Simon Malenfant, PhD - Université Laval

Simon Malenfant

PhD

Université Laval

Québec, Qc | Canada

Main Specialties: Internal Medicine, Physical Medicine & Rehabilitation, Pulmonary Disease & Critical Care Medicine

Additional Specialties: Pulmonary vascular disease

ORCID logohttps://orcid.org/0000-0002-3911-3702


Top Author

Simon Malenfant, PhD - Université Laval

Simon Malenfant

PhD

Introduction

After completing his first post-doctoral training year with our group, Dr. Malenfant left the UVRL in August of 2017 to accept a position as a medical student at Université Laval in Quebec City, Canada.

Primary Affiliation: Université Laval - Québec, Qc , Canada

Specialties:

Additional Specialties:

Research Interests:


View Simon Malenfant’s Resume / CV

Education

Oct 2016 - Aug 2017
University of Utah
Fellowship
Internal Medicine
Sep 2016
Université Laval
PhD
Kinesiology
Sep 2007 - Apr 2010
Université Laval
BSc
Kinesiology

Publications

15Publications

324Reads

58Profile Views

282PubMed Central Citations

Dynamic cerebral autoregulation is attenuated in young fit women.

Physiol Rep 2019 Jan;7(2):e13984

Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada.

Young women exhibit higher prevalence of orthostatic hypotension with presyncopal symptoms compared to men. These symptoms could be influenced by an attenuated ability of the cerebrovasculature to respond to rapid blood pressure (BP) changes [dynamic cerebral autoregulation (dCA)]. The influence of sex on dCA remains unclear. dCA in 11 fit women (25 ± 2 years) and 11 age-matched men (24 ± 1 years) was compared using a multimodal approach including a sit-to-stand (STS) and forced BP oscillations (repeated squat-stand performed at 0.05 and 0.10 Hz). Prevalence of initial orthostatic hypotension (IOH; decrease in systolic ? 40 mmHg and/or diastolic BP ? 20 mmHg) during the first 15 sec of STS was determined as a functional outcome. In women, the decrease in mean middle cerebral artery blood velocity (MCAv ) following the STS was greater (-20 ± 8 vs. -11 ± 7 cm sec ; P = 0.018) and the onset of the regulatory change (time lapse between the beginning of the STS and the increase in the conductance index (MCAv /mean arterial pressure) was delayed (P = 0.007). Transfer function analysis gain during 0.05 Hz squat-stand was ~48% higher in women (6.4 ± 1.3 vs. 3.8 ± 2.3 cm sec mmHg ; P = 0.017). Prevalence of IOH was comparable between groups (women: 4/9 vs. men: 5/9, P = 0.637). These results indicate the cerebrovasculature of fit women has an attenuated ability to react to rapid changes in BP in the face of preserved orthostasis, which could be related to higher resting cerebral blood flow allowing women to better face transient hypotension.

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http://dx.doi.org/10.14814/phy2.13984DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6335382PMC
January 2019
1 Read

Diminished dynamic cerebral autoregulatory capacity with forced oscillations in mean arterial pressure with elevated cardiorespiratory fitness.

Physiol Rep 2017 Nov;5(21)

Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada

The effect that cardiorespiratory fitness has on the dynamic cerebral autoregulatory capacity during changes in mean arterial pressure (MAP) remains equivocal. Using a multiple-metrics approach, challenging MAP across the spectrum of physiological extremes (i.e., spontaneous through forced MAP oscillations), we characterized dynamic cerebral autoregulatory capacity in 19 male endurance athletes and eight controls via three methods: (1) onset of regulation (i.e., time delay before an increase in middle cerebral artery (MCA) conductance [MCA blood velocity (MCAv)/MAP] and rate of regulation, after transient hypotension induced by sit-to-stand, and transfer function analysis (TFA) of MAP and MCAv responses during (2) spontaneous and (3) forced oscillations (5-min of squat-stand maneuvers performed at 0.05 and 0.10 Hz). Reductions in MAP and mean MCAv (MCAV) during initial orthostatic stress (0-30 sec after sit-to-stand) and the prevalence of orthostatic hypotension were also determined. Onset of regulation was delayed after sit-to-stand in athletes (3.1 ± 1.7 vs. 1.5 ± 1.0 sec;  = 0.03), but rate of regulation was not different between groups (0.24 ± 0.05 vs. 0.21 ± 0.09 sec;  = 0.82). While both groups had comparable TFA metrics during spontaneous oscillations, athletes had higher TFA gain during 0.10 Hz squat-stand versus recreational controls ( = 0.01). Reductions in MAP ( = 0.15) and MCAV ( = 0.11) during orthostatic stress and the prevalence of initial orthostatic hypotension ( = 0.65) were comparable between groups. These results indicate an intact ability of the cerebral vasculature to react to spontaneous oscillations but an attenuated capability to counter rapid and large changes in MAP in individuals with elevated cardiorespiratory fitness.

