Tiffaney is worried about her newborn son. Ever since she brought Caleb home from the hospital it has been so hard to get him to eat and he seems to be breathing too hard all the time. She stopped breast-feeding and tried every bottle and formula on the market, but nothing has worked. So, at his one month check-up, her stomach is in knots as they place Caleb on the scale. The nurse says, "9 pounds, 7 ounces." Tiffaney realizes Caleb has only gained one pound since he was born and she breaks into tears.
Dr. Baker checks over Caleb in the exam room, taking extra time feeling and listening to his chest. During the exam, Tiffaney explains her struggle with trying to get her son to eat and how he cries almost the entire day. After the exam Dr. Baker says, "When I listen to Caleb's heart I hear an extra sound called a murmur. I want to use an echocardiogram and an ECG to get a good picture of all the parts of his heart."
After a full day of tests, Tiffaney meets with Dr. Baker in his office. He explains, "After a careful review of all the information, I have discovered that Caleb has a hole in the heart muscle wall between his right and left ventricles. We call it a ventricular septal defect. That is probably why he has been so irritable and hard to feed. The hole is not very big, but he will still need to have surgery to repair it." Although the thought of her tiny son having surgery is terrifying, Tiffaney is relieved to know why things have been so tough at home.
Short Answer Questions
1. 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?
b. Where do you think would be the best place to auscultate Caleb's abnormal heart sound? Explain your answer.
2. Caleb has 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.
b. In relation to the normal heart sounds, when would you expect to hear the abnormal sound Dr. Baker heard? Explain your answer.
3. 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?
b. Based on your understanding of blood pressure and resistance in the heart and great vessels, explain your answer to question 3a.
4. 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?
b. In Caleb's heart, what color would the blood be within the right and left ventricles, respectively?
5. 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.
6. What happens to Caleb's systemic cardiac output as a result of his ventricular septal defect (VSD)? Explain your answer.
7. One of the problems that worried Tiffaney 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.
b. Describe what would happen to the myocardium of Caleb's right ventricle as a result of his VSD.
8. Based on the location of Caleb's defect, what part of the conduction system might be at risk for abnormalities?