Case study 1: Crimes of the heart
Short Answer Questions:
Dr. Baker spends a long time listening to (auscultating) Caleb’s heart.
Where on the thoracic surface do you auscultate to the tricuspid, mitral (bicuspid), pulmonary, and aortic valves?
The tricuspid valve is located in the Fourth left ICS, left sternal border.
The bicuspid valve is located in the Fifth ICS, left mid-clavicular line.
The pulmonary valve is located in the Second left intercostal space (ICS), left sternal border
The aortic valve is located in the Second right intercostal space (ICS), right sternal border
Where do you think would be the best place to auscultate Caleb’s abnormal heart sound? Explain your answer.
The tricuspid valve is the best place to auscultate for Caleb’s abnormal heart sound. the the lower left sternal border, with radiation to the right lower sternal border is the area which overlies the defect.
Caleb has abnormal heart sounds that tipped the doctor off to a problem.
Name the normal sounds of the heart and indicate what causes these sounds.
The normal sounds of the heart is called “lub-dub”. The “lub” portion is the closure of the AV valve and the “dub” portion is the closure of the SL Valve.
In relation to the normal heart sounds, when would you expect to hear the abnormal sound Dr. Baker heard? Explain your answer.
You would hear the abormal heart sound as the blood passes between the left and right ventricle. The murmurs would indicate a valve problem.
The defect in Caleb’s heart allows blood to mix between the two ventricular chambers.
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 move from left-to-right ventricle
Based on your understanding of blood pressure and resistance in the heart and great vessels, explain your answer to question 3a.
The blood would normally move from right to left ventricle and the left side of the heart would have to overcome an greater resistance. Since there’s an opening in the septum more blood is shunted from the left to right because the left ventricle is stronger.
In a healthy baby, what color would the blood be within the right and left ventricles, respectively?
Right ventricle would be blue (oxygen poor)
Left Ventricle would be Red (oxygen Rich)
In Caleb’s heart, what color would the blood be within the right and left ventricles, respectively?
Left ventricle would be red (oxygen rich)
Right Ventricle would be Mixed blood (red and blue)
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.
patent ductus arteriosus, where a temporary channel that connects the pulmonary artery and the first segment of the descending thoracic aorta during fetal growth fails to close after birth, causing some mixing of oxygenated and deoxygenated blood.
What happens to Caleb’s systemic cardiac output as a result of his ventricular septal defect (VSD)? Explain your answer.
His cardiac output would be reduced as an result to VSD. The backflow of the blood from the left ventricle to right would be the cause because the resistance in the blood wouldn’t be as strong anymore.
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.
Describe what would happen to the blood volume and pressure entering the pulmonary circuit as a result of his VSD.
As an result of his VSD the blood volume would be high because the ventricles are working harder than they normally would. The pressure would also be higher since the extra blood is passing through the aorta into the lungs.Describe what would happen to the myocardium of Caleb’s right ventricle as a result of his VSD.
Based on the location of Caleb’s defect, what part of the conduction system might be at risk for abnormalities?
The bundle branches that travel down the interventricular septum would be at risk of abnormalities.