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http://dx.doi.org/10.14814/phy2.13486DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5688778PMC
November 2017
13 Reads
5 Citations

Compromised Cerebrovascular Regulation and Cerebral Oxygenation in Pulmonary Arterial Hypertension.

J Am Heart Assoc 2017 Oct 12;6(10). Epub 2017 Oct 12.

Pulmonary Hypertension and Vascular Biology Research Group, Université Laval, Quebec City, Canada

Background: Functional cerebrovascular regulatory mechanisms are important for maintaining constant cerebral blood flow and oxygen supply in heathy individuals and are altered in heart failure. We aim to examine whether pulmonary arterial hypertension (PAH) is associated with abnormal cerebrovascular regulation and lower cerebral oxygenation and their physiological and clinical consequences.

Methods And Results: Resting mean flow velocity in the middle cerebral artery mean flow velocity in the middle cerebral artery (MCAv); transcranial Doppler), cerebral pressure-flow relationship (assessed at rest and during squat-stand maneuvers; analyzed using transfer function analysis), cerebrovascular reactivity to CO, and central chemoreflex were assessed in 11 patients with PAH and 11 matched healthy controls. Both groups also completed an incremental ramp exercise protocol until exhaustion, during which MCAv, mean arterial pressure, cardiac output (photoplethysmography), end-tidal partial pressure of CO, and cerebral oxygenation (near-infrared spectroscopy) were measured. Patients were characterized by a significant decrease in resting MCAv (<0.01) and higher transfer function gain at rest and during squat-stand maneuvers (both <0.05). Cerebrovascular reactivity to CO was reduced (=0.03), whereas central chemoreceptor sensitivity was increased in PAH (<0.01), the latter correlating with increased resting ventilation (=0.47; <0.05) and the exercise ventilation/CO production slope (V?E/V?CO2 slope; =0.62; <0.05) during exercise for patients. Exercise-induced increases in MCAv were limited in PAH (<0.05). Reduced MCAv contributed to impaired cerebral oxygen delivery and oxygenation (both <0.05), the latter correlating with exercise capacity in patients with PAH (=0.52; =0.01).

Conclusions: These findings provide comprehensive evidence for physiologically and clinically relevant impairments in cerebral hemodynamic regulation and oxygenation in PAH.

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http://dx.doi.org/10.1161/JAHA.117.006126DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5721836PMC
October 2017
209 Reads
4 Citations
4.450 Impact Factor

Evidence for hysteresis in the cerebral pressure-flow relationship in healthy men.

Am J Physiol Heart Circ Physiol 2017 Apr 27;312(4):H701-H704. Epub 2017 Jan 27.

Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada.

The cerebrovasculature is more efficient at compensating for pharmacologically induced transient hypertension versus transient hypotension. Whether this phenomenon exists during nonpharmacologically induced hypertension and hypotension is currently unknown. We compared the percent change in mean velocity in the middle cerebral artery (MCAvmean) per percent change in mean arterial pressure (MAP) (%?MCAVmean/%?MAP) during transient hypertension and hypotension induced during squat-stand maneuvers performed at 0.05 Hz (20-s cycles) and 0.10 Hz (10-s cycles) in 58 male volunteers. %?MCAvmean/%?MAP was attenuated by 25% ( = 0.03, 0.05 Hz) and 47% ( < 0.0001, 0.10 Hz) during transient hypertension versus hypotension. Thus, these findings indicate that the brain in healthy men is better adapted to compensate for physiologically relevant transient hypertension than hypotension. The novel finding of this study is that the change in middle cerebral artery mean flow velocity is attenuated during hypertension compared with hypotension physiologically induced by oscillations in blood pressure in men. These results support that the human brain is more effective at compensating for transient hypertension than hypotension.

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http://dx.doi.org/10.1152/ajpheart.00790.2016DOI Listing
April 2017
3 Reads
15 Citations
3.838 Impact Factor

β-blockers in pulmonary arterial hypertension: generation might matter.

