4.1 Overview This chapter provides some insight into pulse wave analysis and its relation to arterial diseases. The shape of the arterial pulse wave is an augmentation of the forward traveling wave with the reflected wave. The amount of wave reflection is dependent on the arterial wall properties such as arterial stiffness and is expressed in terms of Augmentation Index. This approach has been studied extensively using various measuring techniques, all of which have respective advantages and disadvantages. The purpose of PWA can be seen in the section describing the medical conditions that affect the wave shape. The discussion is included to assist the reader in understanding the purpose of pulse wave analysis. 4.2 Description of Pulse Wave Shape O’Rourke [13] describes the pulse wave shape as: “A sharp upstroke, straight rise to the first systolic peak, and near-exponential pressure decay in the late diastole.” Arteries are compliant structures, which buffer the pressure change resulting from the pumping action of the heart. The arteries function by expanding and absorbing energy during systole (contraction of the cardiac muscle) and release this energy by recoiling during diastole (relaxation of the cardiac muscle). This function produces a smooth pulse wave comprising a sharp rise and gradual decay of the wave as seen in Figure 5. As the arteries age, they become less compliant and do not buffer the pressure change to the full extent. This results in an increase in systolic pressure and a decrease in diastolic pressure. Figure 5: Example of pulse wave shape 4.3 Wave Reflection In an arterial system, the input impedance of the vessel varies with changes in the vessel’s size and properties. For compliant arteries, whic... ... middle of paper ... ...essure in the central arteries . • Hypertension: Hypertension is an abnormal increase in the systolic,diastolic or mean arterial pressure, or all three. This is due to increased arterial stiffness and can be monitored using PWA • Diabetes Mellitus: Diabetes mellitus (Type I Diabetes and Type II Diabetes) has been associated with an increase in arterial stiffness . O’Rourke’s studies showed that PWA does not aid in the diagnostics of diabetes mellitus. Further research by Cruickshank showed that PWV is a powerful independent predictor of mortality for diabetes. • Chronic Renal Failure: Savage et al conducted an investigation into the reproducibility of PWA on patients with Chronic Renal Failure (CRF). Their study concluded that indices of arterial stiffness, such as AiX and Time to Reflection (TR), which is determined by PWA, can assist in the assessment of CRF
Blood pressure is measured by two pressures; the systolic and diastolic. The systolic pressure, the top number, is the pressure in the arteries when the heart contracts. The diastolic pressure, the bottom number, measures the pressure between heartbeats. A normal blood pressure is when the systolic pressure is less than 120mmHg and Diastolic pressure is less than 80mmHg. Hypertension is diagnosed when the systolic pressure is greater than 140mmHg and the diastolic pressure is greater than 90mmHg. The physician may also ask about medical history, family history, life style habits, and medication use that could also contribute to hypertension
7. Sae Young, J., Heffernan, K., Fernhall, B., & Yoon-Ho, C. (2012). Cardiorespiratory Fitness and Carotid Artery Intima Media Thickness in Men With Type 2 Diabetes. Journal Of Physical Activity & Health, 9(4), 549-553.
Coronary heart disease is defined by the hardening of the epicardial coronary arteries. The buildup of plaque in the arteries slowly narrows the coronary artery lumen. In order to better understand the physiology of the disease, it is important to first know the basic anatomy of the human heart. The aorta, located in the superior region of the heart, branches off into two main coronary blood vessels, otherwise known as arteries. The arteries are located on the left and right side of the heart and span its surface. They subsequently branch off into smaller arteries which supply oxygen-rich blood to the entire heart (Texas Heart Institute, 2013). Therefore, the narrowing of these arteries due to plaque buildup significantly impairs blood flow throughout the heart.
The heart serves as a powerful function in the human body through two main jobs. It pumps oxygen-rich blood throughout the body and “blood vessels called coronary arteries that carry oxygenated blood straight into the heart muscle” (Katzenstein and Pinã, 2). There are four chambers and valves inside the heart that “help regulate the flow of blood as it travels through the heart’s chambers and out to the lungs and body” (Katzenstein Pinã, 2). Within the heart there is the upper chamber known as the atrium (atria) and the lower chamber known as the ventricles. “The atrium receive blood from the lu...
