Flying h4x0r
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Heres a topic we covered in the phsio chat today,
which side has greater cardiac output? the right or left side?
you'd think they'd be equal, but remember our physiologic shunt from pulm?
there is a little more blood that flows from the left ventricle, that goes straight through the pulm circuit and enters back to the left side, bypassing the right side.
i drew this picture to show you, its a lot less than 1L/min, but this should help you understnad what i mean
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| jessicaR
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thanx
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| mildus
Forum Guru
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nice info. thanks
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| twinkle
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R u saying the Physiologic Shunt that is
1) the blood in bronchial arteries which extensively anastomose with pulm. capillaries and thereby goes straight to the LA bypassing RA & RV
& 2)blood that flows straight from the coronary arteries to the left chambers of heart
is big enough to make a considerable difference in the CO between 2 ventricles?? coz I guess its quite too small an amount and also Kaplan (& most other books) says CO of both ventricle are equal.
Pls correct me if I`m missing something.
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| Zat
Forum Senior
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I agree with Twinkle.
CO of the RV must equal that of the LV, because both the systemic & pulmonary circulations are connected "in series". If one were to pump more than the other, failure of the pump(s) would occur.
So is the question/graph theoretical?
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| ggx12356
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The CO of RV and LV are not equal and this has been an issue with the AbioCor Total Artificial Heart.
Indirect Bronchial Shunt Flow Measurements in AbioCor Implantable Replacement Heart Recipients.
ASAIO Journal. 50(3):211-214, May/June 2004.
BHUNIA, S.K.; KUNG, R.T.V.
Abstract:
Bronchial shunt flows in the recipients of the electrohydraulic AbioCor implantable replacement heart have been measured indirectly. A built-in compliance chamber accommodates the differential flow output required of the two ventricles of the AbioCor. An occluder mechanism regulates the flow differential. For a thoracic unit, given a beat rate, an occluder setting, and the pressure differentials across the replacement heart ventricles, the atrial pressure difference depends only on the level of shunt flow present in the vasculature. For a replacement heart recipient, the bronchial shunt is the dominant shunt flow.
For patients implanted with the AbioCor, the beat rates and the occluder settings are known and the pressure differentials across the ventricles are estimated. Atrial pressures were measured using catheters. The bronchial shunt flow was deduced from in vitro characterization data based on these parameters. Available data from five patients in the ongoing clinical trial of AbioCor showed 0-1.4 L/minute bronchial shunt flows. Maximum variation for any individual patient was 1.1 L/minute.
(C)2004Amercian Society of Artificial Internal Organs
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| mildus
Forum Guru
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I would say that generally speaking they are equal, but if we want to be more precise, they are not equal (but the difference is not big)
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| mildus
Forum Guru
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maybe, the best answer would be "almost equal"
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| twinkle
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Thanks everyone for the input...otherwise... I`m sure many of us might `ve almost overlooked this equal/almost equal thing...and thanks mildus, "almost equal" sounds perfect.
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| Zat
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But for USMLE Step 1 standards........... what should one answer on the test?? This is the USMLE forum, and i do agree that many theoritical things tested do not completely agree with practical reality medicine.
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| Flying h4x0r
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i think its more important to keep in mind, that when someone is inhaling, CO in the RV is higher than in the LV.
Because of the decreased intrathoracic pressure, venous return increases, and CO of the LV decreases
thats hwat causes splititng of S2
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| the_holy_man
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There is actually a very nice flash animation of splitting of 2nd heart sound.
Check it out HERE
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| reet
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holy..man thanks fr good link
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