Borek Case Study Heart - Grade: A PDF

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Case study about the heart for AP II...

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Case Study: Crimes of the Heart Case Study 1 - Crimes of the Heart! AP II T/Th 8 am! Dr. Baker spends a long time listening to (auscultating) Caleb’s heart. a. Where on the thoracic surface do you auscultate to the tricuspid, mitral (bicuspid), pulmonary, and aortic valves? Auscultation of Tricuspid is 4rth intercostal space on the anatomical left of the chest (lower left sternal border). Mitral valve is 5th intercostal space, medial to the midclavicular line (left). Pulmonary is on the upper sternal border and the 2nd intercostal space. The aortic valve is 2nd intercostal space on the right upper sternal border. " b. Where do you think would be the best place to auscultate Caleb’s abnormal heart sound? Caleb’s defect would be the most pronounced on the right ventricle side of the septum, (near the tricuspid) as blood would be flowing in the wrong direction (from left ventricle to right ventricle) and there would be an unusual sound caused by the blood being pushed to the right ventricle from the left ventricle during atrial systole ! Caleb’s abnormal heart sounds that tipped the doctor off to a problem. " a. Name the normal sounds of the heart and indicate what causes these sounds. " “Lub,” or S1, is caused by tricuspid and bicuspid (AV valves) closing at the start of ventricular systole. “Dub,” or S2, is caused by the closure of the semilunar valves at the end of systole." b. In relation to the normal heart sounds, when would you expect to hear the abnormal sound Dr. Baker heard? During Systole: Ventricular Septal Defects produce a Holosystolic#(pan-systolic murmur) between S1 and S2 because a left to right blood flow is continued throughout ventricular systole. The blood is pushed into the right ventricle causing a distinct murmur between normal heart sounds.! The defect in Caleb’s heart allows blood to mix between the two ventricular chambers. " a. Due to this defect would you expect the blood to move from left-to-right ventricle or right-to-left ventricle during systole? ! The blood would flow from left to right during ventricular systole as the heart muscle squeezes up from the apex. The contraction would push the blood up and over to the right ventricle as the left ventricle produces the strongest contraction and has the largest myocardium layer (Mckinney et al., 2012)." b. Based on your understanding of blood pressure and resistance in the heart and great vessels, explain your answer to question 3a. " The blood in the heart will follow the rules of pressure. It will move down its pressure gradient and into the right ventricle. The right ventricle has lower pressure due to less afterload and the blood will be drawn there by the pressure difference and lack of resistance from pulmonary vessels.! When an echocardiogram is performed, the technician color-codes oxygenated blood (red) and deoxygenated blood (blue)." a. In a healthy baby, what color would the blood be within the right and left ventricles, respectively? ! The right ventricle contains blood draining from the superior and inferior vena cavae after nourishing the body’s tissues (it’s deoxygenated) and therefore would be blue. The left ventricle contains blood that has just returned from the lungs and is oxygenated. The blood in the left ventricle would be red."

b. In Caleb’s heart, what color would the blood be within the right and left ventricles, respectively? Caleb’s right ventricle contains a mixture of oxygenated and deoxygenated blood so it would be red and blue (purple). The left ventricle would still contain red blood.! Caleb’s heart allows oxygenated and deoxygenated blood to mix. Based on your knowledge of the heart and the great vessels, describe other anatomical abnormalities that cause the mixing of oxygenated and deoxygenated blood. Atrial Septal Defect would also cause the mixing of oxygenated and deoxygenated blood and differs from Caleb’s disorder only in that it’s a hole in the heart wall but higher up (between atria). Normally deoxygenated blood travels via the vena cavae into the right atrium, where it is delivered to the right ventricle and then pumped to the lungs for oxygen. In the left atria, blood is delivered from the lungs (oxygenated) via the pulmonary veins. With ASD, the oxygenated blood from the left atria leaks backward to the right atria where it is mixed with deoxygenated blood and then returned to the lungs. " "

Patent Ductus Arteriosus is a congenital heart defect that also causes the mixing of oxygenated and deoxygenated blood. Instead of the Ductus Arteriosus (a hole in the aorta) closing after birth, it remains open and continues to allow some blood to bypass the lungs. In a child with PDA blood in the Aorta can fall into the pulmonary arteries, mixing deoxygenated blood with oxygenated blood. The extra blood is sent to the lungs via the pulmonary arteries can cause severe congestion. ! What happens to Caleb’s systemic cardiac output as a result of his ventricular septal defect (VSD)? Explain your answer. Systemic CO will decrease. Caleb’s blood will flow to the left atria of the heart from the lungs, down to the left ventricle, and then flow back to the right side of the heart. This will decrease the stroke volume and in turn, decrease cardiac output from the left ventricle.! One of the problems that worried Tiffany was that Caleb seemed to be breathing too hard all the time. Let’s consider how this symptom is related to his heart defect. " a. Describe what would happen to the blood volume and pressure entering the pulmonary circuit as a result of his VSD. ! Due to his heart’s defect, there is extra blood volume in his pulmonary circuit and also extra pressure. His lungs and pulmonary veins would endure extra pressure and it would cause him to breathe heavily." b. Describe what would happen to the myocardium of Caleb’s right ventricle as a result of his VSD. The right ventricular myocardium will enlarge (Cardiomyopathy) and lose elasticity as a result of the constant pressure. Eventually, the right heart could fail.! Based on the location of Caleb’s defect, what part of the conduction system might be at risk for abnormalities? The inter-ventricular septum contains the left and right bundle branches and as a result of the VSD, could be more vulnerable because they aren’t being encased in the septum muscle. !

References

McKinley, Michael. (2016).#Anatomy & Physiology: An Integrative Approach. Second Edition. New York: McGraw-Hill Education.! (n.d.). Retrieved from http://www.heart.org/en/health-topics/congenital-heart-defects/aboutcongenital-heart-defects/patent-ductus-arteriosus-pda! (n.d.). Retrieved from https://www.khanacademy.org/science/health-and-medicine/circulatorysystem/circulatory-system-introduction/v/lub-dub! (n.d.). Retrieved from https://www.khanacademy.org/science/health-and-medicine/circulatorysystem-diseases/heart-valve-diseases/v/systolic-murmurs-diastolic-murmurs-and-extra-heartsounds-part-1! (n.d.). Retrieved from https://www.mayoclinic.org/diseases-conditions/ventricular-septaldefect/symptoms-causes/syc-20353495...