For Roxanne

Hi Roxanne,

I could probably help with the insight if we could communicate more directly. I have to approve all comments before they are published so, if you'd like to leave your email address as a comment, then I'll can get your address then reject the comment so it is not published and privacy could be maintained.

I'm not sure why everyone is dumbfounded because I know we discussed a situation similar to yours in our Cardio Dx class. That is, a block presenting itself upon or after exertion. I've forwarded your comments to the doctor who teaches our Cardio class plus, that's my first class tomorrow morning so I'll be sure to find out more information then.

When you mentioned lightheadedness the word syncope came to mind which has to do with fainting, this is also sometimes referred to as a "Stokes-Adams" episode. While there can be many reasons for a person to experience Stokes-Adams episodes, the most common cause is Sick Sinus Syndrome which has a couple of aka's such as Sinus Arrest or SA Block and P-pulmonale may also be used. When we talk about P-pulmonale we're essentially talking about the right side of your heart which is the pump that sends blood to your lungs. A situation such as COPD or emphysema are the most common conditions associated with P-pulmonale.

Of course, your one cardiologist already mentioned hyper-vagal tone (aka vagotonia, aka a type of parasympatheticotonia) You might want to notice that I made the letter "o" bold faced in parasypatheticotonia, because if you decide to Google that word, there is another very similar word but instead of that letter "o" there is a letter "a" in it's place. When the word is used with an "o" it represents an increase, in this case, an increase in your vagus nerve (which is a parasympathetic nerve). When you see it with a letter "a" then we have a lack of input coming from the parasympathetic nerve (i.e., Carnial Nerve number 10, aka the vagus nerve)

When it comes to the heart, parasympathetic nerves slow the heart down while sympathetic nerves speed it up. However, please don't think a loss of sympathetic innervation would play a role in this condition because the sympathetic nervous system provides exclusive innervation to the ventricles but only minimal innervation to the atria, while the right vagus nerve directly innervates the SA node and the left vagus nerve innervates the VA node.

Also, the sympathetic nerves emanate from your neck (cervical region) and your sacrum while the middle of your spine (predominately the thoracic region) is where your sympathetic nerves emit from the spinal cord. I'm just giving you this bit of neuro-anatomy because if you see a chiropractor then you would want to have him look at your cervical region because that's where your sympathetics are located ....

OK - I'm thinking off the top of my head now about the vagus nerve. There are baroreceptors in your carotid arteries (in your neck) as well as in your aortic arch which contain vagus nerve innervation. ...I guess I'm trying to think of possible mechanics behind your situation. You exercise - bp goes up, you stop, then maybe there's some delay and baroreceptors are ...well, perhaps they are a bit hypersensitive to the pressure and vagal stimulation is elicited which turn the heart rate (via the SA node) down a bit too far.

Incidentally, there's also a hormone release by the right atrium called ANP (atrial natriuretic peptide) which is one of the few hormones the body releases to reduce blood pressure.

I guess I could provide better guesses with a look at a 12 lead EKG. If you have one there should be EKG output for leads I, II & III along a left column followed by leads aVR, aVL and aVF then the right half of the output should be for leads V1, V2, V3, V4, V5 & V6.

along the very bottom would be an output for Lead 2 which traverses the entire bottom of the page. If you look at that Lead II strip, and compare to the picture of the normal EKG I've included with this blog, do you have a bigger than normal P wave? (this could indicate P-pulmonale) or, does your S-wave plummets down deeply? (perhaps an indication of SA block)

I hope this is all somewhat helpful.

I'm kind of reminded of a sign I saw at the first chiropractor I ever visited. It read something to the effect of "if yours is not a chiropractic problem then chiropractic will not help but, if yours is a chiropractic problem then nothing else will help"

If it's not a chiro issue then ischemia of the SA node or drugs may contribute to possible etiology of an SA block. From a chiro standpoint, a subluxation of the cervical spine may be related to this issue.

Again, please consider leaving an email address as a comment (i will NOT publish it) but will use it to get hold of you with my own personal email in case you might want to share an EKG that I could use to consult w/ my cardio dx teacher then provide feedback.

Best wishes,

Scott :)