Lead researcher Alicia E. Meuret, a psychologist at Southern Methodist University in Dallas, says the study is based on 24-hour monitoring of panic sufferers while they went about their daily activities. Portable recorders captured changes in respiration, heart rate and other bodily functions, Meuret says.
The researchers captured panic attacks as they occurred and discovered waves of significant physiological instability for at least 60 minutes before patients' awareness of the panic attacks, Meuret says.
The findings, published in the journal Biological Psychiatry, suggest sufferers of panic attacks may be highly sensitive to -- but unaware of -- an accumulating pattern of subtle physiological instabilities that occur before an attack. The monitoring data also showed patients were hyperventilating on a chronic basis.