Heart sounds, BP and pulse

[rhan101277]

I just wanted to see if I had this all right in my head. When you are listening to heart sounds with your stethoscope, you are simply hearing the heart valves opening and closing. When you check the pulse, you are feeling the left ventricle contractions, since the right ventricle is pumping blood to the lungs I don't see how it could be felt.

My question is how do you know the right ventricle is working properly (besides EKG). Is that where the oxygen saturation check comes in. If the right ventricle stops working you will still feel a pulse, but the pt will deteriorate fast due to low oxygen in the blood. Obviously I think you would notice a blood pressure change when this occurs (low bp), due to the chemoreceptors in the aorta detecting low oxygen, which then may lead to constriction of the blood vessels, with the body trying to bring bp back up.

Maybe I have this wrong, but I feel like its right.

When you go on a call, going in depth like this doesn't happen right. You are just worried about ABC's and getting the critical injuries taken care of. But knowing how everything works is a plus right?

 

[Ridryder911]

I am really glad to see your interest in physiology and applaud it. With this I encourage you to definitely make some notes to ask your instructor for better clarification.

Yes, one is hearing the valves opening and closing, in the lub dub. It is far more complicated than that to be able to explain the differential in the sounds of the lub dub itself. Heart tones itself is on-going learning program that I find one of the most difficult assessments. For example crescendo with a spit S1, hollow systolic murmur, and so on... I have taken courses lasting several weeks to begin to understand the complexity of heart tones, and still consider myself a novice at this.

When one is feeling a pulse. one is only feeling the wave or the "pulsation" of the blood flow by compressing an artery against a bone or solid organ. One does not feel pulmonary circulation (right side heart blood flow to the lungs per pulmonary artery (the only artery that carries unoxygenated blood)) as it is going through the pulmonary tree and being oxygenated. Blood is ejected through the left atrium into the left side (left ventricle), now what produces the "pulse" is the force of ejecting the blood from the left ventricle. This is what called "ejection fraction" a fancy name of how much blood is "ejected" out from the left ventricle in one cycle. Remember, the blood flow to the body from the heart (is called systemic circulation) and is produced by the pressure from the left ventricle contracting (Systole). Now the heart muscle requires its own circulation or to feeds itself. This occurs in the resting phase (diastole) by blood flowing into small opening areas at the top of the aorta (largest artery) that feeds the small arteries of the heart (coronary circulation). Yes, it is an amazing little pump isn't it?

Now, one can surely see why it is important to know not just that one is having an heart attack (AMI) but where it is located at... If one knows the area one can expect what damage to occurs, what to expect in outcomes, difference in treatment and what to prepare for (survive or death). For example a right side will cause a poor level in the preload thus causing the heart not to being able to receive blood (preload) as well and if one was to give Nitroglycerin (NTG) it could cause more damage by dilating the vessels, allowing pooling to occur. The opposite for the opposite side of the heart. Left ventricle heart attacks will have what? .. Yep, poor pulses because .. again, the major portion of the "pump" has been damaged. ..

Now, one recognize our concerns of blindly administering NTG, without an XII lead EKG prior. One cannot differentiate where the heart attack is without it. Again, truthfully NTG is not really for heart attacks but rather for Angina which is constriction of those coronary arteries that feed the heart. It is commonly used to allow dilation to occur to allow more blood supply to the injured site.. again, the thought maybe it will help.

Now, many get confused not realizing that the heart is really a four chamber pump. Each chamber is responsible for something. The old blood (unoxygenated) coming in from body is transported per the largest vein (superior & inferior Vena Cava), which is literally flowed into the right atrium. Yes, there is some atrial contractions that assist the blood flow into the right ventricle; but realistically it is very little and technically one could do without a majority of the right atrium. The blood flowing into the right atrium to the right ventricle is called "preload" and when it enters the lungs it is called pulmonary circulation. Where it is oxygenated and the cycle repeats itself.


Hopefully, this will help.. I watered it down quite a bit purposefully. One can study circulatory and oxygenation problems for decades and realize that one only knows a small amount in perspective and complexity of the system. Alike our friend Vent who has spent decades learning and studying the complexity of it....

Footnote: Be sure to fully understand common circulation before attempting to learn another human circulation: the fetal circulation.. that itself is a whole different and complex system..


Good luck,
R/r 911

 

[NC-EMT08]

What a great, detailed response. So if the left ventricle is not contracting properly, would it cause pulmonary edema due to a backup of blood into the lungs? Also, would this (the failure of the left vent. to pump adequately) essentially be the same as cardiogenic shock?

 

[JPINFV]

My question is how do you know the right ventricle is working properly (besides EKG). Is that where the oxygen saturation check comes in. If the right ventricle stops working you will still feel a pulse, but the pt will deteriorate fast due to low oxygen in the blood. Obviously I think you would notice a blood pressure change when this occurs (low bp), due to the chemoreceptors in the aorta detecting low oxygen, which then may lead to constriction of the blood vessels, with the body trying to bring bp back up.

