2024
Stiffening of the human proximal pulmonary artery with increasing age
Manning E, Mishall P, Ramachandra A, Hassab A, Lamy J, Peters D, Murphy T, Heerdt P, Singh I, Downie S, Choudhary G, Tellides G, Humphrey J. Stiffening of the human proximal pulmonary artery with increasing age. Physiological Reports 2024, 12: e16090. PMID: 38884325, PMCID: PMC11181131, DOI: 10.14814/phy2.16090.Peer-Reviewed Original ResearchConceptsProximal pulmonary arteriesPulmonary arteryAge-related stiffeningRight ventricular ejection fractionVentricular ejection fractionMean wall thicknessEjection fractionNo significant differenceSystemic circulationLuminal caliberDiffusing capacityArterial stiffeningIncreasing ageSignificant differenceDistensionArteryWall thicknessAdverse effectsWall strainVessel diameterCyclic biaxial strainOrgan donorsAgeMicrostructural remodeling
2022
Pressure‐based estimation of right ventricular ejection fraction
Heerdt PM, Singh I, Elassal A, Kheyfets V, Richter MJ, Tello K. Pressure‐based estimation of right ventricular ejection fraction. ESC Heart Failure 2022, 9: 1436-1443. PMID: 35150211, PMCID: PMC8934966, DOI: 10.1002/ehf2.13839.Peer-Reviewed Original ResearchConceptsRight ventricular ejection fractionCardiac magnetic resonance imagingRight heart catheterizationPulmonary arterial hypertensionMagnetic resonance imagingRV pressure waveformsVentricular ejection fractionRV responseEjection fractionMale PAH patientsCardiac MRI measurementsReceiver operator characteristic curvePressure waveformROC curve analysisClinical reference standardOperator characteristic curveSignificant reductionMeasurements of RVEFPAH patientsArterial hypertensionHeart catheterizationSecondary outcomesStudy cohortLimits of agreementBland-Altman analysis
2021
Impaired systemic oxygen extraction long after mild COVID-19: potential perioperative implications
Heerdt PM, Shelley B, Singh I. Impaired systemic oxygen extraction long after mild COVID-19: potential perioperative implications. British Journal Of Anaesthesia 2021, 128: e246-e249. PMID: 35067364, PMCID: PMC8710396, DOI: 10.1016/j.bja.2021.12.036.Peer-Reviewed Original ResearchPersistent 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 extractionQuantification of Arterial and Venous Morphologic Markers in Pulmonary Arterial Hypertension Using CT Imaging
Rahaghi FN, Nardelli P, Harder E, Singh I, Sánchez-Ferrero GV, Ross JC, San José Estépar R, Ash SY, Hunsaker AR, Maron BA, Leopold JA, Waxman AB, San José Estépar R, Washko GR. Quantification of Arterial and Venous Morphologic Markers in Pulmonary Arterial Hypertension Using CT Imaging. CHEST Journal 2021, 160: 2220-2231. PMID: 34270966, PMCID: PMC8692106, DOI: 10.1016/j.chest.2021.06.069.Peer-Reviewed Original ResearchConceptsExercise pulmonary hypertensionPulmonary arterial hypertensionControl subjectsPulmonary hypertensionSmall vessel volumeArterial hypertensionPulmonary arteryPulmonary vasculatureVascular tortuosityVascular volumeArterial volumePrecapillary pulmonary hypertensionCohort of patientsPulmonary vascular volumeVenous manifestationsThromboembolic diseaseCT angiogramArterial tortuosityHypertensionCT scanVessel volumeHeterogeneous diseasePatientsStudy designArteryImpact of right ventricular work and pulmonary arterial compliance on peak exercise oxygen uptake in idiopathic pulmonary arterial hypertension
