No abstract

our aim was to identify optimal cardiopulmonary exercise testing (cpet) threshold values that distinguish disease severity progression in patients with co-existing systolic heart failure (Hf) and chronic obstructive pulmonary disease (COPD), and to evaluate the impact of the cut-off determined on the prognosis of hospitalizations. We evaluated 40 patients (30 men and 10 woman) with HF and copD through pulmonary function testing, doppler echocardiography and maximal incremental cpet on a cycle ergometer. Several significant CPET threshold values were identified in detecting a forced expiratory volume in 1 second (FEV 1 ) < 1.6 L: 1) oxygen uptake efficiency slope (OUES) < 1.3; and 2) circulatory power (cp) < 2383 mmHg.mlO 2 .kg −1 . CPET significant threshold values in identifying a left ventricular ejection fraction (LVef) < 39% were: 1) OUES: < 1.3; 2) CP < 2116 mmHg.mlO 2 .kg −1 . min −1 and minute ventilation/carbon dioxide production (V̇e/Vċo 2 ) slope>38. The 15 (38%) patients hospitalized during follow-up (8 ± 2 months). In the hospitalizations analysis, LVEF < 39% and FEV 1 < 1.6, OUES < 1.3, CP < 2116 mmHg.mlO 2 .kg −1 .min −1 and V̇e/Vċo 2 > 38 were a strong risk predictor for hospitalization (p ≤ 0.050). The CPET response effectively identified worsening disease severity in patients with a Hf-copD phenotype. LVef, feV 1, CP, OUES, and the V̇e/Vċo 2 slope may be particularly useful in the clinical assessment and strong risk predictor for hospitalization.

Exercise intolerance is the hallmark consequence of advanced chronic heart failure (HF). The six-minute step test (6MST) has been considered an option for the six-minute walk test because it is safe, inexpensive, and can be applied in small places. However, its reliability and concurrent validity has still not been investigated in participants with HF with reduced ejection fraction (HFrEF). Clinically stable HFrEF participants were included. Reliability and error measurement were calculated by comparing the first with the second 6MST result. Forty-eight hours after participants underwent the 6MST, they were invited to perform a cardiopulmonary exercise test (CPET) on a cycle ergometer. Concurrent validity was assessed by correlation between number of steps and peak oxygen uptake (V O 2 peak) at CPET. Twenty-seven participants with HFrEF (60 ± 8 years old and left ventricle ejection fraction of 41±6%) undertook a mean of 94±30 steps in the 6MST. Intra-rater reliability was excellent for 6MST (ICC=0.9), with mean error of 4.85 steps and superior and inferior limits of agreement of 30.6 and -20.9 steps, respectively. In addition, strong correlations between number of steps and CPET workload (r=0.76, Po0.01) and peak V O 2 (r=0.71, Po0.01) were observed. From simple linear regression the following predictive equations were obtained with 6MST results: V O 2 peak (mL/min) = 350.22 + (7.333 Â number of steps), with R 2 =0.51, and peak workload (W) = 4.044 + (0.772 Â number of steps), with R 2 =0.58. The 6MST was a reliable and valid tool to assess functional capacity in HFrEF participants and may moderately predict peak workload and oxygen uptake of a CPET.

Purpose: Chronic obstructive pulmonary disease (COPD) and abnormalities of left ventricular (LV) geometry often coexist. This study aimed to verify whether LV geometry is associated with airflow obstruction, functional capacity, and grip strength in COPD patients. Methods: Thirty-seven COPD patients (GOLD II, III, and IV) were allocated to three groups according to LV geometry as assessed by transthoracic echocardiography: normal (n = 13), concentric LV remodeling (n = 8), and concentric LV hypertrophy (LVH) (n = 16). Lung function was assessed using spirometry. The Duke Activity Status Index (DASI) was used to estimate functional capacity, and grip strength measurement was performed using a hydraulic hand dynamometer. Results: The concentric LVH group presented lower DASI scores (P = .045) and grip strength (P = .006) when compared with the normal group. Correlations analysis showed the following: relative wall thickness negatively correlated with forced expiratory volume in the first second (r = −0.380; P = .025) and DASI score (r = −0.387, P = .018); LV mass index negatively correlated with grip strength (r = −0.363, P = .038). Conclusions: In COPD patients, LV geometry is associated with airflow limitation, functional capacity, and grip strength. Specifically, concentric LV remodeling is associated with increased airflow limitation and decreased functional capacity whereas increased LV mass is associated with decreased grip strength.

The objective of this study was to investigate the impact of chronic obstructive pulmonary disease (COPD)-heart failure (HF) coexistence on linear and nonlinear dynamics of heart rate variability (HRV). Forty-one patients (14 with COPD-HF and 27 HF) were enrolled and underwent pulmonary function and echocardiography evaluation to confirm the clinical diagnosis. Heart rate (HR) and R-R intervals (iRR) were collected during active postural maneuver (APM) [supine (10 min) to orthostasis (10 min)], respiratory sinus arrhythmia maneuver (RSA-M) (4 min), and analysis of frequency domain, time domain, and nonlinear HRV. We found expected autonomic response during orthostatic changes with reduction of mean iRR, root mean square of successive differences between heart beats (RMSSD), RR tri index, and high-frequency [HF (nu)] and an increased mean HR, low-frequency [LF (nu)], and LF/HF (nu) compared with supine only in HF patients (Po0.05). Patients with COPD-HF coexistence did not respond to postural change. In addition, in the orthostatic position, higher HF nu and lower LF nu and LF/HF (nu) were observed in COPD-HF compared with HF patients. HF patients showed an opposite response during RSA-M, with increased sympathetic modulation (LF nu) and reduced parasympathetic modulation (HF nu) (Po0.05) compared with COPD-HF patients. COPD-HF directly influenced cardiac autonomic modulation during active postural change and controlled breathing, demonstrating an autonomic imbalance during sympathetic and parasympathetic maneuvers compared with isolated HF.