USMLE Forum Archives - USMLE Step 2 CK - IM 8
IM 8
TheOne - 11-02-06 19:16
A 30-year-old East Asian woman comes to the clinic complaining of chest pain. For the last 2
years, she has had intermittent nocturnal chest pain that lasts up to 10 minutes. The pain is
substernal and is described as a heavy pressure that radiates to her throat. The pain is a 6/10
on a pain scale and awakens her from sleep. It is associated with mild nausea and a clammy
sensation. In the past, she has tried antacids and a proton-pump inhibitor, neither of which
seem to help. Occasionally, significant aerobic exercise induces the pain. Aside from this
complaint, she reports being quite healthy; her only medical problem is Raynaud phenomenon,
severe during the winter months, and a history of migraine headaches treated with
sumatriptan. Social history is remarkable for the occasional use of cocaine. Vital signs and
physical examination are unremarkable; the patient appears young and healthy. An
electrocardiogram is unremarkable. A Holter monitor study is arranged. Given this patient's
likely diagnosis, which of the following is the most likely finding on Holter monitor during an
episode of chest pain?
A. Diffuse ST-segment elevation and PR segment depression
B. Normal electrocardiographic tracings
C. Prolonged QT interval with increased duration at night
D. Transient ST-segment depressions in the lateral leads
E. Transient ST-segment elevation in the inferior leads
TheOne - 11-02-06 19:16
A 30-year-old East Asian woman comes to the clinic complaining of chest pain. For the last 2
years, she has had intermittent nocturnal chest pain that lasts up to 10 minutes. The pain is
substernal and is described as a heavy pressure that radiates to her throat. The pain is a 6/10
on a pain scale and awakens her from sleep. It is associated with mild nausea and a clammy
sensation. In the past, she has tried antacids and a proton-pump inhibitor, neither of which
seem to help. Occasionally, significant aerobic exercise induces the pain. Aside from this
complaint, she reports being quite healthy; her only medical problem is Raynaud phenomenon,
severe during the winter months, and a history of migraine headaches treated with
sumatriptan. Social history is remarkable for the occasional use of cocaine. Vital signs and
physical examination are unremarkable; the patient appears young and healthy. An
electrocardiogram is unremarkable. A Holter monitor study is arranged. Given this patient's
likely diagnosis, which of the following is the most likely finding on Holter monitor during an
episode of chest pain?
A. Diffuse ST-segment elevation and PR segment depression
B. Normal electrocardiographic tracings
C. Prolonged QT interval with increased duration at night
D. Transient ST-segment depressions in the lateral leads
E. Transient ST-segment elevation in the inferior leads
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#1
Re: IM 8 kingkong - 11-03-06 21:13 i will go with (D).THIS IS A CASE OF MYOCARDIAL ISCHEMIA.not sure, kindly explain.
#2
Re: IM 8
TheOne - 11-06-06 12:24 Explanation: The correct answer is E. This patient has a classic presentation for variant angina, which is caused by coronary vasospasm that induces transient ischemia and
ST-segment elevations (choice E). This is seen most commonly in young women, usually occurs at night, though hyperventilation from exercise may induce symptoms (alkalosis leads to vasoconstriction), and can be worsened by agents such as cocaine or serotonergic agents like sumatriptan. Vasospasm can occur in any distribution, though it is seen most commonly in the right coronary artery, which, for most people, provides blood flow to the inferior portion of the heart.
Diffuse ST-segment elevation and PR segment depression (choice A) is suggestive of
pericarditis. One might expect pain relieved with leaning forward or a pericardial friction rub on physical examination. A recent viral illness and low-grade fevers are clues in the history that would point toward pericarditis.
Normal electrocardiographic findings (choice B) are unlikely if this woman has variant
angina. The association of other vascular phenomenon, such as Raynaud's phenomenon and migraine headaches, makes variant angina the most likely diagnosis. In such cases, the chest pain is associated with ST-segment elevations and occasionally depressed T-waves.
There is no reason to suspect a prolonged QT interval (choice C) as it may occur in certain metabolic disorders (hypo or heperkalemia) or in hypothermia.
Transient ST-segment depressions in the lateral leads (choice D) could be a sign for ischaemia but what we are looking here is a variant angina (ST-segment elevation).
#4
Re: IM 8 bingousmle - 07-19-10 09:04 looks like this patient has unstable angina as she has most of her symptoms of chest pain without any exertion.. so Transient ST-segment elevation in the inferior leads
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