Eur Respir J 2016 Feb;47(2):682-4

Pulmonary Hypertension and Vascular Biology Research Group, Centre de recherche de l'Institut Universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC, Canada UMR_S 999, Univ. Paris-Sud; INSERM; Laboratoire d'Excellence (LabEx) en Recherche sur le Médicament et l'Innovation Thérapeutique (LERMIT), Centre Chirurgical Marie Lannelongue, Le Plessis Robinson, France

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http://dx.doi.org/10.1183/13993003.01244-2015DOI Listing
February 2016
13 Reads
1 Citation
12.242 Impact Factor

Impaired Skeletal Muscle Oxygenation and Exercise Tolerance in Pulmonary Hypertension.

Med Sci Sports Exerc 2015 Nov;47(11):2273-82

1Pulmonary Hypertension Research Group, Québec Heart and Lungs Institute Research Center, Laval University, Québec City, Québec, CANADA; and 2Québec Heart and Lungs Institute Research Center, Laval University, Québec City, Québec, CANADA.

Background: Limb muscle dysfunction is documented in pulmonary arterial hypertension (PAH), but little is known regarding muscle oxygen (O2) supply and its possible effects on exercise tolerance in PAH.

Methods: Ten patients with PAH and 10 matched controls underwent progressive maximal cardiopulmonary exercise test, voluntary and nonvolitional dominant quadriceps muscle strength measures, and nondominant quadriceps biopsy to assess maximal oxygen uptake, muscle function, and lower limb fiber type and capillarity, respectively. Both groups then performed normoxic and hyperoxic submaximal intensity exercise protocol at the same absolute workload during which muscle O2 supply was assessed by measuring changes in myoglobin-deoxyhemoglobin level (?[Mb-HHb]) and tissue oxygenation index in the dominant quadriceps using near-infrared spectroscopy. Changes in cardiac output, estimated systemic O2 delivery, and systemic O2 saturation were also assessed noninvasively throughout both submaximal exercises.

Results: Patients with PAH displayed lower maximal oxygen uptake (P < 0.01), skeletal muscle strength (P < 0.05), and capillarity (P = 0.01). Throughout the normoxic submaximal exercise protocol, ?[Mb-HHb] (P < 0.01) was higher whereas changes in tissue oxygenation index (P < 0.01) and systemic O2 saturation (P = 0.01) were lower in patients with PAH compared with those in controls. Conversely, changes in cardiac output and estimated systemic O2 delivery were similar between groups. Muscle oxygenation remained unchanged with O2 supplementation. Among variables known to influence tissue oxygenation, only quadriceps capillarity density correlated with ?[Mb-HHb] (r = -0.66, P < 0.01), which in turn correlated with maximal oxygen uptake (r = -0.64, P < 0.01), 6-min walked distance (r = -0.74, P = 0.01), and both voluntary (r = -0.46, P = 0.04) and nonvolitional (r = -0.50, P = 0.02) quadriceps strength.

Conclusions: Capillary rarefaction within the skeletal muscle influences exercise tolerance and quadriceps strength at least partly through impaired muscle oxygen supply in PAH.

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http://dx.doi.org/10.1249/MSS.0000000000000696DOI Listing
November 2015
5 Reads
17 Citations
4.291 Impact Factor

Skeletal muscle proteomic signature and metabolic impairment in pulmonary hypertension.

J Mol Med (Berl) 2015 May 30;93(5):573-84. Epub 2014 Dec 30.

Pulmonary Hypertension Research Group, Centre de Recherche de l'Institut de Cardiologie et de Pneumologie de Québec, Service de Pneumologie, 2725 Chemin Sainte-Foy, Québec City, QC, G1V 4G5, Canada.

Unlabelled: Exercise limitation comes from a close interaction between cardiovascular and skeletal muscle impairments. To better understand the implication of possible peripheral oxidative metabolism dysfunction, we studied the proteomic signature of skeletal muscle in pulmonary arterial hypertension (PAH). Eight idiopathic PAH patients and eight matched healthy sedentary subjects were evaluated for exercise capacity, skeletal muscle proteomic profile, metabolism, and mitochondrial function. Skeletal muscle proteins were extracted, and fractioned peptides were tagged using an iTRAQ protocol. Proteomic analyses have documented a total of 9 downregulated proteins in PAH skeletal muscles and 10 upregulated proteins compared to healthy subjects. Most of the downregulated proteins were related to mitochondrial structure and function. Focusing on skeletal muscle metabolism and mitochondrial health, PAH patients presented a decreased expression of oxidative enzymes (pyruvate dehydrogenase, p?
Key Message: • Proteomic and metabolic analysis show abnormal oxidative metabolism in PAH skeletal muscle. • EM of PAH patients reveals abnormal mitochondrial structure and distribution. • Abnormal mitochondrial health and function contribute to exercise impairments of PAH. • PAH may be considered a vascular affliction of heart and lungs with major impact on peripheral muscles.

