Why left arm pain with a MI?

[Cindigo]

The internets were coming up with either referred pain, or blocked vessels on that side causing pain. With my finely honed hogwarts researching skills, the sites I was finding seemed a little suspect. I was hoping someone here could confirm/deny and give a short explination.

Right now I'm reading the chapter on respitory emergencies and pulmonary edema came up. I'm not exactly sure where the fluid in the lungs would be coming from, the book doesn't really say. I read something about failing kidneys in non cardiac causes, and vessel failure with cardiac events, but I was a bit confused.

 

[JPINFV]

Cardiac chest pain is from referred pain and doesn't have to be the left arm. Basically the visceral sensory nerves mapped the same as the dermatomes. The current theory is basically the body takes the visceral sensory input and maps it along the other areas that enter the spinal cord at the same location. So the cardiac visceral afferent (afferent = sensory, efferent = motor or visceral control) enters at T1-5, so you'll normally get referred pain in the T1-5 dermatomes. There's also the entire concept in ostopathic medicine of visceral somatics (basically tenderness or other somatic changes) along the same lines that, in my opinion, is just a cute curiosity.

Pulmonary edema in cardiac issues such as left sided failure comes from an increase in pulmonary venous pressure. A decrease in lymph drainage or decrease in serum osmolality (thus losing osmotic pressure, but this would not just be limited to the lungs) are other causes of pulmonary edema.

 

[Cindigo]

Cardiac chest pain is from referred pain and doesn't have to be the left arm. Basically the visceral sensory nerves mapped the same as the dermatomes. The current theory is basically the body takes the visceral sensory input and maps it along the other areas that enter the spinal cord at the same location. So the cardiac visceral afferent (afferent = sensory, efferent = motor or visceral control) enters at T1-5, so you'll normally get referred pain in the T1-5 dermatomes. There's also the entire concept in ostopathic medicine of visceral somatics (basically tenderness or other somatic changes) along the same lines that, in my opinion, is just a cute curiosity.

Pulmonary edema in cardiac issues such as left sided failure comes from an increase in pulmonary venous pressure. A decrease in lymph drainage or decrease in serum osmolality (thus losing osmotic pressure, but this would not just be limited to the lungs) are other causes of pulmonary edema.

Thanks so much. Really good explanation and some great concepts for more research. We vaguely touched on dermatomes a few weeks ago in class. If I ever go bananas and get a full body tattoo.....that's going to be it.

 

[Squad51]

Cardiac chest pain is from referred pain and doesn't have to be the left arm. Basically the visceral sensory nerves mapped the same as the dermatomes. The current theory is basically the body takes the visceral sensory input and maps it along the other areas that enter the spinal cord at the same location. So the cardiac visceral afferent (afferent = sensory, efferent = motor or visceral control) enters at T1-5, so you'll normally get referred pain in the T1-5 dermatomes. There's also the entire concept in ostopathic medicine of visceral somatics (basically tenderness or other somatic changes) along the same lines that, in my opinion, is just a cute curiosity.

Pulmonary edema in cardiac issues such as left sided failure comes from an increase in pulmonary venous pressure. A decrease in lymph drainage or decrease in serum osmolality (thus losing osmotic pressure, but this would not just be limited to the lungs) are other causes of pulmonary edema.

Awesome explanation!

If I can just add left arm pain of cardiac origin usually stops at the wrist. Left arm pain of other etiology typically goes all the way into the finger tips or hands. I don't have any scientific data to back this up. Just been my experience.

 

[JPINFV]

Look where T1 and 2 is...

 

[Handsome Robb]

I had an explanation but JP's blows mine out of the water.

As for referred pain of cardiac origin you have to be careful, especially in women. They don't usually present like the book says. Could be jaw pain, epigastric "heartburn" type pain, abdominal pain. Despite what the book says just because someone's chest pain is reproducible by palpation or deep inspiration doesn't mean it isn't of a cardiac etiology.

 

[JPINFV]

There are somethings that osteopathic medicine does well... like surface anatomy and the mechanisms behind pain. Also, the biggest thing to remember is that typical cardiac pain is actually atypical.

 

[Handsome Robb]

Also, the biggest thing to remember is that typical cardiac pain is actually atypical.

So very true.

 

[Hunter]

I had an explanation but JP's blows mine out of the water.

+1000

As for referred pain of cardiac origin you have to be careful, especially in women. They don't usually present like the book says. Could be jaw pain, epigastric "heartburn" type pain, abdominal pain. Despite what the book says just because someone's chest pain is reproducible by palpation or deep inspiration doesn't mean it isn't of a cardiac etiology.

Also don't forgot diabetics can present in the same way, seen a patient with nose pain once who was having a Major MI, over here some of the departments any pain from nose to belly button anterior or posterior get a 12 lead.

 

[Cindigo]

Right now I'm reading the chapter on respitory emergencies and pulmonary edema came up. I'm not exactly sure where the fluid in the lungs would be coming from, the book doesn't really say. I read something about failing kidneys in non cardiac causes, and vessel failure with cardiac events, but I was a bit confused.

Someday I will learn to finish the chapter before I start asking questions. Surprisingly, it answered most of the edema questions that the first 3/4ths brought up.

:wacko: Sitting here reading by myself isn't nearly as fun as screwing around on the internet.

 

[MSDeltaFlt]

The internets were coming up with either referred pain, or blocked vessels on that side causing pain. With my finely honed hogwarts researching skills, the sites I was finding seemed a little suspect. I was hoping someone here could confirm/deny and give a short explination.

Right now I'm reading the chapter on respitory emergencies and pulmonary edema came up. I'm not exactly sure where the fluid in the lungs would be coming from, the book doesn't really say. I read something about failing kidneys in non cardiac causes, and vessel failure with cardiac events, but I was a bit confused.

Yeah, cardiac chest pain being felt in the left arm and the left jaw makes sense. Heart's on the left side - dermatomes. Pain felt down the left arm. Pretty straightforward there.

As far as fluid in the lungs from pulmonary edema is just as straightforward, that's from CHF, or left heart failure. The left ventricle becomes too weak to handle the blood flow pumping against the distal vascular resistance of the exacerbated hypertensive pt and fails like every other muscle would when they hit failure. The rest of the heart hasn't failed in comparison (there's a difference between peripheral hypertension and pulmonary hypertension) and keeps pumping blood into left ventricle that can't handle the workload and blood gets backed up up stream and takes the path of least resistance: the lungs. When red blood mixes with the normally clear pulmonary fluid it becomes pink and frothy.

 

[mycrofft]

Before I got onto meds, and occasional still, if I stifle a good deep sneeze I get a deep cramping pain at the c4-c5 areas, takes about two seconds to come on and four or five to go away. I don't stifle sneezes anymore.

Pulmonary edema...there are other causes besides heart failure. Again, speaking form experience (as a young man this time), had to go into a crawlspace without my air pak, and six hours later chest got tight and a little rales-y, then it resolved within a couple hours. There was smoke from overheated electrical insulation present, so likely HCl, vaporized distillates from overheated PVC, and whatever adsorbed onto the micro particles in the visible smoke.

PS: left sided heart equals left sided pain is not a no-brainer, the heart per se is not causing the pain to be perceived on the left. Some folks perceive right sided pain, or bilateral or circumferential pain.