Deck 4: The Heart, Coronary Vessels, and Pericardium

Question 1

A 61-year-old man was seen in the emergency department complaining of a feeling of pressure within his chest. On questioning, he said that he had several attacks before and that they had always occurred when he was climbing stairs or digging in the garden. He found that the discomfort disappeared with rest after about 5 minutes. The reason he came to the emergency department was that the chest discomfort had occurred with much less exertion

-The following comments concerning this case are correct except which?

A) The diagnosis is a classic case of angina pectoris.
B) The sudden change in history, that is, pain caused by less exertion, should cause the physician concern that the patient now has unstable angina or an actual myocardial infarction.
C) The afferent pain fibers from the heart ascend to the central nervous system through the cardiac branches of the sympathetic trunk to enter the spinal cord.
D) The afferent pain fibers enter the spinal cord via the posterior roots of the tenth to the twelfth thoracic nerves.
E) Pain is referred to dermatomes supplied by the upper four intercostal nerves and the intercostal brachial nerve.

Answer 1

The afferent pain fibers enter the spinal cord via the posterior roots of the tenth to the twelfth thoracic nerves.

Question 2

A 55-year-old woman has severe aortic incompetence, with the blood returning to the cavity of the left ventricle during ventricular diastole.

-To hear the aortic valve with the least interference from the other heart sounds, the best place to place your stethoscope on the chest wall is

A) the right half of the lower end of the body of the sternum.
B) the medial end of the second right intercostal space.
C) the medial end of the second left intercostal space.
D) the apex of the heart.
E) the fifth left intercostal space $3.5 \mathrm{in}$ . $(9 \mathrm{~cm})$ from the midline.

Answer 2

the medial end of the second right intercostal space.

Question 3

A 33-year-old woman was jogging across the park at 11 PM when she was attacked by a gang of youths. After she was brutally mugged and raped, one of the youths decided to stab her in the heart to keep her silent. Later in the emergency department she was unconscious and in extremely poor shape. A small wound about $0.5 \mathrm{in}$ . in diameter was present in the left fifth intercostal space about 0.5 in. from the lateral sternal margin. Her carotid pulse was rapid and weak, and her neck veins were distended. No evidence of a left-sided pneumothorax existed. A diagnosis of cardiac tamponade was made.

-The following observations are in agreement with the diagnosis except which?

A) The tip of the knife had pierced the pericardium.
B) The knife had pierced the anterior wall of the left ventricle.
C) The blood in the pericardial cavity was under right ventricular pressure.
D) The blood in the pericardial cavity pressed on the thin-walled atria and large veins as they traversed the pericardium to enter the heart.
E) The backed-up venous blood caused congestion of the veins seen in the neck.
F) The poor venous return severely compromised the cardiac output.
G) A left-sided pneumothorax did not occur because the knife passed through the cardiac notch.

Answer 3

The knife had pierced the anterior wall of the left ventricle.

Question 4

A 38-year-old woman was taken from the scene of an automobile accident to the local hospital. She had been driving her car without a seat belt on and had hit a utility pole head on. On examination she was conscious and alert but had sustained severe facial and chest injuries. A careful examination of the chest cage revealed the presence of a sternal fracture (middle of the body) and fractures of the third and fourth left ribs near their costochondral junctions. After an extensive workup it was decided that the patient had a ruptured pericardium.

-The following observations are in agreement with the diagnosis except which?

A) Blunt trauma had been applied to the anterior chest wall.
B) The fractures of the third and fourth left ribs were situated over the anterior surface of the heart.
C) The left dome of the diaphragm was paralyzed.
D) The patient had tachycardia.
E) The right lateral margin of the pericardium was the site of the rupture.
F) There were diminished breath sounds over the lower lobe of the left lung.

Question 5

A 21 -year-old man was walking along a city street when suddenly a burst of automatic gunfire came from a passing car. The man, who was an innocent bystander, was struck in the front of the chest by a stray bullet. He was rushed to the emergency department by an ambulance. The position of the entry wound was the fourth left intercostal space about 3 in. from the midline.

-The following observations are in agreement with the findings in this patient except which?

A) The right ventricle is the most likely chamber of the heart to be injured should a bullet enter the frontal surface of the chest.
B) If the bullet continues on its path, the left ventricle is also damaged, since the left ventricle lies posterior to the right ventricle.
C) The circumflex branch of the left coronary artery may be damaged by the bullet as it runs down the anterior surface of the heart.
D) The chordae tendineae of the anterior cusp of the tricuspid valve could be injured.

Question 6

A 5-year-old boy was seen in the emergency room following an attack of breathlessness during which he had lost consciousness. The mother, on questioning, said that her child had had several such attacks before and sometimes his skin had become bluish. Recently she had noticed that he breathed more easily when he was playing in a squatting position; he also seemed to sleep more easily with his knees drawn up. On physical examination, the child was found to be thinner and shorter than normal. His lips were cyanotic, and his fingers and toes were clubbed. A systolic murmur was present along the left border of the sternum, and the heart was considerably enlarged to the right. An extensive workup, including angiography, demonstrated tetralogy of Fallot.

-Using your knowledge of cardiac development, critically read the following observations made in this case and determine the one that is incorrect.

A) The systolic murmur heard along the left border of the sternum was caused by the pulmonary stenosis.
B) A right-to-left shunt of blood occurs through the large ventricular septal defect.
C) The aortic blood is poorly oxygenated resulting in the impaired growth of the child, the cyanosis of the lips, and the clubbing of the fingers and toes
D) Maintaining the squatting position during play and sleeping with the knees drawn up increases the peripheral resistance in the systemic circulation and decreases the right-to-left shunt through the ventricular septum.
E) If the patient had a large ductus arteriosus as well as the tetralogy of Fallot, the cyanosis would be much worse.

Question 7

A 43-year-old woman was seen in the emergency department complaining of a severe localized pain over the left side of the chest. She stated that the pain started quite suddenly, about 1 hour previously, when she was reaching for a book on a high shelf. On further questioning she disclosed that she had been sailing with her husband the previous day and that they had been caught in a storm. She described the pain as a continuous dull ache that was made worse by taking deep breaths and using the left arm. She indicated that the pain was localized over the sixth left costal cartilage about 2 in. to the left of the sternum, which corresponded to an area of tenderness over the sixth left costochondral junction.

-The following possible conditions could explain the severe chest pain. Choose the most likely diagnosis based on your knowledge of anatomy.

A) Myocardial infarction
B) Lobar pneumonia of the left lung
C) Tearing of muscle fibers in the chest wall, possibly the serratus anterior muscle
D) Separation of the sixth left costochondral joint or an acute costochondritis
E) Left-sided pleurisy

Question 8

The following anatomic structures are penetrated by a needle when performing a pericardiocentesis except which?

A) Skin and subcutaneous tissue
B) The aponeuroses of the external and internal oblique muscles
C) The left parietal and visceral layers of pleura
D) The rectus abdominis muscle
E) The diaphragm and fibrous pericardium