ORCID Profile
0000-0002-2013-639X
Current Organisation
KU Leuven
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Publisher: Elsevier BV
Date: 12-2015
Publisher: Oxford University Press (OUP)
Date: 03-10-2019
DOI: 10.1093/EHJCI/JEZ228
Abstract: Athletes with right ventricular (RV) arrhythmias, even in the absence of desmosomal mutations, may have subtle RV abnormalities which can be unmasked by deformation imaging. As exercise places a disproportionate stress on the right ventricle, evaluation of cardiac function and deformation during exercise might improve diagnostic performance. We performed bicycle stress echocardiography in 17 apparently healthy endurance athletes (EAs), 12 non-athletic controls (NAs), and 17 athletes with RV arrhythmias without desmosomal mutations (EI-ARVCs) and compared biventricular function at rest and during low (25% of upright peak power) and moderate intensity (60%). At rest, we observed no differences in left ventricular (LV) or RV function between groups. During exercise, however, the increase in RV fractional area change (RVFAC), RV free wall strain (RVFWSL), and strain rate (RVFWSRL) were significantly attenuated in EI-ARVCs as compared to EAs and NAs. At moderate exercise intensity, EI-ARVCs had a lower RVFAC, RVFWSL, and RVFWSRL (all P 0.01) compared to the control groups. Exercise-related increases in LV ejection fraction, strain, and strain rate were also attenuated in EI-ARVCs (P 0.05 for interaction). Exercise but not resting parameters identified EI-ARVCs and RVFWSRL with a cut-off value of −2.35 at moderate exercise intensity had the greatest accuracy to detect EI-ARVCs (area under the curve 0.95). Exercise deformation imaging holds promise as a non-invasive diagnostic tool to identify intrinsic RV dysfunction concealed at rest. Strain rate appears to be the most accurate parameter and should be incorporated in future, prospective studies to identify subclinical disease in an early stage.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2014
Publisher: Oxford University Press (OUP)
Date: 07-03-2022
Abstract: Cardiac output limitation is a fundamental feature of heart failure with preserved ejection fraction (HFpEF) but the relative contribution of its determinants in symptomatic vs. asymptomatic stages are not well characterized. We aimed to gain insight into disease mechanisms by performing comprehensive comparative non-invasive exercise imaging in patients across the disease spectrum. We performed bicycle stress echocardiography in 10 healthy controls, 13 patients with hypertensive left ventricular (LV) concentric remodelling and asymptomatic diastolic dysfunction (HTDD), 15 HFpEF patients, and 15 subjects with isolated right ventricular (RV) dysfunction secondary to chronic thromboembolic pulmonary hypertension (CTEPH). During exercise, ventricular performance differed across the groups (all P ≤ 0.01 for interaction). Notably in controls, LV and RV function significantly increased (all P & 0.05) while both LV systolic and diastolic reserve were significantly reduced in HFpEF patients. Likewise, RV systolic reserve was also impaired in HFpEF but not to the extent of CTEPH patients (P & 0.001 between groups). HTDD patients behaved as an intermediary group with borderline LV systolic and diastolic reserve and reduced RV systolic reserve. The increased pulmonary vascular (PV) load in HFpEF and CTEPH patients in combination with impaired RV reserve resulted in RV–pulmonary artery uncoupling during exercise. The multifaceted decline of cardiac and PV function accompanying disease progression in HFpEF is unmasked by exercise and already emerges in preclinical disease. The revelation of these subtle abnormalities during exercise illustrates the benefit of exercise imaging and creates new prospects for early diagnosis and management.