Messina CMS, Ferreira EVM, Singh I, Fonseca AXC, Ramos RP, Nery LE, Systrom DM, Oliveira RKF, Ota-Arakaki JS. Impact of right ventricular work and pulmonary arterial compliance on peak exercise oxygen uptake in idiopathic pulmonary arterial hypertension. International Journal Of Cardiology 2021, 331: 230-235. PMID: 33545265, DOI: 10.1016/j.ijcard.2021.01.027.Peer-Reviewed Original ResearchConceptsRV stroke work indexPulmonary arterial hypertensionRight heart catheterizationExercise right heart catheterizationIdiopathic pulmonary arterial hypertensionIdiopathic PAHCardiac outputPA complianceArterial hypertensionRight ventricularDynes/s/Mean pulmonary arterial pressurePeak exercise oxygen uptakePeak stroke volume indexPA wedge pressurePeak cardiac indexPulmonary vascular resistanceStroke volume indexStroke work indexCardiopulmonary exercise testingPulmonary arterial pressurePulmonary arterial complianceRight ventricular workAge-adjusted multivariate modelExercise oxygen uptakeSex-Related Differences in Dynamic Right Ventricular-Pulmonary Vascular Coupling in Heart Failure With Preserved Ejection Fraction
Singh I, Oliveira RKF, Heerdt PM, Pari R, Systrom DM, Waxman AB. Sex-Related Differences in Dynamic Right Ventricular-Pulmonary Vascular Coupling in Heart Failure With Preserved Ejection Fraction. CHEST Journal 2021, 159: 2402-2416. PMID: 33388286, DOI: 10.1016/j.chest.2020.12.028.Peer-Reviewed Original ResearchMeSH KeywordsAgedCardiac CatheterizationEchocardiographyExercise ToleranceFemaleFollow-Up StudiesHeart FailureHeart VentriclesHumansIncidenceMalePulmonary ArteryPulmonary Wedge PressureRetrospective StudiesSex DistributionSex FactorsStroke VolumeSystoleUnited StatesVascular ResistanceVentricular Function, RightVentricular PressureConceptsRV-PA couplingRV-PA uncouplingFemale patientsMale patientsPeak VORV contractilityEjection fractionHeart failureRight ventricular-pulmonary vascular couplingRV-pulmonary arterial couplingAge-matched control subjectsInvasive pulmonary hemodynamicsMaximum incremental exercisePulmonary arterial elastanceRV pressure waveformsPeak exercise capacityRight ventricular dysfunctionSingle-beat analysisEnd-systolic elastanceSex-related differencesPA elastanceRV afterloadVentricular dysfunctionAfterload mismatchContractile impairment
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
Pulmonary Vascular Distensibility and Early Pulmonary Vascular Remodeling in Pulmonary Hypertension
Singh I, Oliveira RKF, Naeije R, Rahaghi FN, Oldham WM, Systrom DM, Waxman AB. Pulmonary Vascular Distensibility and Early Pulmonary Vascular Remodeling in Pulmonary Hypertension. CHEST Journal 2019, 156: 724-732. PMID: 31121149, DOI: 10.1016/j.chest.2019.04.111.Peer-Reviewed Original ResearchConceptsPulmonary arterial hypertensionAerobic exercise capacityExercise pulmonary hypertensionPulmonary hypertensionPulmonary vascular distensibilityExercise capacityUnexplained dyspneaControl subjectsVascular distensibilitySex-matched normal control subjectsInvasive pulmonary hemodynamicsRV pressure curveRV-PA couplingRV-PA uncouplingPulmonary vascular remodelingExercise stress testingEes/EaPeak oxygen consumptionNormal control subjectsPressure-flow plotsArterial hypertensionPulmonary hemodynamicsEjection fractionHeart failureRight ventricularRight 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
2015
A Technique for Bronchoscopic Intubation During High-Flow Nasal Cannula Oxygen Therapy
Berlin D, Singh I, Barjaktarevic I, Friedman O. A Technique for Bronchoscopic Intubation During High-Flow Nasal Cannula Oxygen Therapy. Journal Of Intensive Care Medicine 2015, 31: 213-215. PMID: 25911299, DOI: 10.1177/0885066615582020.Peer-Reviewed Original Research