One thing that's not quite as intuitive as one would thing after realizing it is that the heart is like 2 pumps in line. The right side and the left side have to pump at the same rate or else blood will begin to back up (i.e. edema). So, if one side starts to fail, then the total amount of blood pumped will decrease regardless of which side is failing. The big difference is where the blood will back up to (right side=systematic edema, left side=pulmonary edema). Either will lead to the body start to compensate by constricting blood vessels and releasing hormones in an attempt to increase the blood pressure by itself.

When you go on a call, going in depth like this doesn't happen right. You are just worried about ABC's and getting the critical injuries taken care of. But knowing how everything works is a plus right?

The thing with better background information, especially for EMT-Basics (I don't know what level you're at, but it's not relevant for this comment) is that it helps with those borderline calls. If the patient is obviously critical, then basic level treatment is fairly obvious. If the patient is obviously minor, then again the treatment is fairly obvious. The problem that education helps greatly with is for those patients that fall on the line of "call medics/emergently transport." Regardless of how conservative or cavalier a provider is, that line is still going to be someplace. In addition, it does help putting things together on scene in your head, but it isn't something that you're going to stop and think hard about.

Footnote: Be sure to fully understand common circulation before attempting to learn another human circulation: the fetal circulation.. that itself is a whole different and complex system..

Foramen ovale and patent ductus arteriosus for the win (among a few other special structures).

 

[rhan101277]

I just thought about how if the right ventricle wasn't working, then you should heart that in the heart sounds, because I believe if the ventricle does not contract you won't get the change in blood pressure needed for the atrium to contract and release its blood into the ventrical. Also the semilunar pulmonary valve would also not be working.

Another thing that I wondered while reading the book. This has to do with blood transfusions. Knowing that a baby can have a different blood type than the mother, how can they share blood via the umbilical cord? Since different blood types can cause clotting (e.g. giving A type blood to a B type person).

Also I just don't want to do the minimum to be a basic, who is to say the medic won't ask for my advice or something. Also next fall I will go to paramedic class, so I should have a year of part-time work under my belt.

 

[JPINFV]

I just thought about how if the right ventricle wasn't working, then you should heart that in the heart sounds, because I believe if the ventricle does not contract you won't get the change in blood pressure needed for the atrium to contract and release its blood into the ventrical. Also the semilunar pulmonary valve would also not be working.

The ventrical contracting has nothing to do with atrial contracting. Heart conduction is essentially a one way street (there are some bypasses, though) and the atrium coming before the ventricals.

Another thing that I wondered while reading the book. This has to do with blood transfusions. Knowing that a baby can have a different blood type than the mother, how can they share blood via the umbilical cord? Since different blood types can cause clotting (e.g. giving A type blood to a B type person).
They don't actually share blood. Both maternal blood and fetal blood is present in the placenta. In the placenta, nutrients, wastes, and gasses are transfered between maternal blood and fetal blood via a variety of mechanism (some active, some passive) and then the fetal blood is moved back to the fetus through the umbilical cord.

Also I just don't want to do the minimum to be a basic, who is to say the medic won't ask for my advice or something.

The rest of this post contains the minimum answers for a basic to know. (note: knowing the minimum is not knowing the ideal level of information. Not even close).

 

[Ridryder911]

My post was just to clarify and wet your taste buds to learn more. In reality it is alike an auto mechanic.. you can have one that hooks it up to a computer and it tells them where and what to fix or you can have one that actually knows the parts and how they work together to make combustion. A good mechanic can listen, look, smell and they feel how the engine is working with vibrations, timing. They then develop a problem list then they will place it onto a computer and then look further into it; if needed.

Which would you rather have working on your car? Now, compare that with some medics...

You can't identify what is broken if you don't know the parts and how they work...

R/r 911

 

[rhan101277]

The Anatomy/Physiology book has a wealth of information. Now I see why there are so many doctors are specialized. Its a lot to know and would definitely take more than just taking college level courses to get it down. I guess you just get good enough at what you need to know to do your job. The most important things that have to do with airway, breathing and circulation and knowing how those systems work and how they are effected when certain things go wrong.

 

[rhan101277]

The ventrical contracting has nothing to do with atrial contracting. Heart conduction is essentially a one way street (there are some bypasses, though) and the atrium coming before the ventricals.

Another thing that I wondered while reading the book. This has to do with blood transfusions. Knowing that a baby can have a different blood type than the mother, how can they share blood via the umbilical cord? Since different blood types can cause clotting (e.g. giving A type blood to a B type person).
They don't actually share blood. Both maternal blood and fetal blood is present in the placenta. In the placenta, nutrients, wastes, and gasses are transfered between maternal blood and fetal blood via a variety of mechanism (some active, some passive) and then the fetal blood is moved back to the fetus through the umbilical cord.

The rest of this post contains the minimum answers for a basic to know. (note: knowing the minimum is not knowing the ideal level of information. Not even close).

