title: Spectral transfer function analysis of respiratory hemodynamic fluctuations predicts end-diastolic stiffness in preserved ejection fraction heart failure.
abstract: Preserved ejection fraction heart failure (HFpEF) diagnosis remains controversial, and invasive left ventricular (LV) hemodynamic evaluation and/or exercise testing is advocated by many. The stiffer HFpEF myocardium may show impaired stroke volume (SV) variation induced by fluctuating LV filling pressure during ventilation. Our aim was to investigate spectral transfer function (STF) gain from end-diastolic pressure (EDP) to indexed SV (SVi) in experimental HFpEF. Eighteen-week-old Wistar-Kyoto (WKY) and ZSF1 lean (ZSF1 Ln) and obese rats (ZSF1 Ob) randomly underwent LV open-chest (OC, n = 8 each group) or closed-chest hemodynamic evaluation (CC, n = 6 each group) under halogenate anesthesia and positive-pressure ventilation at constant inspiratory pressure. Beat-to-beat fluctuations in hemodynamic parameters during ventilation were assessed by STF. End-diastolic stiffness (βi) and end-systolic elastance (Eesi) for indexed volumes were obtained by inferior vena cava occlusion in OC (multibeat) or single-beat method estimates in CC. ZSF1 Ob showed higher EDP spectrum (P < 0.001), higher STF gain between end-diastolic volume and EDP, and impaired STF gain between EDP and SVi compared with both hypertensive ZSF1 Ln and normotensive WKY controls (P < 0.001). Likewise βi was only higher in ZSF1 Ob while Eesi was raised in both ZSF1 groups. On multivariate analysis βi and not Eesi correlated with impaired STF gain from EDP to SVi (P < 0.001), and receiver-operating characteristics analysis showed an area under curve of 0.89 for higher βi prediction (P < 0.001). Results support further clinical testing of STF analysis from right heart catheterization-derived EDP surrogates to noninvasively determined SV as screening/diagnostic tool to assess myocardial stiffness in HFpEF.
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Porto, Portugal;
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Abdellatif
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Porto, Portugal;
authors.forename: Sara
authors.initials: S
authors.lastname: Leite
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Porto, Portugal; Department of Cardiothoracic Surgery, Suez Canal University, Ismailia, Egypt;
authors.forename: Mohamed
authors.initials: M
authors.lastname: Alaa
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Porto, Portugal; Department of Vascular Surgery, Hospital São João, Porto, Portugal;
authors.forename: José
authors.initials: J
authors.lastname: Oliveira-Pinto
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Porto, Portugal; Department of Cardiology, Hospital São João, Porto, Portugal;
authors.forename: Marta
authors.initials: M
authors.lastname: Tavares-Silva
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Porto, Portugal;
authors.forename: Dulce
authors.initials: D
authors.lastname: Fontoura
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Porto, Portugal;
authors.forename: Inês
authors.identifier: http://orcid.org/0000-0003-1937-3782
authors.initials: I
authors.lastname: Falcão-Pires
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Porto, Portugal; Department of Cardiothoracic Surgery, Hospital São João, Porto, Portugal;
authors.forename: Adelino F
authors.initials: AF
authors.lastname: Leite-Moreira
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine, University of Porto, Porto, Portugal; Department of Anesthesiology, Hospital São João, Porto, Portugal aplourenco@yahoo.com.
authors.forename: André P
authors.identifier: http://orcid.org/0000-0002-5756-9535
authors.initials: AP
authors.lastname: Lourenço
mesh_terms: D000818:Animals; D019540:Area Under Curve; D006328:Cardiac Catheterization; D003971:Diastole; D004195:Disease Models, Animal; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D006333:Heart Failure / Q000175:diagnosis* / Q000503:physiopathology; D008955:Models, Cardiovascular; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D012372:ROC Curve; D011921:Rats, Inbred WKY; D011924:Rats, Zucker; D012119:Respiration; D012121:Respiration, Artificial; D012815:Signal Processing, Computer-Assisted; D013318:Stroke Volume; D013997:Time Factors; D016277:Ventricular Function, Left; D017725:Ventricular Pressure
keywords: heart failure with preserved ejection fraction; myocardial stiffness; spectral analysis; spectral transfer function