Publisher: BMJ
Date: 16-02-2015
DOI: 10.1136/HEARTJNL-2014-306851
Abstract: Symptoms in patients with chronic thromboembolic pulmonary hypertension (CTEPH) predominantly occur during exercise, while haemodynamic assessment is generally performed at rest. We hypothesised that exercise imaging of RV function would better explain exercise limitation and the acute effects of pulmonary vasodilator administration than resting measurements. Fourteen patients with CTEPH and seven healthy control subjects underwent cardiopulmonary testing to determine peak exercise oxygen consumption (VO2peak) and ventilatory equivalent for carbon dioxide (VE/VCO2) at the anaerobic threshold. Subsequently, cardiac MRI was performed at rest and during supine bicycle exercise with simultaneous invasive measurement of mean pulmonary arterial pressure (mPAP) before and after sildenafil. During exercise, patients with CTEPH had a greater increase in the ratio of mPAP relative to cardiac output (CO) than controls (6.7 (5.1-8.7) vs 0.94 (0.86-1.8) mm Hg/L/min p < 0.001). Stroke volume index (SVi) and RVEF increased during exercise in controls, but not in patients with CTEPH (interaction p < 0.001). Sildenafil decreased the mPAP/CO slope and increased SVi and RVEF in patients with CTEPH (p < 0.05) but not in controls. In patients with CTEPH, RVEF reserve correlated moderately with VO2peak (r = 0.60 p = 0.030) and VE/VCO2 (r = -0.67 p = 0.012). By contrast, neither VO2peak nor VE/VCO2 correlated with resting RVEF. Exercise measures of RV function explain much of the variance in the exercise capacity of patients with CTEPH while resting measures do not. Sildenafil increases SVi during exercise in patients with CTEPH, but not in healthy subjects.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2013
Publisher: BMJ
Date: 29-07-2015
DOI: 10.1136/BJSPORTS-2014-094546
Abstract: Subepicardial delayed gadolinium enhancement (DGE) patches without underlying cardiomyopathy is poorly understood. It is often reported as the result of prior silent myocarditis. Its prognostic relevance in asymptomatic athletes is unknown therefore, medical clearance for competitive sports participation is debated. This case series aims to relate this pattern of DGE in athletes to outcome. We report on seven young asymptomatic athletes with isolated subepicardial DGE detected during workup of abnormalities on their regular screening examination, that is, pathological T-wave inversions on ECG (n=4) or ventricular arrhythmias on exercise test (n=3). All underwent a comprehensive initial investigation in order to assess left ventricular (LV) function at rest and exercise (exercise cardiac MRI and/or exercise echocardiography) and occurrence of arrhythmias (exercise test, 24 h-ECG Holter, electrophysiological study). All underwent a careful follow-up with biannual evaluation. All athletes had extensive subepicardial DGE (12.0±4.8% of LV mass), predominantly in the lateral wall. Three athletes had non-sustained ventricular arrhythmias, whereas two of them had LV ejection fraction <50% at rest with no contractile reserve at exercise. During a follow-up of 3.0±1.5 years in the four remaining athletes, two had symptomatic ventricular tachycardia and one demonstrated progressive LV dysfunction. Hence, six of seven athletes had to be excluded from competitive sports participation. Isolated large areas of subepicardial DGE in an asymptomatic athlete are not benign and require a careful evaluation at exercise and a strict follow-up. These findings question whether extreme exercise during silent myocarditis may facilitate fibrosis generation and adverse remodelling.
