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Background: Pulmonary insufficiency (PI) and right ventricular (RV) dysfunction are long-term complications in patients with repaired tetralogy of Fallot (rTOF). The aim of this study was to investigate RV contractile reserve and changes in PI that occur during exercise in patients with rTOF and the associations of these changes with exercise performance using stress echocardiography.
Methods: Subjects with rTOF (n = 32) and healthy control subjects (n = 10) were prospectively enrolled and underwent rest and peak exercise echocardiography during standard cardiopulmonary exercise test protocol on a cycle ergometer or treadmill. RV contractile reserve was defined as the change in RV global longitudinal strain from rest to peak exercise. PI was assessed with the diastolic-to-systolic time-velocity integral ratio and diastolic/systolic velocity ratio from pulmonary artery Doppler interrogation. Exercise measures included heart rate reserve, percentage predicted maximum oxygen consumption, percentage predicted maximum work, and oxygen pulse.
Results: RV contractile reserve was impaired in patients with rTOF compared with control subjects, with a significant drop in the absolute value of RV global longitudinal strain from 17% (range, 8%-27%) at rest to 13% (range, 5%-28%) at peak exercise. Similarly, PI decreased at peak exercise, with decreases in diastolic-to-systolic time-velocity integral and diastolic/systolic velocity ratios. Reduction in PI was directly associated with percentage predicted maximum oxygen consumption, percentage predicted maximum work, and greater oxygen pulse. Heart rate reserve was directly associated with percentage predicted maximum oxygen consumption and percentage predicted maximum work. RV contractile reserve was not associated with any exercise parameters.
Conclusions: Patients with rTOF have an abnormal myocardial response to exercise with impaired RV contractile reserve compared with control subjects. Heart rate reserve and reduction in PI at peak exercise are associated with better exercise performance and appear to be significant contributors to exercise performance in rTOF. Measures to improve chronotropic health in rTOF should be explored.
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http://dx.doi.org/10.1016/j.echo.2018.08.008 | DOI Listing |
J Am Soc Echocardiogr
September 2025
From the Department of Cardiovascular Medicine, Mayo Clinic Rochester, MN 55905.
Background: Pulmonary hypertension is associated with cardiovascular events, but when assessed at rest, it has limited sensitivity. Pulmonary vascular reserve can be assessed noninvasively using exercise echocardiography, but this has not been studied in adults with coarctation of aorta (COA). We hypothesized that adults with COA had worse pulmonary vascular reserve compared to controls, and that impaired pulmonary vascular reserve was associated with clinical indices of disease severity independent right ventricular (RV) indices at rest.
View Article and Find Full Text PDFJ Mol Cell Cardiol Plus
September 2025
Department of Computer Science, University of Oxford, Oxford, United Kingdom.
Background: Women are under-represented in cardiovascular research, leading to poorer outcomes. Investigating sex-differences in electromechanical function is essential for improving therapy evaluation. This study presents sex-specific human cellular and biventricular electromechanical models for mechanistic investigation of sex-differences in therapeutic response.
View Article and Find Full Text PDFJ Gen Physiol
November 2025
Department of Molecular Physiology and Biophysics, Larner College of Medicine, University of Vermont, Burlington, VT, USA.
Cardiac contractility is driven by shortening of ∼2-μm-long, macromolecular assemblies known as sarcomeres. During contraction, the motor protein myosin binds to, and exerts force upon actin filaments, utilizing energy from the hydrolysis of ATP. When not actively contracting, myosin partition into two subpopulations, distinguished by their basal rates of ATP hydrolysis, known as the "Disordered Relaxed" (DRX) and "Super Relaxed" (SRX) states.
View Article and Find Full Text PDFSci Rep
August 2025
Makerere University Lung Institute, PO Box 26343, Kampala, Uganda.
Mechanisms by which prior tuberculosis (TB) increases long-term risk for cancer, cardiovascular, and neurological disorders remain unclear, particularly in people with HIV (PWH). This study investigated DNA methylation (DNAm) patterns and associated pathways in PWH with and without prior TB infection. DNAm was analyzed in blood samples from 30 PWH (10 with prior latent TB infection [LTBI], 10 with previous successfully treated active TB, and 10 with no TB) using the Illumina MethylationEPIC BeadChip covering over 850,000 CpG sites.
View Article and Find Full Text PDFEur J Heart Fail
August 2025
Department of Internal Medicine, Justus-Liebig-University Giessen, Universities of Giessen and Marburg Lung Center (UGMLC), Institute for Lung Health (ILH), Cardio-Pulmonary Institute (CPI), Member of the German Center for Lung Research (DZL), Giessen, Germany.
Aims: The haemodynamic response to exercise is prognostic in pulmonary hypertension (PH). However, little is known about right ventricular (RV) adaptation in this context. We analysed the patterns and prognostic relevance of RV adaptation to exercise in PH.
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