2024
The metabolic and physiologic impairments underlying long COVID associated exercise intolerance
Leitner B, Joseph P, Quast A, Ramirez M, Heerdt P, Villalobos J, Singh I. The metabolic and physiologic impairments underlying long COVID associated exercise intolerance. Pulmonary Circulation 2024, 14: e70009. PMID: 39544193, PMCID: PMC11560803, DOI: 10.1002/pul2.70009.Peer-Reviewed Original ResearchPeak VO<sub>2</sub>Long COVID patientsCOVID patientsReduced peak VOSeverity of SARS-CoV-2 infectionSystemic oxygen extractionSARS-CoV-2 infectionLong COVIDArterial blood samplesQuantitative metabolomicsPeak VOVenous lactateCardiac outputImpaired mitochondrial ATP productionMild infectionExercise capacityPatientsMitochondrial ATP productionExercise intoleranceArteriovenous gradientBlood samplesOxygen extractionDependent mannerMetabolomicsPhysiological impairment
2023
Proteomic profiling demonstrates inflammatory and endotheliopathy signatures associated with impaired cardiopulmonary exercise hemodynamic profile in Post Acute Sequelae of SARS‐CoV‐2 infection (PASC) syndrome
Singh I, Leitner B, Wang Y, Zhang H, Joseph P, Lutchmansingh D, Gulati M, Possick J, Damsky W, Hwa J, Heerdt P, Chun H. Proteomic profiling demonstrates inflammatory and endotheliopathy signatures associated with impaired cardiopulmonary exercise hemodynamic profile in Post Acute Sequelae of SARS‐CoV‐2 infection (PASC) syndrome. Pulmonary Circulation 2023, 13: e12220. PMID: 37091121, PMCID: PMC10113513, DOI: 10.1002/pul2.12220.Peer-Reviewed Original ResearchInvasive cardiopulmonary exercise testPASC patientsPost-acute sequelaeAcute sequelaeInfection syndromeUnexplained exertional intoleranceCardiopulmonary exercise testSystemic oxygen deliveryPersistent inflammatory stateVenous blood plasmaExertional intolerancePeak exerciseEndothelial dysfunctionHemodynamic profileInflammatory stateExercise testFibrotic processPathophysiological hallmarkAberrant protein expressionExpression of proteinsOxygen deliveryOxygen extractionProteomic profilingPatientsPhysiologic responses
2021
Persistent Exertional Intolerance After COVID-19 Insights From Invasive Cardiopulmonary Exercise Testing
Singh I, Joseph P, Heerdt PM, Cullinan M, Lutchmansingh DD, Gulati M, Possick JD, Systrom DM, Waxman AB. Persistent Exertional Intolerance After COVID-19 Insights From Invasive Cardiopulmonary Exercise Testing. CHEST Journal 2021, 161: 54-63. PMID: 34389297, PMCID: PMC8354807, DOI: 10.1016/j.chest.2021.08.010.Peer-Reviewed Original ResearchConceptsInvasive cardiopulmonary exercise testingCardiopulmonary exercise testingCardiopulmonary diseaseExercise testingControl participantsPeak VOExertional limitationCOVID-19Greater ventilatory inefficiencyPeak cardiac indexSex-matched control participantsCohort of patientsSystemic oxygen extractionDead space ventilationOnly mild symptomsExertional intoleranceCardiac indexPulmonary hemodynamicsAcute infectionVentilatory inefficiencyExercise intolerancePathophysiologic mechanismsMild symptomsHyperventilatory responseOxygen extractionInsights From Invasive Cardiopulmonary Exercise Testing of Patients With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome
Joseph P, Arevalo C, Oliveira RKF, Faria-Urbina M, Felsenstein D, Oaklander AL, Systrom DM. Insights From Invasive Cardiopulmonary Exercise Testing of Patients With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. CHEST Journal 2021, 160: 642-651. PMID: 33577778, PMCID: PMC8727854, DOI: 10.1016/j.chest.2021.01.082.Peer-Reviewed Original ResearchConceptsSmall fiber neuropathyRight atrial pressurePostural orthostatic tachycardiaMyalgic encephalomyelitis/chronic fatigue syndromeCardiopulmonary exercise testingChronic fatigue syndromeExertional intoleranceExercise testingFatigue syndromeControl subjectsOxygen extractionInvasive cardiopulmonary exercise testingLow right atrial pressureME/CFS criteriaHigh pulmonary blood flowME/CFS patientsPeripheral oxygen extractionSmall fiber pathologyPulmonary blood flowSystemic oxygen extractionCardiac returnIntrinsic heartNeurovascular dysregulationRight shuntingCFS patients