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http://dx.doi.org/10.1007/s00109-014-1244-0DOI Listing
May 2015
6 Reads
21 Citations
5.107 Impact Factor

Alternatives to the six-minute walk test in pulmonary arterial hypertension.

PLoS One 2014 11;9(8):e103626. Epub 2014 Aug 11.

Pulmonary Hypertension Research Group, Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec (Québec), Canada.

Introduction: The physiological response during the endurance shuttle walk test (ESWT), the cycle endurance test (CET) and the incremental shuttle walk test (ISWT) remains unknown in PAH. We tested the hypothesis that endurance tests induce a near-maximal physiological demand comparable to incremental tests. We also hypothesized that differences in respiratory response during exercise would be related to the characteristics of the exercise tests.

Methods: Within two weeks, twenty-one PAH patients (mean age: 54(15) years; mean pulmonary arterial pressure: 42(12) mmHg) completed two cycling exercise tests (incremental cardiopulmonary cycling exercise test (CPET) and CET) and three field tests (ISWT, ESWT and six-minute walk test (6MWT)). Physiological parameters were continuously monitored using the same portable telemetric device.

Results: Peak oxygen consumption (VO(2peak)) was similar amongst the five exercise tests (p = 0.90 by ANOVA). Walking distance correlated markedly with the VO(2peak) reached during field tests, especially when weight was taken into account. At 100% exercise, most physiological parameters were similar between incremental and endurance tests. However, the trends overtime differed. In the incremental tests, slopes for these parameters rose steadily over the entire duration of the tests, whereas in the endurance tests, slopes rose sharply from baseline to 25% of maximum exercise at which point they appeared far less steep until test end. Moreover, cycling exercise tests induced higher respiratory exchange ratio, ventilatory demand and enhanced leg fatigue measured subjectively and objectively.

Conclusion: Endurance tests induce a maximal physiological demand in PAH. Differences in peak respiratory response during exercise are related to the modality (cycling vs. walking) rather than the progression (endurance vs. incremental) of the exercise tests.

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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0103626PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4128819PMC
April 2015
7 Reads
11 Citations
3.234 Impact Factor

Impaired angiogenesis and peripheral muscle microcirculation loss contribute to exercise intolerance in pulmonary arterial hypertension.

Am J Respir Crit Care Med 2014 Aug;190(3):318-28

Pulmonary Hypertension Research Group, Quebec Heart and Lung Institute Research Center, Laval University, Quebec City, Canada.

Rationale: Pulmonary arterial hypertension (PAH) is characterized by significant exercise intolerance, which is multifactorial and involves skeletal muscle alterations. There is growing evidence that microRNAs (miRs) are involved in PAH pathogenesis.

Objectives: We hypothesized that miR-126, an endothelial-specific, proangiogenic miR, is down-regulated in the peripheral muscles of patients with PAH, which would account for skeletal muscle microcirculation loss and exercise intolerance.

Measurements And Main Results: Patients with PAH displayed decreases in exercise capacity ([Formula: see text]o2max) and microcirculation loss on quadriceps muscle biopsy (in CD31(+) immunofluorescence experiments) compared to control subjects. Exercise capacity correlated with muscle capillarity (r = 0.84, P < 0.01). At the cellular level, vascular endothelial growth factor (VEGF) and VEGF receptor 2 expression were similar in both groups. Conversely, PAH was associated with a 60% decrease in miR-126 expression in a quantitative reverse transcriptase polymerase chain reaction experiment (P < 0.01), resulting in up-regulation of its targeted protein, Sprouty-related, EVH1 domain-containing protein 1 (SPRED-1), and a marked decrease in the downstream effectors of the VEGF pathway, p-Raf/Raf and p-ERK/ERK, as determined by immunoblot analysis. Using freshly isolated CD31(+) cells from human quadriceps biopsies, we found that the down-regulation of miR-126 in PAH triggered the activation of SPRED-1, impairing the angiogenic response (Matrigel assay). These abnormalities were reversed by treating the PAH cells with miR-126 mimic, whereas inhibition of miR-126 (antagomir) in healthy CD31(+) cells fully mimicked the PAH phenotype. Finally, miR-126 down-regulation in skeletal muscle of healthy rats decreased muscle capillarity in immunofluorescence assays (P < 0.05) and exercise tolerance in treadmill tests (P < 0.05), whereas miR-126 up-regulation increased them in monocrotaline PAH rats.

