I was hoping some of you cardiac folks could help me. I am in Physiology and we just finished a unit on the cardiovascular system. I came up with a question my instructor couldnt answer
Our text was discussing the SA node and how it is the pacemaker for the heart. The text also said other cells in the heart are capable of generating action potentials as well. My question is: when a patient is in PEA, is this what is happening? Are these other cells trying to fire action potentials and take over for the SA node? Our text isnt clear on the subjuect and I have been looking around in Taber's and on some sites but so far all I have found is how to treat PEA, definitions of Pea, etc. I am curious so let me know. Believe it or not, my physiology instructor didnt know what PEA was
I couldnt believe it.
Mar 20, '04
During PEA, the heart's electrical system can very well be functioning properly. Something else is keeping the heart from beating! Could be cardiac tampenode (sp?) where fluid within the cardiac sack is literally preventing the heart from beating. It could be a pulmonary embolism where where blood is prevented to to into the heart by a HUGE blood clot(s) in the lung. It could be a drug overdose. It could be a significant electrolye imbalance.
Check out the American Heart Association's Advanced Cardiac Life Support (ACLS) text books. They do a fairly good job explaining PEA.
Remember: PEA is a life threatening situation. The heart's electrical system may very well be working just fine as evidenced by an EKG. But the heart is NOT pumping blood!!!
Hope this is helpful!
P. S. I've seen and dealt with PEA a few times. It's wierd and scary. You see the cardiac rhythms on the monitor, but you can't feel the freakin' pulse! In all the cases that I dealt with PEA, it involved a huge pulmonary embolism. Despite CPR (well performed chest compressions), one could NOT feel the pulse! The ENTIRE cardiao/pulmonary/peripheral vasculature was blocked by a huge clot(s). Very wierd! Very scary! Very sad!
Last edit by Ted on Mar 20, '04