Overview Of Systolic Function And Dysfunction
Argosy University Twin Cities
ECH215-Cardiovascular Principles II
Systolic Function and Dysfunction In this paper I will discuss systolic function and systolic dysfunction. I will first define systolic function from physical as well as from physiological aspects: from mechanical and electrical systole, to preload and afterload. From there I will describe four modalities in which systolic function is measured and assessed. This will also include any formulas used to determine needed volumes and percentages. Lastly I will cover three causes of systolic dysfunction. Systolic function in its simplest terms is, how well the ventricle contracts. However, …show more content…
“Stroke volume is a measurement of how much blood the heart pumps out of a ventricle with each beat” (McMahon, 2015). There are two formulas to calculate stroke volume, one is – end diastolic volume minus end systolic volume of the left ventricle obtained in the apical four chamber view, the other is – the cross sectional surface area of the left ventricular out-flow tract multiplied by the velocity time integral. “The LVOT velocity time intergral (VTI) provides information regarding blood velocity across the time period of systole and is in the units of cm. Typical values are close to 2 cm.”(Qasim and Raina, n.d. para 3). Another measurement used to evaluate systolic function is cardiac output. Cardiac output is defined as the amount of blood ejected per minute from the heart, it is measured in liters per minute. Cardiac output in calculated by multiplying stroke volume by the patient’s heart rate. The third modality to measure systolic function is cardiac index. Cardiac index is a formula that divides the patient’s cardiac output by their body surface area. This shows the relationship between cardiac output and body surface area. The last measurement/formula that assesses systolic function is ejection fraction. Ejection fraction is defined as the percentage of blood that is ejected from the heart. The ejection fraction can be formulated in …show more content…
“Myocarditis is an inflammation of the myocardium, the middle layer of the heart wall. Myocarditis is usually caused by a viral infection. Signs and symptoms of myocarditis include chest pain, heart failure and abnormal heart rhythms.”(Mayo Clinic, 2012). Another cause of systolic dysfunction is valvular stenosis. Valvular stenosis is defined as a thickening or blockage to one or possibly more heart valve. In example, if a patient has aortic valve stenosis, their left ventricle would have great difficulty pumping blood efficiently. One other cause of systolic dysfunction is coronary heart disease or CHD. This cause of systolic dysfunction is from plaque that builds up in the coronary arteries and reduces blood flow to the heart, this is called atheroschlerosis.
Through the research process for this paper I feel that I have a greater understanding of systolic function and its importance. My time in echo lab has given me the skills for measuring and assessing systolic function: from stroke volume to ejection fraction. Most importantly, I also obtained the knowledge to recognize systolic dysfunction, as well as a number of diseases that cause systolic dysfunction. Systolic function in its simplest terms is, how well the ventricle contracts. However, many necessary elements come into play when it comes to fulfilling such a life dependent