QUESTION 109
A 64-year-old female is brought to the emergency room by her family. She developed a severe substernal chest discomfort 4 hours ago that was not relieved with antacids. In addition to the pain, she is nauseous and sweating. She says that the pain extends into her left and right arm. Her vital signs are BP of 161/92, heart rate of 102 bpm, and respiratory rate of 21 breaths per minute. Laboratory testing reveals a normal troponin I upon admission, and a repeat troponin I at 3 hours later is also normal. Of the following, what is the most likely diagnosis?
A. Stable angina
B. Unstable angina
C. Variant angina
D. non-ST elevation myocardial infarct
E. ST elevation myocardial infarct
Answer for Question 109
Answer: B (unstable angina)
Explanation: given the acute presentation and with no past history of similar symptoms, stable angina would not be the most likely diagnosis. While the symptoms have been on-going for 4 hours, the laboratory testing reveals no elevation of troponin I (and with the laboratory testing repeated 3 hours later) so there is no evidence of cardiac myocyte injury, as troponin I should have risen by this time, and thus, a non-ST or ST elevation myocardial infarct are not likely. Unstable angina is one form of acute coronary syndrome.
QUESTION 110
A 67-year-old female with a past medical history of hyperlipidemia, diabetes mellitus type II and a 40 pack-year smoking history is brought to the emergency room by her family. She developed a severe substernal chest discomfort 6 hours ago that was not relieved with antacids, and was described as being like someone standing on her chest. In addition to the pain, she is nauseous, sweating, and short of breath. She says that the pain extends to her jaw. Her vital signs are BP of 155/93, heart rate of 101 bpm, and respiratory rate of 20 breaths per minute. Laboratory testing reveals an elevated troponin I upon admission. Of the following, what is the most likely diagnosis?
A. Stable angina
B. Unstable angina
C. Acute myocardial infarct
D. Aortic dissection
E. Angiosarcoma of the heart
Answer for question 110
Answer: C (acute myocardial infarct)
Explanation: the symptoms are consistent with an acute coronary syndrome, with a pressure-like pain in the chest, which is associated with nausea, sweating, and shortness of breath, and with risk factors for coronary artery atherosclerosis, including her age, and history of hyperlipidemia, diabetes mellitus type II, and smoking history. The elevated troponin I indicates injury to cardiac myocytes, which rules out stable angina and unstable angina. The most likely diagnosis is an acute myocardial infarct (a form of acute coronary syndrome). While an aortic dissection can cause an elevated troponin I, given the lack of a past history of hypertension, and the nature of the chest pain, an acute myocardial infarct is more likely than an aortic dissection. An angiosarcoma of the heart would be very rare.
QUESTION 111
A 65-year-old female with a past medical history of hypertension and a 40 pack-year smoking history is brought to the emergency room by ambulance. She had developed a severe substernal chest discomfort 2 hours ago that was not relieved with antacids, and was described as being like someone standing on her chest. In addition to the pain, she is sweating and short of breath. She says that the pain extends to both her left and right arm. Her vital signs are BP of 162/90, heart rate of 103 bpm, and respiratory rate of 21 breaths per minute. Laboratory testing reveals an elevated troponin I upon admission. She sustains a cardiac arrest while in the emergency room. Of the following, what would an autopsy most likely identify in the myocardium?
A. Rupture of the free wall
B. Rupture of the interventricular septum
C. A large soft yellow discoloration
D. A large firm white discoloration
E. Grossly normal cardiac muscle
Answer for QuestioN 111
Answer: E (Grossly normal cardiac muscle)
Explanation: the symptoms are consistent with an acute coronary syndrome (i.e., pressure sensation in the chest associated with sweating and shortness of breath, and with the pain extending to the left and right arm). The elevated troponin I indicates damage to the cardiac myocytes, which would be consistent with an acute myocardial infarct. Her cause of death was a cardiac dysrhythmia. Ruptures occur around 1-3 days. A large soft yellow discoloration would be an acute infarct, with the yellow representing coagulative necrosis and neutrophilic infiltrate; however, to see a well-developed acute myocardial infarct, the time since the pain began would be around 1 day at least. A large firm white discoloration would be a remote myocardial infarct, and would indicate an age of 2 months or more.
QUESTION 112
A 63-year-old female with a past medical history of diabetes mellitus type II, hyperlipidemia, and a 30 pack-year smoking history is brought to the emergency room by ambulance. She developed a severe substernal chest discomfort 4 hours ago while playing cards with friends. She described the pain as being like someone was standing on her chest. In addition to the pain, she is short of breath and sweating. She says that the pain extends to her left arm. Her vital signs are BP of 149/90, heart rate of 102 bpm, and respiratory rate of 21 breaths per minute. Laboratory testing reveals an elevated troponin I upon admission. Of the following, which is most likely to be present in a coronary artery?
A. An atheroma, with a thin fibrous cap, that produces 75% stenosis
B. An atheroma, with a thick fibrous cap, that produces 75% stenosis
C. Marked focal neutrophilic infiltrate of the wall associated with fibrinoid necrosis
D. Focal granulomatous inflammation
E. Hemorrhage into an atheroma with rupture and resultant thrombosis of the lumen
Answer for Question 112
Answer: E (hemorrhage into an atheroma with rupture and resultant thrombosis of the lumen)
Explanation: the symptoms are consistent with an acute coronary syndrome (i.e., pressure sensation in the chest associated with sweating and shortness of breath, and with the pain extending to the left arm). The elevated troponin I indicates damage to the cardiac myocytes, which would be consistent with an acute myocardial infarct. An acute coronary syndrome is caused by an acute change within an atheromatous plaque, such as hemorrhage, thrombosis, or both. E. describes an acute change. A and B do not describe an acute change. Both A and B would be associated with stable angina. A. describes a vulnerable plaque, which would be predisposed to rupture, but, which, as described, is not consistent with an acute change. Both C and D, forms of vasculitis, could cause an acute myocardial infarct; however, compared to an acute plaque change occurring in the background of coronary artery atherosclerosis, vasculitis of the coronary arteries is a rare cause of an acute myocardial infarct.