Publisher: IOP Publishing
Date: 08-03-2019
Abstract: We propose and evaluate a method to estimate a respiratory signal from ungated cardiac magnetic resonance (CMR) images. Ungated CMR images were acquired in five subjects who performed exercise at different intensity levels under different physiological conditions while breathing freely. The respiratory motion was estimated by applying principal components analysis (PCA). A sign correction procedure was developed to correctly define inspiration and expiration, based on either tracking of the diaphragmatic motion or estimation of the lung volume or a combination of both. Evaluation was done using a plethysmograph signal as reference. There was a good correspondence between the plethysmograph and the estimated respiratory signals. Respiratory motion was effectively captured by one of the PCA components in 88% of the cases. Moreover, the proposed method successfully estimated the respiratory phase in 91% of the evaluated slices. The pipeline is robust, admitting a slight decline in performance with increased exercise intensity. Respiratory motion was accurately estimated by means of PCA and the application of a sign correction procedure. Our method showed promising results even for acquisitions during exercise where excessive body motion occurs. The proposed method provides a way to extract the respiratory signal from ungated CMR images, at rest as well as during exercise, in a fully unsupervised fashion, which may reduce the clinician's workload drastically.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2013
DOI: 10.1161/CIRCIMAGING.112.980037
Abstract: Accurate measures are critical when attempting to distinguish normal from pathological changes in cardiac function during exercise, yet imaging modalities have seldom been assessed against invasive exercise standards. We sought to validate a novel method of biventricular volume quantification by cardiac MRI (CMR) during maximal exercise. CMR was performed on 34 subjects during exercise and free-breathing with the use of an ungated real-time (RT-ungated) CMR sequence. ECG and respiratory movements were retrospectively synchronized, enabling compensation for cardiac cycle and respiratory phase. Feasibility of RT-ungated imaging was compared with standard exercise CMR imaging with ECG gating (gated) accuracy of RT-ungated CMR was assessed against an invasive standard (direct Fick) and reproducibility was determined after a second bout of maximal exercise. Ventricular volumes were analyzed more frequently during high-intensity exercise with RT-ungated compared with gated CMR (100% versus 47% P .0001) and with better interobserver variability for RT-ungated (coefficient of variation=1.9% and 2.0% for left and right ventricular stroke volumes, respectively) than gated (coefficient of variation=15.2% and 13.6% P .01). Cardiac output determined by RT-ungated CMR proved accurate against the direct Fick method with excellent agreement (intraclass correlation coefficient, R =0.96), which was highly reproducible during a second bout of maximal exercise ( R =0.98). When RT-ungated CMR is combined with post hoc analysis incorporating compensation for respiratory motion, highly reproducible and accurate biventricular volumes can be measured during maximal exercise.
Publisher: Oxford University Press (OUP)
Date: 02-06-2015
Abstract: Intense exercise places disproportionate strain on the right ventricle (RV) which may promote pro-arrhythmic remodelling in some athletes. RV exercise imaging may enable early identification of athletes at risk of arrhythmias. Exercise imaging was performed in 17 athletes with RV ventricular arrhythmias (EA-VAs), of which eight (47%) had an implantable cardiac defibrillator (ICD), 10 healthy endurance athletes (EAs), and seven non-athletes (NAs). Echocardiographic measures included the RV end-systolic pressure-area ratio (ESPAR), RV fractional area change (RVFAC), and systolic tricuspid annular velocity (RV S'). Cardiac magnetic resonance (CMR) measures combined with invasive measurements of pulmonary and systemic artery pressures provided left-ventricular (LV) and RV end-systolic pressure-volume ratios (SP/ESV), biventricular volumes, and ejection fraction (EF) at rest and during intense exercise. Resting measures of cardiac function were similar in all groups, as was LV function during exercise. In contrast, exercise-induced increases in RVFAC, RV S', and RVESPAR were attenuated in EA-VAs during exercise when compared with EAs and NAs (P < 0.0001 for interaction group × workload). During exercise-CMR, decreases in RVESV and augmentation of both RVEF and RV SP/ESV were significantly less in EA-VAs relative to EAs and NAs (P < 0.01 for the respective interactions). Receiver-operator characteristic curves demonstrated that RV exercise measures could accurately differentiate EA-VAs from subjects without arrhythmias [AUC for ΔRVESPAR = 0.96 (0.89-1.00), P < 0.0001]. Among athletes with normal cardiac function at rest, exercise testing reveals RV contractile dysfunction among athletes with RV arrhythmias. RV stress testing shows promise as a non-invasive means of risk-stratifying athletes.
