352.The answer is c.(Moore and Dalley, pp 167–168.)The mitral valve is
best heard over the apex of the heart, which lies approximately in the fifth
intercostal space along the midclavicular line. The tricuspid valve is heard
most distinctly in the fifth intercostal space just to the right of the sternum
(answer b).The aortic (answer a)and pulmonary (answer d)valves are
best auscultated in the right and left second intercostal spaces, respectively,
adjacent to the sternum. Novalve is heard at the fourth intercostals space
on the right of the sternum (answer e).
353.The answer is c.(Moore and Dalley, pp 154–155.)The other condi-
tion that needs be further evaluated is aortic valve stenosis. In individuals
over 60, calcifications in the aortic valve can lead to a decrease in its func-
tion and restrict blood flow. Aortic valve stenosis often leads to enlargement
of the arch of the aorta due to blood turbulence as the blood rushes through
the valve and also hypertrophy of the left ventricle as a consequence of
increased workload to pump blood to the body. Left ventricle hypertrophy
will lead to the enlargement of the left heart border on the PA chest film.
There is noevidence for a pneumothorax (answer a)or pulmonary valve
stenosis(answer d).A ventricular septal defect (answer b)would produce
a systolic murmur and might lead to an increase in the right heart border,
notthe left. While mitral valve prolapse (answer e)would also tend to
increase the size of the left border of the heart, there should be nochange in
the size of the arch of the aorta.
354.The answer is d.(Moore and Dalley, p 175.)Coarctation of the aorta
often causes grooving of the undersurface of the ribs. Coarctation of the
aorta is a constriction of the aorta, often occurring near where the ductus
arteriosus had attached. The constriction of the aorta leads to a decrease in the
blood pressure within the lower limbs. Often there is a grooving of the infe-
rior surface of the ribs as blood flows into the internal thoracic (mammary)
arteries then inferiorly to the anterior portion of the intercostal arteries that
subsequently carry blood posteriorly to the thoracic aorta, distal to the
coarctation. The increased blood flow from anterior to posterior leads to
grooving on the inferior surface of the ribs, which can be seen on a PA chest
film. The constriction of the aorta may notbe evident on plain films.
Echocardiogram or CT of the chest should be used to confirm the diagno-
sis. Coarctation of the aorta is often seen in conjunction with other heart
Thorax Answers 485