Carotid chemoreflex activity restrains post-exercise cardiac autonomic control in healthy humans and in patients with pulmonary arterial hypertension

Author(s):Show less -

Paula-Ribeiro, Marcelle ^{[1, 2, 3, 4]} ; Ribeiro, Indyanara C. ^{[1, 2, 3]} ; Aranda, Liliane C. ^{[1, 2, 3]} ; Silva, Talita M. ^{[1, 2, 3]} ; Costa, Camila M. ^{[2, 3]} ; Ramos, Roberta P. ^{[2, 3]} ; Ota-Arakaki, Jaquelina S. ^{[2, 3]} ; Cravo, Sergio L. ^[1] ; Nery, Luiz E. ^{[2, 3]} ; Stickland, Michael K. ^[5] ; Silva, Bruno M. ^{[1, 2, 3, 4]}

Affiliation

^[1] Univ Fed Sao Paulo, Dept Physiol, Sao Paulo, SP - Brazil

^[2] Univ Fed Sao Paulo, Dept Med, Div Resp Dis, Pulm Vasc Grp, Sao Paulo, SP - Brazil

^[3] Univ Fed Sao Paulo, Dept Med, Div Resp Dis, Pulm Funct & Clin Exercise Physiol Unit, Sao Paulo, SP - Brazil

^[4] Fed Univ Sao Paulo UNIFESP, Dept Med, Postgrad Program Translat Med, Sao Paulo, SP - Brazil

^[5] Univ Alberta, Div Pulm Med, Edmonton, AB - Canada

• Document type: Journal article
• Source: JOURNAL OF PHYSIOLOGY-LONDON; v. 597, n. 5, p. 1347-1360, MAR 1 2019.
• Web of Science Citations: 0

Abstract

Dysfunction of post-exercise cardiac autonomic control predicts mortality, but its underlying mechanisms remain unclear. We tested whether carotid chemoreflex activity restrains post-exercise cardiac autonomic control in healthy adults (HA), and whether such restraint is greater in patients with pulmonary arterial hypertension (PAH) who may have both altered carotid chemoreflex and altered post-exercise cardiac autonomic control. Twenty non-hypoxaemic patients with PAH and 13 age- and sex-matched HA pedalled until 90% of peak work rate observed in a symptom-limited ramp-incremental exercise test. Recovery consisted of unloaded pedalling for 5min followed by seated rest for 6min. During recovery, subjects randomly inhaled either 100% O-2 (hyperoxia) to inhibit the carotid chemoreceptor activity, or 21% O-2 (normoxia) as control. Post-exercise cardiac autonomic control was examined via heart rate (HR) recovery (HRR; HR change after 30, 60, 120 and 300s of recovery, using linear and non-linear regressions of HR decay) and HR variability (HRV; time and spectral domain analyses). As expected, the PAH group had higher carotid chemosensitivity and worse post-exercise HRR and HRV than HA. Hyperoxia increased HRR at 30, 60 and 120s and absolute spectral power HRV in both groups. Additionally, hyperoxia resulted in an accelerated linear HR decay and increased time domain HRV during active recovery only in the PAH group. In conclusion, the carotid chemoreceptors restrained recovery of cardiac autonomic control from exercise in HA and in patients with PAH, with the restraint greater for some autonomic indexes in patients with PAH. (AU)

• FAPESP's process: 15/22198-2 - Tonic contribution of the peripheral chemoreflex to vagal control of the heart at rest, Orthostatism and recovery from exercise in patients with pulmonary arterial hypertension
• Grantee: Marcelle de Paula Ribeiro
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 16/23622-5 - The contribution of peripheral chemoreflex to the vagal control of the heart during recovery from exercise in healthy subjects
• Grantee: Indyanara Cristina Ribeiro
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 14/24294-6 - Tonic contribution of the peripheral chemoreflex to the vagal control of the heart at rest and recovery from exercise in patients with chronic heart failure
• Grantee: Bruno Moreira Silva
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/01155-6 - Cardiorespiratory responses mediated by the interaction between the peripheral chemoreflex and the muscle mechanoreflex in healthy humans
• Grantee: Talita Miranda Silva
• Support Opportunities: Scholarships in Brazil - Master