Complexity Measures of Heart-Rate Variability in Amyotrophic Lateral Sclerosis with Alternative Pulmonary Capacities

• Main Authors: Renata M. M. Pimentel, Celso Ferreira, Vitor Valenti, David M. Garner, Hugo Macedo, Acary S. Bulle Oliveira, Francisco Naildo Cardoso Leitão, Luiz Carlos de Abreu
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Series: Entropy
• Subjects: amyotrophic lateral sclerosis; autonomic nervous system; cardiovascular physiology; motor neuron disease; nonlinear dynamics
• Online Access: https://www.mdpi.com/1099-4300/23/2/159

Objective: the complexity of heart-rate variability (HRV) in amyotrophic lateral sclerosis (ALS) patients with different pulmonary capacities was evaluated. Methods: We set these according to their pulmonary capacity, and specifically forced vital capacity (FVC). We split the groups according to FVC (FVC > 50% (<i>n</i> = 29) and FVC < 50% (<i>n</i> = 28)). In ALS, the presence of an FVC below 50% is indicative of noninvasive ventilation with two pressure levels and with the absence of other respiratory symptoms. As the number of subjects per group was different, we applied the unbalanced one-way analysis of variance (uANOVA1) test after three tests of normality, and effect size by Cohen’s <i>d</i> to assess parameter significance. Results: with regard to chaotic global analysis, CFP4 (<i>p</i> < 0.001; <i>d</i> = 0.91), CFP5 (<i>p</i> = 0.0022; <i>d</i> = 0.85), and CFP6 (<i>p</i> = 0.0009; <i>d</i> = 0.92) were enlarged. All entropies significantly increased. Shannon (<i>p</i> = 0.0005; <i>d</i> = 0.98), Renyi (<i>p</i> = 0.0002; <i>d</i> = 1.02), Tsallis (<i>p</i> = 0.0004; <i>d</i> = 0.99), approximate (<i>p</i> = 0.0005; <i>d</i> = 0.97), and sample (<i>p</i> < 0.0001; <i>d</i> = 1.22). Detrended fluctuation analysis (DFA) (<i>p</i> = 0.0358) and Higuchi fractal dimension (HFD) (<i>p</i> = 0.15) were statistically inconsequential between the two groups. Conclusions: HRV complexity in ALS subjects with different pulmonary capacities increased via chaotic global analysis, especially CFP5 and 3 out of 5 entropies.