The Role of Dissociation Between Cardiorespiratory and Metabolic Responses in Angina-Like Chest Pain Panic Patients

Abstract

The present study investigates the differences between panic disorder patients with and without angina-like chest pain. The patients were diagnosed according to DSM-III criteria and were divided into chest-pain and no chest-pain subgroups according to the occurrence of angina-like chest pain during their panic attacks. In the first stage of the study, transcutaneous arterial CO2 tension was recorded at rest, during and after a hyperventilation provocation test in 20 panic patients (8 with chest pain and 12 without chest pain during panic attacks) and 23 matched control persons. In the second stage of the study, panic symptom checklists, panic diary, depression, anxiety and fear questionnaires, and surface integrated EMG were documented in 85 panic patients (43 with chest pain and 42 without chest pain during panic attacks). The resting pCO2 level was significantly lower in panic patients with chest pain compared to the controls and to panic patients without chest pain. The pCO2 level after recovery was also significantly lower in the chest pain panic group than in controls. Further significant differences were identified between the two subgroups of panic patients, although the initial mean anxiety level failed to differentiate between subgroups. The surface integrated EMG and the sum of panic symptom checklist were higher in the chest-pain subgroup. The derealization score and the suicide subscale of Beck Depression Inventory were significantly higher in the no-chest pain group. These results underline the significance of reduction of pCO2 level in panic attacks with angina-like chest pain; that is, the significance of dissociation of cardiorespiratory and metabolic responses in this group of patients. These findings may offer an important link in the understanding of physiological responses in anxiety attacks.