new_n_lost
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A 57-year-old female is found unconscious on her kitchen floor after having suffered a myocardial infarction. She has pulmonary edema and distended jugular and peripheral veins. A midsystolic
gallop is heard upon chest auscultation.
EKG shows prominent Q waves in leads II, III, and aVF.
Which of the following is most consistent with the patient's condition?
Preload Cardiac output PAWP CVP Vascular resistance Mixed venous oxygen
A. Increased Decreased Decreased Increased Increased Decreased
B. Increased Increased Decreased Decreased Decreased Increased
C. Increased Decreased Increased Increased Increased Decreased
D. Increased Increased Increased Increased Decreased Decreased
E. Decreased Decreased Increased Decreased Increased Decreased
F. Decreased Increased Decreased Increased Decreased Increased
G. Decreased Decreased Increased Decreased Decreased Decreased
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| doc179
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is it C ?
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| Luckyall
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C ? CO low and reflex arteriolar vasoconstriction ?
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| monam84
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(C.) Here's my explanation: I think she had an MI, and the gallop may be mitral prolapse (just a thought). Her preload would be increased because her arterioles and veins would constrict pushing more blood into her heart, but her CO is low because of heart failure, also the mitral prolapse is pushing blood into her LA during systole so the PAWP would be higher. Also, vascular resistance is of course higher becase of receptors in the carotid sinus detecting the low pressure. My question is what would mixed venous oxygen be? How would it be affected?
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| new_n_lost
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The correct answer is C.
This case depicts the classic picture of cardiogenic shock. This typically occurs after ischemic myocardial injury, acute valve dysfunction associated with endocarditis, blunt chest trauma, acute myocarditis, or end-stage cardiomyopathy.
Left ventricular function is compromised, therefore cardiac output is diminished. Preload is increased because blood from the right side of the heart and pulmonary circulation is pumped into an already filled left ventricle (this explains the S3 and S4 sounds that presented as a midsystolic gallop).
Pulmonary artery wedge pressure, measured with a Swan-Ganz catheter, reveals left atrial pressure as well as left ventricular end-diastolic pressure and is elevated in heart failure.
Left ventricular failure causes increased left atrial pressure, which results in increased hydrostatic pressure in pulmonary vasculature.
Once hydrostatic pressure is higher than oncotic pressure, fluid from the circulation leaks into the alveolar spaces, causing pulmonary edema and dyspnea.
Eventually, the right ventricle can no longer pump blood against the increased pulmonary pressure and fails. This causes a backup of blood, which results in increased central venous pressure.
Systemic vascular resistance is increased in an attempt to compensate for the diminished cardiac output. Mixed venous oxygen levels are reduced because of increased tissue demand for oxygen
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| lq2006
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C
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| dr_student
Forum Newbie
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hi nnl,
u explained very well.this is a inferior MI
But s3 s4 wont be in systole but diastole
s3--due to rapid ventricular filling in early diastole.
s4-- due to atrial contraction
And the decrease in syst venous o2 is due to decrease in bld flow leading to increased o2 extraction..not becoz of increased demand of tissues.Might be becoz of decreased diffusion of o2 due to pulm edema--decreased syst o2 --decreased venous o2
correct if i m wrong.
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| dncosta
Licensed, finally
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C
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