NBME F2 S 1

Prep for USMLE Forum

» Log in | Register

Forum

Step 1

Match

Prep4USMLE Forum » USMLE Step 1 Forum » Pathology Forum

NBME F2 S 1

Author

10 Posts

nadiabarati

06/24/06 - 07:27 PM

A 72-year-old woman comes to the physician because of an episode of acute substernal chest pain that occurred while she was rushing to catch a bus. She has basilar crackles at both lung bases. S1 is normal and S2 is decreased. A grade 3/6 systolic murmur is heard best at the upper right sternal border and radiates to the neck. The following data obtained during cardiac catheterization were taken before and during exercise:
Left ventricular volume Aortic P End diastolic End systolic Heart rate
(mm Hg) (mL) (mL) (/min)

Control 130/70 140 50 85
Exercise 160/80 165 58 120

While exercising, the patient has shortness of breath but no chest pain. Which of the following is the most likely cause of the shortness of breath?
A) Decreased cardiac output during exercise
B) Decreased pulmonary blood flow
C) Increased aortic pressure
D) Increased end-diastolic pressure of the left ventricle during exercise
E) Tachycardia

sridevibandaru24
Forum Guru

Topics: 33
Posts: 434

06/25/06 - 01:41 PM

nadiabarati

06/25/06 - 01:47 PM

I think it's Aortic stenosis

So A

robin082006
Forum Hero
avatar

Topics: 471
Posts: 5,123

06/25/06 - 02:28 PM

This is Aortic stenosis

A or E?

I think E is better choice. CO may be constant due to increased heart rate (CO=SV*HR)

___________________
The Key to Succeed is Patience.

nadiabarati

06/25/06 - 02:52 PM

tachycardia is not a CAUSE of shortness of breath.

seconds
Forum Newbie

Topics: 3
Posts: 27

06/27/06 - 12:09 PM

CHF (lung crackles) in the setting of Aortic stenosis is due to a combination of systolic dysfunction (a decrease in the ejection fraction) and diastolic dysfunction (elevated filling pressure of the LV, ...so i think A

robin082006
Forum Hero
avatar

Topics: 471
Posts: 5,123

06/27/06 - 12:14 PM

yeah, I forgot the question asks about shrotness of breath, thanks.

___________________
The Key to Succeed is Patience.

Diego Casali
Forum Elite
avatar

Topics: 7
Posts: 234

06/28/06 - 07:44 AM

sosikan
Forum Junior
avatar

Topics: 3
Posts: 78

08/14/06 - 09:01 AM

if the problem is aort stenosiz why s2 get decreased...it must increased...?

docarchana
Forum Guru

Topics: 70
Posts: 515

08/16/06 - 07:00 PM

#10

CO = SV * HR. during exercise, both SV (EDV-ESV) & HR are increased. then how can we say A is the answer?

You don't have permission to post.