Although Dr. Bert Anderson is now retired, I've kept one of his articles on panic attacks on the Web site because of the effectiveess and merit in the theories he espoused regarding panic attacks. I believe he was a pioneer in this area of anxiety > breathing > panic.
In his own words, "Panic attacks result from what has been called "Hyperventilation Syndrome." Panic attack sufferers all have one thing in common -- they don't breathe properly."
It's a long read, but well worth the time if you suffer from panic attacks and anxiety. You can always click on the "Printable Version" icon (under the article title) and print out a copy to read offline.
Panic Attacks: New Understanding Of Causes And Treatment
by Bert A. Anderson, Ph.D.
You might also want to read the transcript of Dr. Bert Anderson's visit to Power Surge
Dearest