Exercise intolerance in volume overload heart failure is associated with low carotid body mediated chemoreflex drive
Cargando...
Fecha
2021
Autores
David C. Andrade
Esteban Díaz‑Jara
Camilo Toledo
Karla G. Schwarz
Katherin V. Pereyra
Hugo S. Díaz
Noah J. Marcus
Fernando C. Ortiz
Angélica P. Ríos‑Gallardo
Domiziana Ortolani
Título de la revista
ISSN de la revista
Título del volumen
Editor
Resumen
Mounting an appropriate ventilatory response to exercise is crucial to meeting metabolic demands,
and abnormal ventilatory responses may contribute to exercise-intolerance (EX-inT) in heart failure
(HF) patients. We sought to determine if abnormal ventilatory chemoreflex control contributes
to EX-inT in volume-overload HF rats. Cardiac function, hypercapnic (HCVR) and hypoxic (HVR)
ventilatory responses, and exercise tolerance were assessed at the end of a 6 week exercise
training program. At the conclusion of the training program, exercise tolerant HF rats (HF + EX-T)
exhibited improvements in cardiac systolic function and reductions in HCVR, sympathetic tone, and
arrhythmias. In contrast, HF rats that were exercise intolerant (HF + EX-inT) exhibited worse diastolic
dysfunction, and showed no improvements in cardiac systolic function, HCVR, sympathetic tone,
or arrhythmias at the conclusion of the training program. In addition, HF + EX-inT rats had impaired
HVR which was associated with increased arrhythmia susceptibility and mortality during hypoxic
challenges (~ 60% survival). Finally, we observed that exercise tolerance in HF rats was related to
carotid body (CB) function as CB ablation resulted in impaired exercise capacity in HF + EX-T rats. Our
results indicate that: (i) exercise may have detrimental effects on cardiac function in HF-EX-inT, and (ii)
loss of CB chemoreflex sensitivity contributes to EX-inT in HF.