2024
The casting of invasive cardiopulmonary exercise testing: towards a common goal.
Singh I, Waxman A. The casting of invasive cardiopulmonary exercise testing: towards a common goal. European Respiratory Journal 2024, 64: 2400783. PMID: 38991723, DOI: 10.1183/13993003.00783-2024.Peer-Reviewed Original Research
2023
Exercise Pathophysiology in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Postacute Sequelae of SARS-CoV-2 More in Common Than Not?
Joseph P, Singh I, Oliveira R, Capone C, Mullen M, Cook D, Stovall M, Squires J, Madsen K, Waxman A, Systrom D. Exercise Pathophysiology in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Postacute Sequelae of SARS-CoV-2 More in Common Than Not? CHEST Journal 2023, 164: 717-726. PMID: 37054777, PMCID: PMC10088277, DOI: 10.1016/j.chest.2023.03.049.Peer-Reviewed Original ResearchConceptsMyalgic encephalomyelitis/chronic fatigue syndromeME/CFSChronic fatigue syndromeSARS-CoV-2Fatigue syndromePostacute sequelaeCardiopulmonary exercise testingSystemic blood flowExercise pathophysiologyExertional intoleranceIntractable fatigueExercise testingAcute infectionPostexertional malaiseExercise intoleranceOrthostatic intoleranceVentilatory controlLong-term consequencesBlood flowClinical overlapSuch symptomsIntoleranceSequelaeCOVID-19Syndrome
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 extraction
2020
Systemic vascular distensibility relates to exercise capacity in connective tissue disease
Singh I, Oliveira RKF, Naeije R, Oldham WM, Faria-Urbina M, Waxman AB, Systrom DM. Systemic vascular distensibility relates to exercise capacity in connective tissue disease. Rheumatology 2020, 60: 1429-1434. PMID: 33001175, DOI: 10.1093/rheumatology/keaa510.Peer-Reviewed Original ResearchConceptsCTD patientsSystemic oxygen extractionExercise capacityVascular distensibilityCardiopulmonary diseaseOxygen extractionDecreased exercise capacityStroke volume augmentationReduced exercise capacityCommon clinical manifestationsRadial arterial catheterConnective tissue diseaseAerobic exercise capacityPulmonary vascular distensibilityCardio-pulmonary diseasePressure-flow plotsPulmonary hypertensionCardiopulmonary exerciseHeart failureArterial catheterExercise intoleranceTissue diseaseClinical manifestationsNormal controlsPatients
2019
Right Ventricular-Arterial Uncoupling During Exercise in Heart Failure With Preserved Ejection Fraction Role of Pulmonary Vascular Dysfunction
Singh I, Rahaghi FN, Naeije R, Oliveira RKF, Systrom DM, Waxman AB. Right Ventricular-Arterial Uncoupling During Exercise in Heart Failure With Preserved Ejection Fraction Role of Pulmonary Vascular Dysfunction. CHEST Journal 2019, 156: 933-943. PMID: 31103695, DOI: 10.1016/j.chest.2019.04.109.Peer-Reviewed Original ResearchConceptsEes/EaRV-PA uncouplingPulmonary vascular dysfunctionResistive afterloadHeart failureVascular dysfunctionRight ventricular-pulmonary artery couplingLower pulmonary artery complianceRight ventricular-arterial uncouplingInvasive pulmonary hemodynamicsPulmonary arterial elastanceRV contractile reserveRV pressure waveformsVentricular-arterial uncouplingRight ventricular dysfunctionExercise-induced decreasePulmonary artery complianceExercise-induced increaseGroup of patientsLower peak VOLower stroke volumePeak oxygen consumptionSingle-beat analysisEnd-systolic elastancePVR response