A5059422015- Cardiac Valve Diseases and Treatments
- Infective Endocarditis Diagnosis and Management
- Cardiac Imaging and Diagnostics
- Cardiovascular Function and Risk Factors
- Cardiac Structural Anomalies and Repair
- Aortic Disease and Treatment Approaches
- Cardiac Arrhythmias and Treatments
- Atrial Fibrillation Management and Outcomes
- Cardiac pacing and defibrillation studies
- Cardiac, Anesthesia and Surgical Outcomes
- Heart Rate Variability and Autonomic Control
- Coronary Interventions and Diagnostics
- Pulmonary Hypertension Research and Treatments
- Cardiovascular and exercise physiology
- Obstructive Sleep Apnea Research
- Advanced MRI Techniques and Applications
- Cardiomyopathy and Myosin Studies
- Congenital Heart Disease Studies
- Cardiac tumors and thrombi
- Heart Failure Treatment and Management
- Advanced X-ray and CT Imaging
- Radiation Dose and Imaging
- Ultrasound in Clinical Applications
- Cardiovascular and Diving-Related Complications
- Aortic aneurysm repair treatments
University of Ottawa
2016-2025
University of Minnesota Rochester
2022
Ollscoil na Gaillimhe – University of Galway
2021
Karolinska University Hospital
2021
Karolinska Institutet
2021
Royal Brompton Hospital
2021
VA Palo Alto Health Care System
2021
Stanford University
2021
Institut Universitaire de Cardiologie et de Pneumologie de Québec
2010-2020
Ottawa Heart Institute
2007-2019
Only limited data on the rate of hemodynamic progression and predictors outcome in asymptomatic patients with valvular aortic stenosis (AS) are available.In 123 adults (mean age, 63 +/- 16 years) AS, annual clinical, echocardiographic, exercise were obtained prospectively follow-up 2.5 1.4 years). Aortic jet velocity increased by 0.32 0.34 m/s per year mean gradient 7 mm Hg year; valve area decreased 0.12 0.19 cm2 year. Kaplan-Meier event-free survival, end points defined as death (n = 8) or...
Patients with severe aortic stenosis and reduced left ventricular ejection fraction (LVEF) have a poor prognosis conservative therapy but high operative mortality when treated surgically. Recently, transcatheter valve implantation (TAVI) has emerged as an alternative to surgical replacement (SAVR) for patients considered at or prohibitive risk. The objective of this study was compare TAVI SAVR respect postoperative recovery LVEF in LV systolic function.Echocardiographic data were...
We sought to investigate the use of a new parameter, projected effective orifice area (EOAproj) at normal transvalvular flow rate (250 mL/s), better differentiate between truly severe (TS) and pseudo-severe (PS) aortic stenosis (AS) during dobutamine stress echocardiography (DSE). Changes in various parameters severity have been used TS PS AS DSE. However, magnitude these changes lacks standardization because they are dependent on variable change occurring DSE.The EOAproj from was...
Background— Patients with low-flow, low-gradient aortic stenosis have a poor prognosis conservative therapy but high operative mortality if treated surgically. Recently, we proposed new index of severity derived from dobutamine stress echocardiography, the projected valve area at normal transvalvular flow rate, as superior to other conventional indices differentiate true-severe pseudosevere stenosis. The objective this study was identify determinants survival, functional status, and change...
Background— Recent studies have demonstrated increased left ventricular contractility with cardiac resynchronization therapy (CRT) using atriobiventricular stimulation. This study evaluated the effect of CRT on myocardial oxidative metabolism and efficiency. Methods Results— Eight patients New York Heart Association functional class III-IV congestive heart failure were studied during atrial pacing (control) stimulation at same rate. The monoexponential clearance rate [ 11 C]acetate (k mono )...
BACKGROUND Valve areas derived by the Gorlin formula have been observed to vary with transvalvular volume flow rate. Continuity equation valve calculated from Doppler-echo data become a widely used alternate index of stenosis severity, but it is unclear whether continuity also This study was designed investigate effects changing rate on aortic using both and in model chronic valvular stenosis. METHODS AND RESULTS Using canine which anatomy hemodynamics are similar those degenerative...
Transcatheter aortic valve replacement (TAVR) as an alternative to surgical (SAVR) has profoundly changed the management of patients with stenosis (AS). Large unbiased nationwide data regarding TAVR implementation, impact on SAVR and their respective outcomes are scarce.Based a French administrative hospital-discharge database, we collected all consecutive replacements (AVRs) performed in France for AS between 2007 2019 [106 253 isolated (49%), 46 514 combined (21%), 65 651 (30%)]. The...
The prognostic value of B-type natriuretic peptide (BNP) is unknown in low-flow, low-gradient aortic stenosis (AS). We sought to evaluate the relationship between AS and rest, stress hemodynamics, clinical outcome.BNP was measured 69 patients with low-flow (indexed effective orifice area < 0.6 cm2/m2, mean gradient or = 40 mm Hg, left ventricular ejection fraction 40%). All underwent dobutamine echocardiography were classified as truly severe pseudosevere by their projected at normal flow...
Background— Concomitant functional mitral regurgitation (FMR) in patients undergoing aortic valve replacement (AVR) is frequently not corrected because it may improve after AVR; however, data supporting this assumption are sparse. We ascertained the impact of clinical and echocardiographic parameters on outcome with or without concomitant FMR at time AVR. Methods Results— Clinical follow-up was performed 848 who underwent AVR 1990. Risk factors for mortality a composite heart failure (CHF)...
The long-term outcomes of patients with low-gradient aortic stenosis (LGAS) after valve replacement (AVR) are poorly defined. purpose this study was to define the LGAS AVR and evaluate potential impact prosthesis-patient mismatch (PPM) in these patients.A cohort 664 undergoing for 1990 were followed-up prospectively annual clinical assessment echocardiography (total follow-up 3447 patient-years; mean 5.2+/-3.3 years). defined as an area <1.2 cm2, a transvalvular pressure gradient <40 mm Hg,...
Background— Heart failure with reduced ejection fraction and obstructive sleep apnea (OSA), 2 states of increased metabolic demand sympathetic nervous system activation, often coexist. Continuous positive airway pressure (CPAP), which alleviates OSA, can improve ventricular function. It is unknown whether this due to altered oxidative metabolism or presynaptic nerve We hypothesized that short-term (6–8 weeks) CPAP in patients OSA heart would myocardial function energetics. Methods Results—...
Background— The objective of this study was to examine the impact left ventricular (LV) global longitudinal strain (GLS) measured at rest and dobutamine stress echocardiography on outcome patients with low LV ejection fraction low-gradient aortic stenosis. Methods Results— Among 202 (≤40%), stenosis (mean transvalvular gradient <40 mm Hg indexed valve area ≤0.6 cm 2 /m ) prospectively enrolled in multicenter True or Pseudo-Severe Aortic Stenosis study, 126 resting GLS 73 available were...
To investigate the impact of blood pressure (BP) on Doppler echocardiographic (Doppler-echo) evaluation severity aortic stenosis (AS).Handgrip exercise or phenylephrine infusion was used to increase BP in 22 patients with AS. Indices AS (mean gradient (DeltaP(mean)), valve area (AVA), resistance, percentage left ventricular stroke work loss (% LVSW loss) and energy coefficient (ELCo)) were measured at baseline, peak intervention recovery.From baseline intervention, mean (SD) increased (99...