title: Improvement in left intraventricular pressure gradients after aortic valve replacement in aortic stenosis patients.
abstract: What is the central question of this study? Normal diastolic and systolic intraventricular pressure gradients are decreased when left ventricular filling and/or emptying are compromised. We hypothesized that in patients with severe aortic valve stenosis, a condition that interferes with ventricular filling and emptying, those gradients would be disturbed. What is the main finding and its importance? We showed the existence of intraventricular pressure gradients throughout the cardiac cycle in the human left ventricle. Moreover, we demonstrated, for the first time, that diastolic and systolic gradients, which are markers of normal ventricular filling and emptying, respectively, improved in patients with severe aortic valve stenosis immediately after valve replacement. The present study was conducted to characterize left intraventicular pressure gradients, which are markers of normal cardiac function, in patients with severe aortic stenosis, a condition that interferes with ventricular filling and emptying. In 10 patients (four male; mean age 71.3 ± 4.8 years old) undergoing aortic valve replacement, two high-fidelity pressure catheters were inserted inside the cavity of the left ventricle through an apical puncture and positioned in the apex and outflow tract below the aortic valve. Pressures were continuously acquired and gradients calculated as apical minus outflow tract pressure, before and immediately after aortic valve replacement. During early filling, we recorded a negative intraventricular gradient along the basal portion of the left ventricle in the apical direction (-0.82 ± 0.45 mmHg), which increased to -3.97 ± 0.42 mmHg after aortic valve replacement. In late filling, intraventricular flow was now directed towards the outflow tract, with a positive pressure gradient both before (+1.23 ± 0.37 mmHg) and after surgery (+2.12 ± 0.58 mmHg). During systole, before surgery we observed a positive pressure gradient between the apex and outflow tract during both rapid (+1.60 ± 0.21 mmHg) and slow ejection phases (+1.68 ± 0.12 mmHg), whereas after aortic valve replacement the positive gradient (+1.54 ± 0.15 mmHg) during rapid ejection was inverted (-3.92 ± 0.34 mmHg) during the slow ejection phase. We demonstrated that in patients with severe aortic stenosis both diastolic and systolic intraventricular pressure gradients are significantly attenuated but can be restored immediately after aortic valve replacement. The assessment and measurement of intraventricular pressure gradients and their modulation in pathophysiological conditions may provide novel insights into cardiac physiology.
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, Porto, Portugal.|Department of Cardiothoracic Surgery, Centro Hospitalar de Vila Nova de Gaia/Espinho, Rua Conceição Fernandes, Vila Nova de Gaia, Portugal.
authors.forename: Miguel
authors.identifier: 0000-0002-5101-4045
authors.initials: M
authors.lastname: Guerra
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, Porto, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Mendes-Ferreira
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, Porto, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Adão
authors.affiliation: Department of Cardiothoracic Surgery, Centro Hospitalar de Vila Nova de Gaia/Espinho, Rua Conceição Fernandes, Vila Nova de Gaia, Portugal.|Department of Cardiology, Centro Hospitalar de Vila Nova de Gaia/Espinho, Rua Conceição Fernandes, Vila Nova de Gaia, Portugal.
authors.forename: Eulália
authors.initials: E
authors.lastname: Pereira
authors.affiliation: Department of Anesthesiology, Centro Hospitalar de Vila Nova de Gaia/Espinho, Rua Conceição Fernandes, Vila Nova de Gaia, Portugal.
authors.forename: Manuela
authors.initials: M
authors.lastname: Vieira
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, Porto, Portugal.
authors.forename: André P
authors.initials: AP
authors.lastname: Lourenço
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, Porto, Portugal.|Faculty of Nutrition and Food Sciences, University of Porto, Porto, Portugal.
authors.forename: Carmen
authors.initials: C
authors.lastname: Brás-Silva
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, Porto, Portugal.|Department of Cardiothoracic Surgery, Centro Hospitalar São João, Alameda Professor Hernâni Monteiro, Porto, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Bastos
authors.affiliation: Department of Cardiothoracic Surgery, Centro Hospitalar de Vila Nova de Gaia/Espinho, Rua Conceição Fernandes, Vila Nova de Gaia, Portugal.
authors.forename: Luís
authors.initials: L
authors.lastname: Vouga
authors.affiliation: Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, Porto, Portugal.|Department of Cardiothoracic Surgery, Centro Hospitalar São João, Alameda Professor Hernâni Monteiro, Porto, Portugal.
authors.forename: Adelino F
authors.initials: AF
authors.lastname: Leite-Moreira
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000503:physiopathology*; D001024:Aortic Valve Stenosis / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology; D003971:Diastole / Q000502:physiology; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology; D013318:Stroke Volume / Q000502:physiology; D013599:Systole / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology*; D017725:Ventricular Pressure / Q000502:physiology*
keywords: aortic stenosis; intraventricular pressure gradients; left ventricle function