La prévention des facteurs de risques dans les maladies cardiovasculaires (MCV) est un enjeu de santé publique. Plus particulièrement, les troubles de l’anxiété sont reconnus comme un facteur aggravant dans le développement des MCV. Parmi les traitements non psychotropes, les techniques de relaxation basées sur la respiration profonde ont montré des effets importants sur la gestion de l’anxiété et la variabilité de la fréquence cardiaque. L’objectif de cette étude est de vérifier les effets de la respiration profonde chez des patients à risques cardiovasculaires présentant des troubles anxieux.

À partir d’un protocole expérimental à cas unique, trois participants ont suivi un entraînement à la respiration profonde et ont rempli une série de questionnaires de dépression, d’anxiété et d’évitement cognitif.

Les résultats montrent qu’un entraînement de 4heures à cette technique est nécessaire pour améliorer la santé cardiovasculaire et s’accompagne d’une diminution des troubles de l’anxiété et d’une diminution des scores de certaines sous-échelles du Questionnaire d’évitement cognitif.

Ces résultats confirment les rares études intéressées par les traitements non psychotropes sur la gestion de l’anxiété chez des populations à pathologies cardiovasculaires en montrant que des thérapies brèves, menées dans le cadre de programme de réentraînement à l’effort, peuvent être utiles dans la gestion des troubles de l’anxiété.

The onset of cardiovascular diseases is usually associated with age and risk factors involving individual behaviors (smoking, physical inactivity and/or poor diet) and environmental conditions favoring acquired or genetic individual vulnerabilities (obesity, hypertension, cholesterol or type 2 diabetes). In these contexts, prevention of risk factors is a public health issue. Depression has been recently considered as a major cardiovascular risk factor. Likewise, recent studies have demonstrated that anxiety disorders are as critical as depression in CVD. Patients with cardiovascular disease and anxiety disorder show lower heart rate variability (HRV) than those who do not have anxiety disorders. In the case of CVD with anxiety disorders, non-psychotropic treatments are recommended. Among them, deep-breathing techniques have shown long-term efficacy with a decrease in anxiety disorders and an increase in HRV that is commonly used to account for cardiovascular health. In cardiac rehabilitation programs, this kind of therapy has shown positive effects independent of physical activity effects. However, with this population, deep-breathing techniques have never been used in brief therapy. Current indices of HRV used with normal population are not reliable with a cardiac population and we preferred indices that assess the parasympathetic system (e.g., RMSSD) more directly. The aim of this case study was to assess the reliability of HRV of cardiac patients involved in a deep-breathing intervention. Secondary hypotheses were proposed to determine the impact of the deep-breathing technique on measures of anxiety, depression, and cognitive avoidance. An integrated approach of anxiety proposes to conceive anxiety as a set of emotional, cognitive and biological processes linked to avoidance behaviors.

The use of single-case experimental design (A-B) was preferred in order to take into account the complexity of the context. Three patients (two females and 1 male aged from 54 to 59 years) were recruited to undergo deep-breathing training. Measurements of anxiety, depression and cognitive avoidance were carried out both at the beginning and at the end of treatment therapy that was classified in level one (2hours of deep-breathing training). The protocol employed a breathing frequency of approximately 6 breaths per minute. The patients practiced on their own at least 3 times per day for 5minutes. In order to assess the evolution of HRV using the RMSSD index, between 9 and 12 measures were carried out for each patient.

In order to assess the effectiveness of deep-breathing on HRV on rest and anxiety disorders, we used the statistical approach of Jacobson and Truax (1991) to define meaningful change in psychotherapy research. The results revealed a significant improvement in HRV (RMSSD) indices for two of the three patients (z≈–3.90, d≈–2.91, P<0.01 for patient 2 who trained during 210min and z≈–4.17, d≈–1.54, P<0.01 for patient 3 who trained during 310min). Moreover, for these two patients, scores on the anxiety scale were significantly lower but stayed in critical range of the measure.

An average of four hours of deep-breathing training appears to be sufficient to elicit changes in the activity of parasympathetic system measured by the RMSSD (temporal index) of HRV. However, this training is insufficient to generate change in the psychological variables. This data is interesting insofar as it provides insight into the reliability of HRV indices in patients with CVD and the linkage between physiological and psychological processes that are predicted to interact. Despite good internal validity of these experimental protocols, due to the limited number of participants it is not possible to generalize the results in these populations. However, psychotherapy of level 2 could be more effective in reducing psychological symptoms.