








USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam 

Thread Tools  Search this Thread  Display Modes 
#1




Calculate Myocardial Oxygen Consumption!
A 65yearold man is hospitalized with severe chest pain. Various studies are done, including measurements of coronary blood flow and coronary sinus O2 content.
The values obtained are: Coronary blood flow 50 mL/min per 100 g of heart Arterial O2 content 19 mL O2/dL blood Coronary venous O2 content 2 mL O2/dL blood What is the myocardial O2 consumption per 100 g of cardiac muscle is (in mL O2/min) (A) .12 (B) 8.5 (C) 9.5 (D) 200 (E) not calculable from these data 
The above post was thanked by:  
hiratamkeen (10242011) 
#2




E) ...
At least that's what my calculatings skills and lazyness tell me =))
__________________
Ambition is a dream with a V8 engine. EP 
#3




Bbbbbbbbbbbbbbb

#4




Can you explain your answer please?

#5




What is the source of this question?

#6




i think the ans is B
because if we use the formula of the ficks principle where flow=O2 consumption/AV we have the flow.and we have arterial(A) and venous(v) oxygen concentration so we can calculate the Oxygen(O2) uptake. Atleast thats what i can think how we need to calculate 
The above post was thanked by:  
drhnis (10252011) 
#7




B  is just calculation

#8




The answer is b

#9




i still dont understand how did u calculate the answer

#10




Quote:
The calculation formula is MVO2=(CaO2 CvO2)XCBF but first you should convert 19 and 2 per DL to Grams they will be 19/100=0.19 and 2/100=0.02 so then you will calculate easily , as1dl is 100 gram (0.19 0.02)x50=8.5 
The above post was thanked by:  
docnok (10252011), DocSikorski (10242011), Dr.Lacune (08212012), dr.muhamad (10252011), Learner (10252011) 
Tags 
Cardiovascular, Physiology, Step1Questions 
Thread Tools  Search this Thread 
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Breathing 100% Oxygen, why not hypoventilate?  chienpolska  USMLE Step 1 Forum  4  01072013 09:25 AM 
Anterior myocardial infarction  aktorque  USMLE Step 1 Forum  15  03282012 11:51 AM 
how to calculate GFR  laurier  USMLE Step 1 Forum  1  10242011 08:30 PM 
Less than 6 hours after myocardial infarction  Seetal  USMLE Step 1 Forum  9  09162011 09:02 AM 
oxygen saturation  qurat21  USMLE Step 1 Forum  8  08142011 02:17 AM 
