et al., 2008). Dyslipedaemia, ratio of apolipoprotein B to apolipoprotein A-1, accounts for more than 50% of risks attributed to myocardial infarction (Yusuf et al., 2004). Statins are the drug for choice in the treatment of dyslipidemia where they lower levels of low density lipoprotein cholesterol - LDL-C (O'Keefe, et al., 2009). This treatment of dyslipidemia has been shown to affect the progression of atherosclerosis, where atherosclerosis progression has slowed in proportion to LDL-C reduction (O'Keefe, et al., 2009). Another significant risk factor to cardiovascular diseases is tobacco smoking where it has been ranked second only to dyslipidemia as a determinant risk for myocardial infarction (Teo et al., 2006). Diet may also serve as preventative measure for cardiovascular diseases. Omega-3 fatty acids such as docosahexaenoic acid (DHA) and eicosapentaenioc acid (EPA) used as dietary supplements may reduce arrhythmias, lower blood pressure coupled to improving arterial and endothelial function all of which serve to reduce the risks of cardiovascular diseases (Lee et al.,2008). In treatment of cardiovascular diseases, majority of the remedies revolve around lifestyle changes though medications and surgery are often applied in some cases such as stroke and hypertension. Drugs usually applied in treating high blood pressure include beta blockers such as ACEIs and Angiotensin II receptor blocker and calcium channels blockers e.g. vasodilators. However, not all conditions are treatable and others will require proper management and monitoring of any underlying conditions such as in the case of some arrhythmias (atrial fibrillation). In conclusion, though treatment may exist for the treatment of cardiovascular diseases, preventative measures such as change of lifestyle for instance by reducing sedentary lifestyle and cessation of tobacco smoking may serve to reduce the prevalence of these diseases. Whereas in other cases such as high blood pressure and hypertension it will require drug regiments and also close monitoring to avert progression to major cardiovascular disease such as coronary artery diseases. References Berenson, G.S., Srinivasan, S.R., Hunter, S.M., Nicklas, T.A., Freedman, D.S., Shear, C.L. and Webber L.S. (1989). Risk Factors in Early Life as Predictors of Adult Heart Disease: The Bogalusa Heart Study. Am J Med Sci., 298(3):141-151. CDC. (2005). 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Lee, J.H., O'Keefe, J.H., Lavie, C.J., Marchioli, R. and Harris, W.S. (2008). Omega-3 fatty acids for cardioprotection. Mayo Clin Proc. 83(3):324-32. Lopez, A.D., Mathers, C.D., Ezzati, M., Jamison, D.T. and Murray C.J. (2006). Global and regional burden of disease and risk factors, 2001, systematic analysis of population health data. Lancet, 367, 1747-1757. Morbidity and Mortality: (2000). Chart Book on Cardiovascular, Lung, and Blood Diseases. Bethesda, Md: National Institutes of Health: National Heart, Lung, and Blood Institute. O'Keefe, J.H., Carter, M.D. and Carl J. Lavie, C.J. (2009). Primary and Secondary Prevention of Cardiovascular Diseases: A Practical Evidence-Based Approach Mayo Clin Proc. 84(8):741-757. Schomig, A., Mehilli, J., de Waha, A., Seyfarth, M., Pache, J., Kastrati, A. (2008). A meta-analysis of 17 randomized trials of a percutaneous coronary intervention-based strategy in patients with stable coronary artery disease. J Am Coll Cardiol. 52(11):894-904. Singh, M., Shah, G.L. and Singh, K.P. (2000). Teratogenic effects of dilantin on thoraco-abdominal organs of developing chick embryos. Indian J Exp Biol, 38(10):1026-1030. Teo, K.K., Ounpuu, S., Hawken, S., Pandey, M.R., Valentin, V., Hunt, D., Diaz, R., Rashed, W., Freeman, R., Jiang, L., Zhang, X., Yusuf, S. (2006). Tobacco use and risk of myocardial infarction in 52 countries in the INTERHEART study: a case-control study. Lancet., 368(9536):647-658. World Health Organization, (2005). Preventing chronic disease: a vital investment. Geneva. Yusuf, S., Hawken, S., Ounpuu, S., Dans, T., Avezum, A., Lanas, F., McQueen, M., Budaj, A., Pais, P., Varigos, J., Lisheng, L. (2004). Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study. Lancet, 364 (9438):937-952. Read More