The cardiovascular system is powered by the body’s hardest-working organ, the heart. Being roughly the size of an adult males clenched fist, it contracts and relaxes about 70 to 80 times per minute pushing
Through the examination, it was evident that the tissues within the heart varied significantly in thickness and size. We were able to insert our fingers through the blood vessels. By doing so, we were able to identify whether the vessel was an artery or vein. The artery of the heart was much thicker and bigger than the veins, this was because the arteries were responsible for transferring oxygenated blood from the heart to the rest of the body, which requires great strength. The heart itself created pressure differences that helped blood to flow from high to low pressure. The artery pumped blood at high pressure so that it could travel to all the body parts. The thick walls of the arteries were needed to withstand the high pressure coming from the heart. The blood returned to the heart through veins, and because of the lower pressure, the walls of the veins were
During each heartbeat, the heart muscle contracts to push blood around the body. When the left ventricle contracts blood is forced into the aorta and its branches become under pressure. This pressure provides the driving force that makes blood flow through arteries. There are two type of pressure. Systolic blood pressure is the blood pressure when the heart is contracting; normal rate of systolic blood pressure is about 120 mmHg. Diastolic blood pressure is the blood pressure when the heart is relaxing; normal rate of diastolic pressure is about 80 mmHg (Smith, 2003). In addition, the walls of the arteries contain muscle and elastic fibers. Each time that the heart beats and discharges blood into the arterial system, these fibers stretch to accommoda...
Weakness/ Gap The outcomes of the literature reviews of the use of the HBPM might not be applicable to people with complicated hypertension. Due to the seriousness of their illness, they could be unable to participate in the intervention groups in self-measurement blood pressure monitoring at home. Therefore, it affects the reliability and validity of these findings from previous research (Uhlig, Patel, Ip, & Kitsios, 2013). Numerous studies have presented specific recommendations regarding hypertension management and treatment, which are valid and reliable.
Foëx, P., et al; (2004). Hypertension: pathophysiology and treatment. Arterial hypertension is an important reason of morbidity and mortality because of its connection with coronary heart disease, cerebro-vascular disease and renal disease. The degree of target organ involvement (i.e. heart, kidneys and brain) determines results. Studies in North America have shown that hypertension is a major reason of 500000 strokes (250 000 deaths) and 1000 000 myocardial imperfections (500000 deaths) per year. Continuous National survey reveals that hypertension is often not detected and, when diagnosed, is often improperly treated. Among hypertensive patients, only 25% cases are well handled. This is true for isolated systolic hypertension. Yet the occurrence
Blood pressure is a measurement of how forcefully blood presses against the walls of arteries throughout the body, the higher this pressure, the greater the strain on the heart and vital organs (Nordqvist, 2009).This pressure increase is often a consequence of narrowed diameter of blood vessels and increasing viscosity of the blood (Schnitzer, 2000).
Blood pressure (BP) refers to the amount of force that is exerted upon arterial walls via the pumping of blood from the heart.1 Blood pressure can either be categorized as hypotension (low BP), normotension (Normal BP) or most important clinically as hypertension (High BP). Hypertension is a multi-factorial disease that is defined by having a systolic blood pressure (SBP) of 140mmHg and/or a diastolic blood pressure (DBP) of greater than 90mmHG based on the average of two or more readings after an initial screening.2
The most common and dangerous determinant of vascular disease is arteriosclerosis, literally meaning “hardening of the heart.” It is a general term for disorders whose similar effects to the arterial walls are its thickening and its loss of elasticity. Arteriosclerosis may occur as three types namely, Monckeberg’s medial calcific sclerosis, the calcification of the media of muscular arteries; arteriolosclerosis, the hyaline thickening of small arteries and arterioles; and the most common atherosclerosis, the formation of atheromas—a thickening of the arterial wall that is brought upon by cholesterol laden plaque and the amassing of scar tissue.
The pathogenesis of hypertension is multifactorial and highly complex. There are several influential factors that control blood pressure (BP) for adequate tissue perfusion, such as vascular reactivity, circulating blood volume, blood viscosity, cardiac output, blood vessel elasticity, and neural stimulation. Increased peripheral resistance, vascular rigidity, and vascular responsiveness to stimuli are significant to the pathophysiology of hypertension. Sodium has a primary effect on blood pressure leading to excess circulating volume, affecting hypertrophy, contractility, and vascular resistance (Buttaro, Trybulski, Bailey, Sandberg-Cook, 2011).
Hypertension is a medical condition wherein the blood pressure stays higher than 140 over 90 mmHg.* When blood pressure remains elevated for an unknown cause, it is called primary (also known as essential or idiopathic) hypertension. On the other hand, high blood pressure as a result of another complication such as tumor, endocrine or kidney diseases it is called secondary hypertension.* Risk factors which are likely to contribute to high blood pressure include age (more prone to people age 60 years and above), weight/size (obesity), sex (men are mostly diagnosed with hypertension) and lifestyle factors such as excessive alcohol consumption, constant tobacco (cigarette) smoking, low physical activity, having a salt-rich diet and genes (family history of hypertension). Unrestrained and prolonged hypertension increases mortality and morbidity.*
Complications concerning one's’ heart and blood pressure plague numerous people around the world. Prevention of such complications is critical when working toward an overall healthier world.