Is cardiac autonomic modulation during upper limb isometric contraction and Valsalva maneuver impaired in COPD patients?

Abstract

PurposeTo evaluate the heart rate variability (HRV) indices and heart rate (HR) responses during isometric contraction (IC) and Valsalva maneuver (VM) in COPD patients.MethodsTwenty-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.ResultsDuring 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 (FEV1) vs RMSSD (P=0.04; r=−0.55), FEV1 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). FEV1 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.ConclusionCOPD 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.

Influence of expiratory positive airway pressure on cardiac autonomic modulation at rest and in submaximal exercise in COPD patients

“…An interesting finding of our study was the association between VEF 1 and parasympathetic and sympathetic modulation, as observed by HF and LF indices during rest with EPAP. Our findings contradict previous studies on different autonomic tests like postural changing, isometric contraction, and during dynamic physical exercise ( 4 , 7 , 27 , 28 ). These findings are consistent with the increased parasympathetic cardiac modulation intimately associated with airway obstruction from the bronchoconstriction of these patients ( 29 ).…”

Markers of cardiovascular autonomic dysfunction predict COPD in middle-aged subjects

“…Thus, a relationship between autonomic nervous system malfunction and COPD is quite plausible from a pathophysiological perspective. Previous research has focused on the occurrence of autonomic dysfunction in manifest COPD, in which patients demonstrate elevated resting heart rate, reduced heart rate variability, reduced baroreflex sensitivity [21] and pathologic responses to the Valsalva manoeuvre [30,31]. A postural SBP decrease was previously reported to predict increased mortality from respiratory diseases in MPP [20].…”