BACKGROUND:The first (VT1) and second (VT2) ventilatory thresholds are landmarks to tailor exercise rehabilitation in coronary artery disease (CAD) or chronic heart failure (CHF). Methods allowing VT1 and VT2 determination based on heart rate variability (HRV) have been proposed but not yet evaluated in these patients.DESIGN:To determine the heart rate (HR) associated with VT1 and VT2 by three methods of HRV analyses.METHODS:Fourteen CHF and 24 CAD patients performed an exercise test on a cycle ergometer (10 -W every minute until exhaustion). VT1 and VT2 were determined with the 'respiratory equivalent' method. HR at VT1 was determined with the standard deviation (SD) of R⊟R intervals (VT(SD)) and of the instantaneous beat-to-beat variability of the Poincaré plot method (VT(Poincaré)). HR at VT1 and VT2 was determined through a time-varying HRV analysis method (VT(TV1) and VT(TV2), respectively).RESULTS:HR at VT(SD) was significantly higher than HR at VT1. No significant differences were observed between HR at VT(Poincaré), VT(TV1), and at VT1, nor between HR at VT(TV2) and VT2. HR at VT(SD), VT(Poincaré), and VT1 were significantly correlated, but with a low r (2) value and a large mean HR difference. With the time-varying method, the mean HR difference was lower than 5% and the correlation coefficients were higher (especially for VT(TV2)).CONCLUSIONS:SD and Poincaré plot methods lead to substantial inaccuracy in HR estimates. The time-varying HRV analysis led to strong correlation coefficients and low limits of agreement. Therefore, this method may be a promising, low-cost tool for non-invasive assessment of the ventilatory thresholds in cardiac disease.

BACKGROUND:Exercise training is included in cardiac rehabilitation programs to enhance physical capacity and cardiovascular function. Among the existing rehabilitation programs, exercises in water are increasingly prescribed. However, it has been questioned whether exercises in water are safe and relevant in patients with stable chronic heart failure (CHF), coronary artery disease (CAD) with normal systolic left ventricular function. The goal was to assess whether a rehabilitation program, including water-based gymnastic exercises, is safe and induces at least similar benefits as a traditional land-based training. METHODS AND RESULTS:Twenty-four male CAD patients and 24 male CHF patients with stable clinical status participated in a 3-week rehabilitation. They were randomized to either a group performing the training program totally on land (CADl, CHFl; endurance + callisthenic exercises) or partly in water (CADw, CHFw; land endurance + water callisthenic exercises). Before and after rehabilitation, left ventricular systolic and cardiorespiratory functions, hemodynamic variables and autonomic nervous activities were measured. No particular complications were associated with both of our programs. At rest, significant improvements were seen in CHF patients after both types of rehabilitation (increases in stroke volume and left ventricular ejection fraction [LVEF]) as well as a decrease in heart rate (HR) and in diastolic arterial pressure. Significant increases in peaks VO(2), HR, and power output were observed in all patients after rehabilitation in exercise test. The increase in LVEF at rest, in HR and power output at the exercise peak were slightly higher in CHFw than in CHFl. CONCLUSIONS:Altogether, both land and water-based programs were well tolerated and triggered improvements in cardiorespiratory function.

PURPOSE:Rehabilitation programs increasingly involve immersed exercising, including inpatients suffering from severe cardiovascular diseases such as coronary artery disease (CAD) or chronic heart failure (CHF). The hemodynamic responses to short-term head-out water immersion are not well defined in these diseases. This study was aimed at evaluating (1) the cardiac and peripheral hemodynamic responses to short-term head-out water immersion in patients with CHF (n = 12) and CAD (n = 12) and (2) the effect of a rehabilitation program on these responses.METHODS:Wrist arterial tonometry was performed in the upright posture before and during immersion (1.30-m depth) once before and once after a 3-week rehabilitation program including gymnic water exercises.RESULTS:In patients with CAD, water immersion triggered a significant increase in stroke volume, cardiac output, and pulse pressure and a significant decrease in pulse rate, diastolic blood pressure, and systemic vascular resistances, both before and after the rehabilitation program. In patients with CHF, no significant immersion-linked changes in cardiovascular variables were observed before rehabilitation. However, after completion of the rehabilitation program, it was found that water immersion caused significant increases in stroke volume, cardiac output, and pulse pressure.CONCLUSION:In patients with CHF, this 3-week rehabilitation program restored the usual central responses to head-out water immersion (increase in stroke volume and cardiac output). In both patients with CHF and CAD, acute water immersion did not change arterial compliance.

