Question

Tiffany 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.” Tiffany 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, Tiffany 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.”

Short Answer--
Answer the following short answer questions, again with complete sentences.

1) With the defect in Caleb’s heart where it is, what would be different (irregular) with the blood flow through the heart? (ie explain blood flow during atrial and ventricular systole for this heart and why)

2) Explain what happens to Caleb’s systemic cardiac output as a result of his ventricular septal defect.

3) Why would this defect in the heart cause Caleb to breathe too hard? Explain in terms of the Blood volume in pulmonary circuit.

4) Based on the location of Caleb’s defect, what part of the conduction system might be at risk for abnormalities?

5) What would the basic results of a CBC blood test results be if this is Caleb's only problem? Low/ Normal/ High) and why

6) How about Hormone levels in the blood of the hormones gone over so far in lab?

Answer 1

Answers

1. Heart murmurs in children are often common and most of the murmurs do not require any additional treatment as they disappear after a certain period of time. The defect in Caleb’s heart should in the interventricular septum with a hole leading to abnormal blood flow between the left ventricle and right ventricle.

   The right and left ventricles are created by a wall during the fetal development and in some individuals, a defect in the wall allows the flow of blood from left ventricle to right ventricle leading to ventricular septal defect.

2. In Caleb, the blood flows from left to right ventricles due left-right blood shunt. As a result of this shunt, the volume of the left ventricle falls during systole before the opening of aortic valve resulting in decreased stroke volume and cardiac output from the left ventricle into the aorta.

3. Caleb is breathing harder because the amount of blood pumped into the pulmonary circuit is increased during each systole. This increased volume of blood needs more oxygen than normal and further, the pressure in this vessel also increases. Thus, this excess volume and pressure make Caleb breath harder.

4. The interventricular septum includes the bundle of His and the bundle branches. If the defect occupies a large part of the septum, then all these parts are at a risk for abnormalities.

5. In Caleb, the CBC tests would result in increased red blood cell count with an increase in hematocrit and hemoglobin levels than normal. The color of blood in the right ventricle would show both blue and red color as it has both deoxygenated and oxygenated blood.

6. The blood teste of Caleb would show increases B-type natriuretic peptide hormone. This hormone is released by the ventricular muscles in the heart in response increased pressure or volume on ventricle. In children with a severe heart condition, the BNP hormone level raises to 170 pg/ml indicating a greater risk.