Exercise oxygen uptake efficiency slope independently predicts poor outcome in pulmonary arterial hypertension

Universidade Federal de São Paulo UNIFESP, São Paulo Sch Med EPM, Dept Med, Pulm Vasc Grp, São Paulo, BrazilUniversidade Federal de São Paulo, EPM, Dept Med, Div Resp Dis,Pulm Funct & Clin Exercise Physiol U, São Paulo, BrazilQueens Univ, Dept Med, Div Resp & Crit Care Med, Kingston, ON K7L 3N6, CanadaUniversidade Federal de São Paulo UNIFESP, São Paulo Sch Med EPM, Dept Med, Pulm Vasc Grp, São Paulo, BrazilUniversidade Federal de São Paulo, EPM, Dept Med, Div Resp Dis,Pulm Funct & Clin Exercise Physiol U, São Paulo, BrazilWeb of Scienc

Cardiopulmonary disease as sequelae of long-term COVID-19: Current perspectives and challenges

COVID-19 infection primarily targets the lungs, which in severe cases progresses to cytokine storm, acute respiratory distress syndrome, multiorgan dysfunction, and shock. Survivors are now presenting evidence of cardiopulmonary sequelae such as persistent right ventricular dysfunction, chronic thrombosis, lung fibrosis, and pulmonary hypertension. This review will summarize the current knowledge on long-term cardiopulmonary sequelae of COVID-19 and provide a framework for approaching the diagnosis and management of these entities. We will also identify research priorities to address areas of uncertainty and improve the quality of care provided to these patients

Effects of hyperoxia on the dynamics of skeletal muscle oxygenation at the onset of heavy-intensity exercise in patients with COPD

This study addressed whether hyperoxia (HiOX = 50% O(2)), compared to normoxia, would improve peripheral muscle oxygenation at the onset of supra-gas exchange threshold exercise in patients with chronic obstructive pulmonary disease (COPD) who were not overtly hypoxemic (resting Pa(O2) > 60 mmHg). Despite faster cardiac output and improved blood oxygenation, HiOX did not significantly change pulmonary O(2) uptake kinetics ((V) over dot(o2)p). Surprisingly, however, HiOX was associated with faster fractional O(2) extraction (similar to Delta[deoxy-Hb + Mb] by near-infrared spectroscopy) (p < 0.05). in addition, an overshoot in Delta[deoxy-Hb+ Mb] was found after the initial fast response only in HiOX (7/11 patients) thereby suggesting impaired intra-muscular O(2) delivery (Q(O2)' mv)-to-utilization. These data indicate that, despite improved central O(2) delivery, Q(O2)' mv adapted at a slower rate than muscle (V) over dot(O2) under HiOX in non-hypoxaemic patients with COPD. Our results question the rationale of using supplemental O(2) to improve muscle oxygenation during the transition to high-intensity exercise in this patient sub-population. (C) 2010 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Pulm Funct & Clin Exercise Physiol Unit SEFICE, Div Resp Dis, Dept Med, BR-04020050 São Paulo, BrazilUniv Fed Sao Carlos, Cardiopulm Lab, BR-13560 Sao Carlos, SP, BrazilUniversidade Federal de São Paulo, Pulm Funct & Clin Exercise Physiol Unit SEFICE, Div Resp Dis, Dept Med, BR-04020050 São Paulo, BrazilWeb of Scienc

Kinetics of skeletal muscle O-2 delivery and utilization at the onset of heavy-intensity exercise in pulmonary arterial hypertension

Impaired O-2 delivery relative to O-2 demands at the onset of exercise might influence the response profile of muscle fractional O-2 extraction (congruent to Delta[deoxy-Hb/Mb] by near-infrared spectroscopy) either by accelerating its rate of increase or creating an overshoot'' (OS) in patients with pulmonary arterial hypertension (PAH). We therefore assessed the kinetics of O-2 uptake (V) over dot O-2), Delta[deoxy-Hb/Mb] in the vastus lateralis, and heart rate (HR) at the onset of heavy-intensity exercise in 14 females with PAH (connective tissue disease, IPAH, portal hypertension, and acquired immunodeficiency syndrome) and 11 age-and gender-matched controls. Patients had slower (V) over dot O-2 and HR dynamics than controls (tau(V) over dot O-2 = 62.7 +/- 15.2 s vs. 41.0 +/- 13.8 s and t(1/2) -HR = 61.3 +/- 16.6 s vs. 43.4 +/- 8.8 s, respectively; p < 0.01). No study participant had a significant reduction in oxyhemoglobin saturation. in OS(-) subjects (6 patients and 7 controls), the kinetics of Delta[deoxy-Hb/Mb] relative to (V) over dot O-2 were faster in patients (p = 0.05). Larger area under the OS and slower kinetics (MRT) of the downward component indicated greater O-2 delivery-to-utilization mismatch in OS(+) patients versus OS(+) controls (477.4 +/- 330.0 vs. 78.1 +/- 65.6 a.u. and 74.6 +/- 18.8 vs. 46.0 +/- 17.0 s, respectively; p < 0.05). Resting pulmonary vascular resistance was higher in OS(+) than OS(-) patients (23.1 +/- 12.0 vs. 10.7 +/- 4.0 Woods, respectively; p < 0.05). We conclude that microvascular O-2 delivery-to-utilization inequalities slowed the rate of adaptation of aerobic metabolism at the start of heavy-intensity exercise in women with PAH.Universidade Federal de São Paulo, Paulista Sch Med UNIFESP EPM, Pulm Funct & Clin Exercise Physiol Unit SEFICE, Div Resp,Dept Med, BR-04020050 São Paulo, BrazilUniversidade Federal de São Paulo, Paulista Sch Med UNIFESP EPM, Pulm Funct & Clin Exercise Physiol Unit SEFICE, Div Resp,Dept Med, BR-04020050 São Paulo, BrazilWeb of Scienc