Background Rehabilitation programs involving immersed exercises are more and more frequently used, with severe cardiac patients as well. Design This study investigated whether a rehabilitation program including water-based exercises has additional effects on the cardiovascular system compared with a traditional land-based training in heart disease patients. Methods Twenty-four male stable chronic heart failure patients and 24 male coronary artery disease patients with preserved left ventricular function participated in the study. Patients took part in the rehabilitation program performing cycle endurance exercises on land. They also performed gymnastic exercises either on land (first half of the participants) or in water (second half). Resting plasma concentration of nitric oxide metabolites (nitrate and nitrite) and catecholamine were evaluated, and a symptom-limited exercise test on a cycle ergometer was performed before and after the rehabilitation program. Results In the groups performing water-based exercises, the plasma concentration of nitrates was significantly increased (P = 0.035 for chronic heart failure and P = 0.042 for coronary artery disease), whereas it did not significantly change in the groups performing gymnastic exercise on land. No changes in plasma catecholamine concentration occurred. Conclusion In every group, the cardiorespiratory capacity of patients was significantly increased after rehabilitation. The water-based exercises seemed to effectively increase the basal level of plasma nitrates. Such changes may be related to an enhancement of endothelial function and may be of importance for the health of the patients. Eur J Cardiovasc Prev Rehabil 16:215-221 © 2009 The European Society of Cardiology

Among rugby players, forward and back players showed differences in several isokinetic parameters. Accurate knowledge of the equilibrium between the knee's effector muscles is important for stability of the joint, to not only minimize articular accidents but also pinpoint force imbalances, thereby preventing muscular lesions during the sports season.

Notre travail consiste à évaluer le profil isocinétique des muscles fléchisseurs et extenseurs du genou chez une population de joueurs de rugby. Étude transversale. Les sportifs bénéficient d'une évaluation isocinétique bilatérale du genou sur un dynamomètre isocinétique CONTREX à quatre vitesses angulaires : 90, 120, 180 et 240°/sec en mode concentrique. Le moment maximal, la puissance moyenne, le travail moyen rapporté au poids et le ratio ischiojambiers/quadriceps sont les paramètres isocinétiques retenus. Les tests sont effectués sur 16 joueurs de rugby de Fédérale 1 (troisième division nationale, derrière les deux divisions « élites »), âgés de 25 ans en moyenne avec des extrêmes allant de 20 à 33 ans. Ces sportifs sont divisés en deux groupes : les joueurs avants (pilier, talonneur, deuxième ligne, troisième ligne) et les joueurs arrières (demi de mêlée, demi d'ouverture, centre, ailier, arrière). Les valeurs de paramètres isocinétiques étudiés ne font pas apparaître l'usage d'un membre préférentiel. Le moment maximal et la puissance moyenne sont plus élevés chez les joueurs avants. Nous avons pu constater qu'il existe des différences entre les joueurs avants et arrières au niveau de plusieurs paramètres isocinétiques. La connaissance précise de l'équilibre entre les muscles effecteurs du genou est un apport essentiel à la stabilité de cette articulation, afin de minimiser la survenue d'accidents articulaires, mais également pour déterminer les déséquilibres des forces prévenant ainsi les lésions musculaires au cours de la saison sportive. We aimed to assess the isokinetic profile of the flexor and extensor muscles of the knee within a population of rugby players. This was a descriptive study. The rugby players underwent bilateral isokinetic assessment of knee flexion and extension on a CON-TREX MJ isokinetic dynamometer functioning at four angular frequencies — 90, 120, 180 and 240°/s — in a concentric manner. The isokinetic parameters were peak torque, mean power, and mean work in relation to weight and femoral bicep: quadriceps ratio. The population included 16 “Federal 1” (semi-professional) rugby players with mean age 25 years (range 20–33 years). The players were divided into two groups: “forward” players (props, hookers, second line, third line) and “back” players (scrum, inside, center, wing, tail). The values of the isokinetic parameters did not reveal use of a preferred limb. Consequently, peak torque and mean power were higher in forward players than back players, whereas back players showed a higher relative power throughout the isokinetic test. Among rugby players, forward and back players showed differences in several isokinetic parameters. Accurate knowledge of the equilibrium between the knee's effector muscles is important for stability of the joint, to not only minimize articular accidents but also pinpoint force imbalances, thereby preventing muscular lesions during the sports season.