What do you mean by the rest of the post contains minimum answers? This was the end of your post. Also if the maternal and fetal blood are present in the placenta whats stops a reaction from occurring if the maternal blood is A Type and the fetal blood is B-Type. Are the antibodies not present in the placenta?

 

[BrianJ]

I just wanted to see if I had this all right in my head. When you are listening to heart sounds with your stethoscope, you are simply hearing the heart valves opening and closing.

As I understand it the lub and dub sounds are actually the turbulence from the blood moving through the valves. I know it's getting a bit technical but "when listening to heart sounds what are you hearing?" seems like it will pop up on an exam somewher. So "lub" represents blood flowing through the bicuspid and tricuspid valves, while "dub" is blood leaving the atrium going through the semilunar valves.
A cool site that kinda helps put everything together;
http://library.med.utah.edu/kw/pharm/hyper_heart1.html

Brian

 

[JPINFV]

What do you mean by the rest of the post contains minimum answers? This was the end of your post.

The information contained in this thread, while vital, is unfortunately well past what is expected from EMT-Basics.

Also if the maternal and fetal blood are present in the placenta whats stops a reaction from occurring if the maternal blood is A Type and the fetal blood is B-Type. Are the antibodies not present in the placenta?

Both maternal and fetal blood are present in the same organ, but blood doesn't mix. I honestly don't know what's stopping immune cells from crossing over and causing a reaction in the baby.

 

[Ridryder911]

I just wanted to see if I had this all right in my head. When you are listening to heart sounds with your stethoscope, you are simply hearing the heart valves opening and closing.

As I understand it the lub and dub sounds are actually the turbulence from the blood moving through the valves. I know it's getting a bit technical but "when listening to heart sounds what are you hearing?" seems like it will pop up on an exam somewher. So "lub" represents blood flowing through the bicuspid and tricuspid valves, while "dub" is blood leaving the atrium going through the semilunar valves.
A cool site that kinda helps put everything together;
http://library.med.utah.edu/kw/pharm/hyper_heart1.html

Brian

Yes & no. actually it is not so much the turbulence as it is the opening and closing of the valves. That is why there is clicks and murmurs, etc..

S1 & S2 are the natural heart sounds you will hear as the tricuspid and pulmonic versus the mitral and aortic valves. As one really gets into heart tones, you will also learn grades of murmurs, closing, partial closing, late opening/closure, mid-diastolic, and on and on.. alike I said a very great assessment tool but very few (including physicians) really get into.


Actually A & P is one thing that every physician is expected to have a thorough knowledge on. Even specialist such as orthopedics, should be familiar with details of embryonic development as much as the O.B./Gyn should know bone markings. Most physician may forgive another speciality of not knowing the "current treatment modality" of their speciality but I have seen very few that forgive a physician of not knowing the basics... i.e anatomy, pathophysiology, chemistry... in which all should have mastered before entering medical school.

I know that I tend to feel the same way in regards to nurses & medics, not realizing most do not expand from the basics. In my own personal goal; I have over two years (I, II, advanced patho, gross anatomy) worth of studies on anatomy & physiology alone & still feel at lost sometimes.

Alike medical terminology, if one masters it, they will master medicine and make their job easier. Study hard.. it will pay off.

R/r 911

 

[Ridryder911]

The information contained in this thread, while vital, is unfortunately well past what is expected from EMT-Basics.

Both maternal and fetal blood are present in the same organ, but blood doesn't mix. I honestly don't know what's stopping immune cells from crossing over and causing a reaction in the baby.

I could tell you, but then you would never remember... (hint: why mothers recieve RhoGam injection)..

R/r 911

 

[rhan101277]

Yes but the RG injection is just if the baby has negative or positive blood type. The injection is used after the first baby, to prevent complications from the same babies antibodies. The mother is injected with it to prevent reactions.

Knowing this RG injection is used to give the mother build up of specific antibodies as not to cause harm when another baby is born with a different, either positive(mom) negative(baby). I think it can cause issues in the mother.

So knowing this the blood has to somehow, somewhere come in contact. How it does this without creating a problem is intriguing.

 

[mikeylikesit]

Yes but the RG injection is just if the baby has negative or positive blood type. The injection is used after the first baby, to prevent complications from the same babies antibodies. The mother is injected with it to prevent reactions.

Knowing this RG injection is used to give the mother build up of specific antibodies as not to cause harm when another baby is born with a different, either positive(mom) negative(baby). I think it can cause issues in the mother.

So knowing this the blood has to somehow, somewhere come in contact. How it does this without creating a problem is intriguing.

it can on any baby after the first one cause complications for both the mother and the baby. On a side note the baby gets its antibodies in the form of IgG while in the womb and then it receive supplemental antibodies while it builds up it's immune system after birth from the mothers brest milk containing IgA's. this is why women who do not breast feed run a higher risk of their babies being more prone to illness whilst in the infant phases for the first 3 months at least....i hsvr no idea while i elsborated on this, but i felt like pushing the info out there.