Conclusions: We demonstrate for the first time that exercise intolerance in PAH is associated with skeletal muscle microcirculation loss and impaired angiogenesis secondary to miR-126 down-regulation.

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http://dx.doi.org/10.1164/rccm.201402-0383OCDOI Listing
August 2014
32 Reads
64 Citations
15.240 Impact Factor

Repeatability and responsiveness of exercise tests in pulmonary arterial hypertension.

Eur Respir J 2013 Aug 25;42(2):425-34. Epub 2012 Oct 25.

Centre de recherche de l'Institut Universitaire de cardiologie et de pneumologie de Québec, Université Laval, Québec, QC, Canada.

Exercise tolerance in pulmonary arterial hypertension (PAH) is most commonly assessed by the 6-min walk test (6MWT). Whether endurance exercise tests are more responsive than the 6MWT remains unknown. 20 stable PAH patients (mean±sd age 53±15 years and mean pulmonary arterial pressure 44±16 mmHg) already on PAH monotherapy completed the 6MWT, the endurance shuttle walk test (ESWT) and the cycle endurance test (CET) before and after the addition of sildenafil citrate 20 mg three times daily or placebo for 28 days in a randomised double-blind crossover setting. Pre- or post-placebo tests were used to assess repeatability of each exercise test, whereas pre- or post-sildenafil citrate tests were used to assess their responsiveness. Sildenafil citrate led to placebo-corrected changes in exercise capacity of 18±25 m (p = 0.02), 58±235 s (p = 0.58) and 29±77 s (p = 0.09) for the 6MWT, the ESWT and the CET, respectively. The 6MWT was associated with a lower coefficient of variation between repeated measures (3% versus 18% versus 13%), resulting in a higher standardised response mean compared with endurance tests (0.72, 0.25 and 0.38 for the 6MWT, the ESWT and the CET, respectively). The 6MWT had the best ability to capture changes in exercise capacity when sildenafil citrate was combined with patients' baseline monotherapy, supporting its use as an outcome measure in PAH.

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http://dx.doi.org/10.1183/09031936.00107012DOI Listing
August 2013
4 Reads
11 Citations
12.242 Impact Factor

Signal transduction in the development of pulmonary arterial hypertension.

Pulm Circ 2013 Apr;3(2):278-93

Pulmonary Hypertension Research Group of the Institut universitaire de cardiologie et de pneumologie de Quebec Research Center, Laval University, Quebec City, Canada.

Pulmonary arterial hypertension (PAH) is a unique disease. Properly speaking, it is not a disease of the lung. It can be seen more as a microvascular disease occurring mainly in the lungs and affecting the heart. At the cellular level, the PAH paradigm is characterized by inflammation, vascular tone imbalance, pulmonary arterial smooth muscle cell proliferation and resistance to apoptosis and the presence of in situ thrombosis. At a clinical level, the aforementioned abnormal vascular properties alter physically the pulmonary circulation and ventilation, which greatly influence the right ventricle function as it highly correlates with disease severity. Consequently, right heart failure remains the principal cause of death within this cohort of patients. While current treatment modestly improve patients' conditions, none of them are curative and, as of today, new therapies are lacking. However, the future holds potential new therapies that might have positive influence on the quality of life of the patient. This article will first review the clinical presentation of the disease and the different molecular pathways implicated in the pathobiology of PAH. The second part will review tomorrow's future putative therapies for PAH.

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http://dx.doi.org/10.4103/2045-8932.114752DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3757823PMC
April 2013
3 Reads
63 Citations
2.900 Impact Factor

The emergence of new therapeutic targets in pulmonary arterial hypertension: from now to the near future.

Expert Rev Respir Med 2013 Feb;7(1):43-55

Pulmonary Hypertension Research Group, Centre de recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, 2725 Chemin Ste-Foy, Québec G1V 4G5, Canada.

Pulmonary arterial hypertension (PAH) is a vascular remodeling disease that pathologically increases pulmonary vascular resistance. Ultimately, this leads to right ventricular failure and premature death. Current therapeutic strategies are mainly designed to induce relaxation of the pulmonary arteries, but are not directly aimed to improve vascular remodeling that characterize PAH. Although these treatments modestly improve patient symptoms, pulmonary hemodynamics and survival, none of them are curative and approximately 15% of patients die within 1 year of medical follow-up despite treatment. Within the last 5 years, tremendous advances in our understanding of the PAH pathophysiology have arisen. These advances have a high potential for the development of better patient care by providing novel therapeutic targets. The goal of this report is to review the current PAH treatments, as well as novel therapies that will pave the future in this devastating disease.

