Key result
Upper limb isometric contraction in COPD is linked to increased HR and impaired Valsalva recovery.
Why the study?
Does upper limb isometric contraction and Valsalva maneuver alter heart rate variability and heart rate responses in stable moderate to severe COPD patients?
Observational (n=22)
Does upper limb isometric contraction and Valsalva maneuver alter heart rate variability and heart rate responses in stable moderate to severe COPD patients?
Patients with moderate to severe COPD exhibit appropriate initial autonomic responses to isometric contraction and Valsalva maneuver, but show impaired heart rate recovery following the Valsalva maneuver.
Answers are grounded in this paper and cite their sources.
Impaired post-Valsalva heart rate recovery suggests autonomic dysfunction in COPD; hypothesis-generating and should not yet alter practice.
Purpose: To evaluate the heart rate variability (HRV) indices and heart rate (HR) responses during isometric contraction (IC) and Valsalva maneuver (VM) in COPD patients. Methods: Twenty-two stable moderate to severe COPD patients were evaluated. R-R intervals were recorded (monitor Polar ® S810i) during dominant upper limb IC (2 minutes). Stable signals were analyzed by Kubios HRV ® software. Indices of HRV were computed in the time domain (mean HR; square root of the mean squared differences of successive RR intervals [RMSSD] and HRV triangular index [RR tri index]) and in the frequency domain (high frequency [HF]; low frequency [LF] and LF/HF ratio). The HR responses were evaluated at rest, at the peak and at the nadir of the VM (15 seconds). The Valsalva index was also calculated. Results: During IC: time domain indices (mean HR increased [ P =0.001], RMSSD, and RR tri index decreased [ P =0.005 and P =0.005, respectively]); frequency domain indices (LF increased [ P =0.033] and HF decreased [ P =0.002]); associations were found between forced expiratory volume in 1 second (FEV 1 ) vs RMSSD ( P =0.04; r =–0.55), FEV 1 vs HR ( P =0.04; r =–0.48), forced vital capacity (FVC) vs RMSSD ( P =0.05; r =–0.62), maximum inspiratory pressure (MIP) vs HF ( P =0.02; r =0.68). FEV 1 and FVC justified 30% of mean HR. During VM: HR increased ( P =0.01); the nadir showed normal bradycardic response; the Valsalva index was =0.7. Conclusion: COPD patients responded properly to the upper limb IC and to the VM; however, HR recovery during VM was impaired in these patients. The severity of the disease and MIP were associated with increased parasympathetic modulation and higher chronotropic response.
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Goulart et al. (2017) conducted an observational in COPD (n=22). Upper limb isometric contraction and Valsalva maneuver vs. Rest was evaluated on Heart rate variability (HRV) indices and heart rate (HR) responses (p=0.001). Upper limb isometric contraction in COPD patients significantly increased mean heart rate (P=0.001), but heart rate recovery during the Valsalva maneuver was impaired.
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