Publisher: Oxford University Press (OUP)
Date: 26-05-2015
DOI: 10.1093/CVR/CVV165
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2014
DOI: 10.1161/CIRCIMAGING.113.001243
Abstract: Patients with Fontan circulation have reduced exercise capacity. The absence of a presystemic pump may limit flow through the pulmonary circulation, restricting ventricular filling and cardiac output. We evaluated exercise hemodynamics and the effect of sildenafil on exercise hemodynamics in Fontan patients. Ten Fontan patients (6 men, 20±4 years) underwent cardiac magnetic resonance imaging at rest and during supine bicycle exercise before and after sildenafil. Systemic ventricular volumes were obtained at rest and during low- (34±15 W), moderate- (69±29 W), and high-intensity (97±36 W) exercise using an ungated, free-breathing cardiac magnetic resonance sequence and analyzed correcting for cardiac phase and respiratory translation. Radial and pulmonary artery pressures and cGMP were measured. Before sildenafil, cardiac index increased throughout exercise (4.0±0.9, 5.9±1.1, 7.0±1.6, 7.4±1.7 L/(min·m 2 ) P .0001) with 106±49% increase in heart rate. Stroke volume index ( P =0.015) and end-diastolic volume index ( P =0.001) decreased during exercise. End-systolic volume index remained unchanged ( P =0.8). Total pulmonary resistance index ( P =0.005) increased, whereas systemic vascular resistance index decreased during exercise ( P .0001). Sildenafil increased cardiac index ( P .0001) and stroke volume index ( P =0.003), especially at high-intensity exercise (interaction P =0.004 and P =0.003, respectively). Systemic vascular resistance index was reduced ( P .0001–interaction P =0.1), whereas total pulmonary resistance index was reduced at rest and reduced further during exercise ( P =0.008–interaction P =0.029). cGMP remained unchanged before sildenafil ( P =0.9), whereas it increased significantly after sildenafil ( P =0.019). In Fontan patients, sildenafil improved cardiac index during exercise with a decrease in total pulmonary resistance index and an increase in stroke volume index. This implies that pulmonary vasculature represents a physiological limitation, which can be attenuated by sildenafil, the clinical significance of which warrants further study.
Publisher: American Physiological Society
Date: 15-03-2014
DOI: 10.1152/AJPHEART.00752.2013
Abstract: Breathing-induced changes in intrathoracic pressures influence left ventricular (LV) and right ventricular (RV) volumes, the exact nature and extent of which have not previously been evaluated in humans. We sought to examine this “respiratory pump” using novel real-time cardiac magnetic resonance (CMR) imaging. Eight healthy subjects underwent serial multislice real-time CMR during normal breathing, breath holding, and the Valsalva maneuver. Subsequently, a separate cohort of nine subjects underwent real-time CMR at rest and during incremental exercise. LV and RV end-diastolic volume (EDV) and end-systolic volume (ESV) and diastolic and systolic eccentricity indexes were determined at peak inspiration and expiration. During normal breathing, inspiration resulted in an increase in RV volumes [RVEDV: +18 ± 8%, RVESV: +14 ± 12%, and RV stroke volume (SV): +21 ± 10%, P 0.01] and an opposing decrease in LV volumes ( P 0.0001 for interaction). During end-inspiratory breath holding, RV SV decreased by 9 ± 10% ( P = 0.046), whereas LV SV did not change. During the Valsalva maneuver, volumes decreased in both ventricles (RVEDV: −29 ± 11%, RVESV: −16 ± 14%, RV SV: −36 ± 14%, LVEDV: −22 ± 17%, and LV SV: −25 ± 17%, P 0.01). The reciprocal effect of respiration on LV and RV volumes was maintained throughout exercise. The diastolic and systolic eccentricity indexes were greater during inspiration than during expiration, both at rest and during exercise ( P 0.0001 for both). In conclusion, ventricular volumes oscillate with respiratory phase such that RV and LV volumes are maximal at peak inspiration and expiration, respectively. Thus, interpretation of RV versus LV volumes requires careful definition of the exact respiratory time point for proper interpretation, both at rest and during exercise.
