Cardiovascular old exam questions

[Kristen Chen]

Hello all! 

I hope everyone is well and enjoying the cardiovascular system! 

On the off chance that you find yourselves with idle time or would just like to jump-start on preparing for exam 3, I have attached four questions from old exams that I think will aid your reviewing process and understanding.  I will post the answers to these questions in a separate document by Sunday night.  

Hope this helps!

~Kristen 

[Kristen Chen]

Hi Guys! 

I'm attaching the answers to the cardiovascular problems I posted up earlier last week. 

Hope these help!

~Kristen 

[Kristen Chen]

Per request, some more questions! 

CARDIOVASCULAR

1.       (2009) Background information: Occasionally a purkinje fiber may become overly excitable and depolarize more rapidly than the SA node. This premature action potential spreads to the ventricles before the SA node can initiate a normal AP. The result is a PVC, or a premature ventricular contraction.  The interval between a PVC and the next normal beat is longer than the average interval between heart beats. The Question: The stroke volume of the next heartbeat after a PVC is usually larger than normal. Please explain why.  

2.       (2009) A student reported to the health center complaining of weakness and an abnormal heart rate. In a physical exam, her heart rate was rapid and very irregular. No P waves could be detected on her electrocardiogram.  The QRS complexes were normal in shape but the interval between them was irregular.  State the most likely diagnosis of her condition. Would cardiac output be seriously impaired by her condition? Briefly explain why or why not.

3.       (2008) If the stroke volume of the left ventricle is 65 ml and the stroke volume of the right ventricle is 66 ml, what will happen to the relative distribution of blood in the systemic and pulmonary circulations over time? Briefly explain any problems this may cause.

4.       (2007) Define heart failure. Briefly explain why pulmonary edema is a common result of left heart failure.

[Kristen Chen]

Hi Guys!

Here are the answers to the newer set of cardiovascular questions I recently posted for you all.  Hopefully you have already had a chance to work them out on your own. These are the answers directly from Herrera's exam so hopefully it gives you all an idea of how much detail he is expecting.  Good luck everyone! You guys are gonna do great! 

(2009) Because the interval between a PVC and the next normal beat is longer than usual, the heart fills for a longer period of time, resulting in a greater end-diastolic volume.  According to the Starling curve, the subsequent stroke volume will be correspondingly larger. 

(2009) The most likely diagnosis is atrial fibrillation.  Cardiac output would not be seriously impaired by her condition.  Even though the atria are not contracting normally, ventricular filling would not be greatly affected because most ventricular filling occurs during diastole, before the atria contract.  The ventricular filling is driven in the vena cava and pulmonary veins. 

(2008) With each heartbeat, output from the left side will fall behind output from the right side by 1 mL, with the result that blood will accumulate in the pulmonary circuit.  The resulting congestion of blood in the lung would lead to increase leakage of fluid from lung capillaries, leading to pulmonary congestion. This type of left ventricular inadequacy is called congestive heart failure. 

(2007) Heart failure refers to a condition in which the heart cannot maintain adequate cardiac output, due to some insufficiency or obstruction of its pumping.  In left heart failure, inadequate cardiac output causes an increase in pressure in pulmonary veins.  This leads to increased pressure in pulmonary capillaries which increases the filtration of fluid across capillary walls, causing edema.