How a Irritated Focus Begin

[hefner33]

I know their are the normal responses such as stress, heart disease, etc but what physiologically happens to the hearts focus for them to become iriitated and cause arrythmias. Im kinda really interested in this stuff ever since inheriting premature beats but it seems odd when i see Drs respond with "sometimes there is no reason". How can that/those focus decide they want to start firing chronically.  Ive looked around but didnt really see much info and wondered if any one here had some insight.

Thanks

[hefner33]

Thanks.

It seems that since it is "very common" doctors would understand it more

[tommy1357]

If you are interested in the reasons for automaticity of the heart, look up and read about "action potentials" of the heart.  Certain areas of the heart naturally have automaticity...  the sinus node, av node and his purkinje system.  Normal myocardial cells generally don't and need to receive electrical stimulus in order to depolarize. Why some cells develop this automaticity that shouldnt have it (pac's pvc's) is not well understood.

[DeltaDawn23]

I think some people are just more prone to it.  I have always had pvs's, pac's and it seemed normal to me.  My undiagnosed sleep apnea played a part in my afib, as well as extreme anxiety, vagus nerver irritation.