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http://dx.doi.org/10.1586/ers.12.83DOI Listing
February 2013
5 Reads
16 Citations
2.607 Impact Factor

The incidence of behaviours associated with body checking among youth ice hockey players.

J Sci Med Sport 2012 Sep 10;15(5):463-7. Epub 2012 Apr 10.

Laval University, Department of Physical Education, Faculty of Education, Québec, Canada.

Objectives: To determine if a difference exists between the incidence and intensity of the physical contacts of Pee Wee (aged 11-12 years) ice hockey players according to whether the players participate in a league in which body checking is permitted (Calgary, Canada) compared to a league in which body checking is not permitted (Québec City, Canada).

Design: Cohort study conducted in Québec City and Calgary during the 2007-2008 Pee Wee ice hockey season.

Methods: Ten games were randomly selected for each city (n=20) and analysed. Games were videotaped and subsequently analysed with a validated observation system allowing quantification of the intensity of the various physical contacts. Incidence rate ratios (RR) based on multivariate Poisson regression were used to compare the physical contacts between provinces. All analyses were controlling for game period, score difference, and zone on the playing surface.

Results: A total of 2418 physical contacts with the trunk and 757 other physical contacts were observed. Very light intensity trunk physical contacts were more frequent in Québec City (adjusted incidence RR [ARR]: 0.68; 95% CI: 0.48-0.97). Very high intensity trunk physical contacts were more frequent in Calgary (ARR: 12.72; 95% CI: 4.48-36.14). Hooking (ARR: 0.89; 95% CI: 0.84-0.95) and slashing (ARR: 0.91; 95% CI: 0.85-0.97) were more frequent in Québec City.

Conclusions: Results suggest that players' behaviours are different in leagues where body checking is permitted compared to leagues where it is not permitted. Policy allowing body checking in Pee Wee ice hockey increases the frequency and intensity of physical contacts.

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http://dx.doi.org/10.1016/j.jsams.2012.03.003DOI Listing
September 2012
10 Reads
11 Citations
3.875 Impact Factor

Assessment of daily life physical activities in pulmonary arterial hypertension.

PLoS One 2011 16;6(11):e27993. Epub 2011 Nov 16.

Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Canada.

Background: In pulmonary arterial hypertension (PAH), the six-minute walk test (6MWT) is believed to be representative of patient's daily life physical activities (DL(PA)). Whether DL(PA) are decreased in PAH and whether the 6MWT is representative of patient's DL(PA) remain unknown.

Methods: 15 patients with idiopathic PAH (IPAH) and 10 patients with PAH associated with limited systemic sclerosis (PAH-SSc) were matched with 15 healthy control subjects and 10 patients with limited systemic sclerosis without PAH. Each subject completed a 6MWT. The mean number of daily steps and the mean energy expenditure and duration of physical activities >3 METs were assessed with a physical activity monitor for seven consecutive days and used as markers of DL(PA).

Results: The mean number of daily steps and the mean daily energy expenditure and duration of physical activities >3 METs were all reduced in PAH patients compared to their controls (all p<0.05). The mean number of daily steps correlated with the 6MWT distance for both IPAH and PAH-SSc patients (r?=?0.76, p<0.01 and r?=?0.85, p<0.01), respectively.

Conclusion: DL(PA) are decreased in PAH and correlate with the 6MWT distance. Functional exercise capacity may thus be a useful surrogate of DL(PA) in PAH.

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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0027993PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3218075PMC
March 2012
4 Reads
42 Citations
3.234 Impact Factor

Top co-authors

Steeve Provencher
Steeve Provencher

Université Laval

9
Sebastien Bonnet
Sebastien Bonnet

University of Alberta

8
Vincent Mainguy
Vincent Mainguy

Université Laval

5
Patrice Brassard
Patrice Brassard

Université Laval

5
Francois Maltais
Francois Maltais

McGill University Health Centre

5
Didier Saey
Didier Saey

Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec

4
Francois Potus
Francois Potus

and Cardiovascular Research Laboratories (M.E.)

4
Myriam Paquette
Myriam Paquette

Université Laval

4
Anne-Sophie Neyron
Anne-Sophie Neyron

Université Laval

3