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Contribution of group III and IV muscle afferents to ventilatory control during submaximal exercise in heart failure
Author(s) -
Olson Thomas P,
Joyner Michael J,
Eisenach John H,
Curry Timothy B,
Johnson Bruce D
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1146.1
Subject(s) - medicine , fentanyl , chemoreceptor , anesthesia , heart failure , cardiology , microneurography , tidal volume , respiratory minute volume , ventilatory threshold , ventilation (architecture) , baroreflex , heart rate , vo2 max , respiratory system , blood pressure , mechanical engineering , receptor , engineering
Background Heart failure (HF) causes abnormal ventilatory responses to exercise which are inked to poor prognosis. We examined the impact of blocking fine afferents from locomotor muscles on exercise ventilatory efficiency in HF. Methods 9 HF patients (60±6yrs, LVEF 27±6%) and 9 healthy controls (63±7yrs) underwent two 5 min cycling sessions at 65% peak workload with and without intrathecal fentanyl. VO 2 , VCO 2 , V E , breathing frequency (fb), tidal volume (V T ), and chemoreceptor sensitivity (CO 2 rebreathe) were measured. Results Fentanyl did not influence exercise VO 2 in either group (HF=1.5±0.3 vs 1.5±0.3 L/min, control=1.7±0.4 vs 1.7±0.5 L/min). V E was lower with fentanyl in HF but not control (−12.3±7.1 vs 0.8±6.2%, p<0.001) due to lower fb (−10.5±4.6 vs 0.5±7.1%, p<0.01) with no change in V T (−1.2±9.4 vs 0.4±5.7%, p=0.67). V E /VCO 2 improved during exercise with fentanyl in HF but not in controls (−14.8±7.1 vs ‐ 0.5±7.0, p<0.01). Fentanyl did not influence chemoreceptor sensitivity in either group. Conclusion Blocking group III and IV afferent feedback from the locomotor muscles during exercise improves ventilatory efficiency in HF. NIH/NCRR grant KL2‐RR024151.