Publisher: Oxford University Press (OUP)
Date: 06-03-2023
DOI: 10.1093/EURHEARTJ/EHAD152
Abstract: The impact of long-term endurance sport participation (on top of a healthy lifestyle) on coronary atherosclerosis and acute cardiac events remains controversial. The Master@Heart study is a well-balanced prospective observational cohort study. Overall, 191 lifelong master endurance athletes, 191 late-onset athletes (endurance sports initiation after 30 years of age), and 176 healthy non-athletes, all male with a low cardiovascular risk profile, were included. Peak oxygen uptake quantified fitness. The primary endpoint was the prevalence of coronary plaques (calcified, mixed, and non-calcified) on computed tomography coronary angiography. Analyses were corrected for multiple cardiovascular risk factors. The median age was 55 (50–60) years in all groups. Lifelong and late-onset athletes had higher peak oxygen uptake than non-athletes [159 (143–177) vs. 155 (138–169) vs. 122 (108–138) % predicted]. Lifelong endurance sports was associated with having ≥1 coronary plaque [odds ratio (OR) 1.86, 95% confidence interval (CI) 1.17–2.94], ≥ 1 proximal plaque (OR 1.96, 95% CI 1.24–3.11), ≥ 1 calcified plaques (OR 1.58, 95% CI 1.01–2.49), ≥ 1 calcified proximal plaque (OR 2.07, 95% CI 1.28–3.35), ≥ 1 non-calcified plaque (OR 1.95, 95% CI 1.12–3.40), ≥ 1 non-calcified proximal plaque (OR 2.80, 95% CI 1.39–5.65), and ≥1 mixed plaque (OR 1.78, 95% CI 1.06–2.99) as compared to a healthy non-athletic lifestyle. Lifelong endurance sport participation is not associated with a more favourable coronary plaque composition compared to a healthy lifestyle. Lifelong endurance athletes had more coronary plaques, including more non-calcified plaques in proximal segments, than fit and healthy in iduals with a similarly low cardiovascular risk profile. Longitudinal research is needed to reconcile these findings with the risk of cardiovascular events at the higher end of the endurance exercise spectrum.
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.HEALUN.2016.06.018
Abstract: Non-invasive estimates have suggested that asymptomatic BMPR2 mutation carriers may have an abnormal pulmonary vascular response to exercise and hypoxia. However, this has not been assessed with "gold standard" invasive measures. Eight controls and 8 asymptomatic BMPR2 mutation carriers underwent cardiac magnetic resonance imaging with simultaneous invasive pressure recording during bicycle exercise in normoxia, hypoxia and after sildenafil administration. Abnormal pulmonary vascular reserve was defined as an increase in mean pulmonary artery pressure relative to cardiac output (P/Q slope) >3 mm Hg/liter/min. During normoxic exercise, BMPR2 mutation carriers had a similar P/Q slope when compared with healthy subjects. Only 1 of 8 BMPR2 mutation carriers had a P/Q slope >3 mm Hg/liter/min. During exercise in hypoxia, 3 of 8 BMPR2 mutation carriers had P/Q slopes >3 mm Hg/liter/min compared with none of the controls. Sildenafil decreased the P/Q slope both in controls and BMPR2 mutation carriers. The exercise-induced increase in right ventricular ejection fraction was similar between groups. None of the BMPR2 mutation carriers developed pulmonary arterial hypertension within 2 (range 1.3 to 2.8) years. The presence of a BMPR2 mutation, per se, is not associated with an abnormal pulmonary vascular and right ventricular functional response to exercise in asymptomatic in iduals. Longer follow-up will be required to determine whether a P/Q slope of >3 mm Hg/liter/min during exercise in normoxia or hypoxia is a sign of pre-clinical disease expression.
No related grants have been discovered for Piet Claus.