title: Clinical features of panic patients sensitive to hyperventilation or breath-holding methods for inducing panic attacks.
abstract: Our aim was to compare the clinical features of panic disorder (PD) patients sensitive to hyperventilation or breath-holding methods of inducing panic attacks. Eighty-five PD patients were submitted to both a hyperventilation challenge test and a breath-holding test. They were asked to hyperventilate (30 breaths/min) for 4 min and a week later to hold their breath for as long as possible, four times with a 2-min interval. Anxiety scales were applied before and after the tests. We selected the patients who responded with a panic attack to just one of the tests, i.e., those who had a panic attack after hyperventilating (HPA, N = 24, 16 females, 8 males, mean age +/- SD = 38.5 +/- 12.7 years) and those who had a panic attack after breath holding (BHPA, N = 20, 11 females, 9 males, mean age +/- SD = 42.1 +/- 10.6 years). Both groups had similar (chi(2) = 1.28, d.f. = 1, P = 0.672) respiratory symptoms (fear of dying, chest/pain discomfort, shortness of breath, paresthesias, and feelings of choking) during a panic attack. The criteria of Briggs et al. [British Journal of Psychiatry, 1993; 163: 201-209] for respiratory PD subtype were fulfilled by 18 (75.0%) HPA patients and by 14 (70.0%) BHPA patients. The HPA group had a later onset of the disease compared to BHPA patients (37.9 +/- 11.0 vs 21.3 +/- 12.9 years old, Mann-Whitney, P < 0.001), and had a higher family prevalence of PD (70.8 vs 25.0%, chi(2) = 19.65, d.f. = 1, P = 0.041). Our data suggest that these two groups--HPA and BHPA patients--may be specific subtypes of PD.
authors.affiliation: Laboratório de Pânico e Respiração, Instituto de Psiquiatria, Universidade Federal do Rio de Janeiro, R. Visconde de Pirajá 407/702, 22410-003 Rio de Janeiro, RJ, Brazil. aenardi@novanet.com.br
authors.forename: A E
authors.initials: AE
authors.lastname: Nardi
authors.forename: A M
authors.initials: AM
authors.lastname: Valença
authors.forename: F L
authors.initials: FL
authors.lastname: Lopes
authors.forename: I
authors.initials: I
authors.lastname: Nascimento
authors.forename: M A
authors.initials: MA
authors.lastname: Mezzasalma
authors.forename: W A
authors.initials: WA
authors.lastname: Zin
mesh_terms: D000293:Adolescent; D000328:Adult; D001007:Anxiety / Q000150:complications / Q000523:psychology; D001944:Breath Tests; D005260:Female; D006801:Humans; D006985:Hyperventilation / Q000150:complications* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D016584:Panic Disorder / Q000175:diagnosis / Q000209:etiology*