Erik H. J. Hulzebos

Exercise Performance in Patients With End-Stage Heart Failure After Implantation of a Left Ventricular Assist Device and After Heart Transplantation An Outlook for Permanent Assisting?

OBJECTIVES We sought to study exercise capacity at different points in time after left ventricular assist device (LVAD) implantation and subsequent heart transplantation (HTx). BACKGROUND The lack of donor organs warrants alternatives for transplantation. METHODS Repeat treadmill testing with respiratory gas analysis was performed in 15 men with a LVAD. Four groups of data are presented. In group A (n = 10), the exercise capacities at 8 weeks and 12 weeks after LVAD implantation were compared. In group B (n = 15), the data at 12 weeks are presented in more detail. In group C (n = 9), sequential analysis of exercise capacity was performed at 12 weeks after LVAD implantation and at 12 weeks and one year after HTx. In group D, exercise performance one year after HTx in patients with (n = 10) and without (n = 20) a previous assist device was compared. RESULTS In group A, peak oxygen consumption (Vo2) increased from 21.3+/-3.8 to 24.2+/-4.8 ml/kg body weight per min (p < 0.003), accompanied by a decrease in peak minute ventilation/ carbon dioxide production (VE/Vco2) (39.4+/-10.1 to 36.3+/-8.2; p < 0.03). In group B, peak Vo2 12 weeks after LVAD implantation was 23.0+/-4.4 ml/kg per min. In group C, levels of peak Vo2 12 weeks after LVAD implantation and 12 weeks and one year after HTx were comparable (22.8+/-5.3, 24.6+/-3.3 and 26.2+/-3.8 ml/kg per min, respectively; p = NS). In group D, there appeared to be no difference in percent predicted peak Vo2 in patients with or without a previous LVAD (68+/-13% vs. 74+/-15%; p < 0.37), although, because of the small numbers, the power of this comparison is limited (0.45 to detect a difference of 10%). CONCLUSIONS Exercise capacity in patients with a LVAD increases over time; 12 weeks after LVAD implantation, Vo2 is comparable to that at 12 weeks and one year after HTx. Previous LVAD implantation does not seem to adversely affect exercise capacity after HTx.

Feasibility of preoperative inspiratory muscle training in patients undergoing coronary artery bypass surgery with a high risk of postoperative pulmonary complications: a randomized controlled pilot study

Objective: To determine in a pilot study the feasibility and effects of preoperative inspiratory muscle training in patients at high risk of postoperative pulmonary complications who were scheduled for coronary artery bypass graft surgery. Design: Single-blind, randomized controlled pilot study. Setting: University Medical Centre Utrecht, the Netherlands. Subjects: Twenty-six patients at high risk of postoperative pulmonary complications were selected. Intervention: The intervention group (N = 14) received 2-4 weeks of preoperative inspiratory muscle training on top of the usual care received by the patients in the control group. Main measures: Primary outcome variables of feasibility were the occurrence of adverse events, and patient satisfaction and motivation. Secondary outcome variables were postoperative pulmonary complications and length of hospital stay. Results: The feasibility of inspiratory muscle training was good and no adverse events were observed. Treatment satisfaction and motivation, scored on 10-point scales, were 7.9 (± 0.7) and 8.2 (± 1.0), respectively. Postoperative atelectasis occurred in significantly fewer patients in the intervention group than in the control group (ϰ2 DF1 = 3.85; P = 0.05): Length of hospital stay was 7.93 (± 1.94) days in the intervention group and 9.92 (± 5.78) days in the control group (P = 0.24). Conclusion: Inspiratory muscle training for 2-4 weeks before coronary artery bypass graft surgery was well tolerated by patients at risk of postoperative pulmonary complications and prevented the occurrence of atelectasis in these patients. A larger randomized clinical trial is warranted.

Statement on Exercise Testing in Cystic Fibrosis.

This statement summarizes the information available on specific exercise test protocols and outcome parameters used in patients with cystic fibrosis (CF) and provides expert consensus recommendations for protocol and performance of exercise tests and basic interpretation of results for clinicians. The conclusions were reached employing consensus meetings and a wide-band Delphi process. Although data on utility are currently limited, standardized exercise testing provides detailed information on physiological health, allows screening for exercise-related adverse reactions and enables exercise counselling. The Godfrey Cycle Ergometer Protocol with monitoring of oxygen saturation and ventilatory gas exchange is recommended for exercise testing in people 10 years and older. Cycle ergometry only with pulse oximetry using the Godfrey protocol or treadmill exercise with pulse oximetry - preferably with measurement of gas exchange - are second best options. Peak oxygen uptake, if assessed, and maximal work rate should be reported as the primary measure of exercise capacity. The final statement was reviewed by the European Cystic Fibrosis society and revised based on the comments received. The document was endorsed by the European Respiratory Society.

Near‐infrared spectroscopy during exercise and recovery in children with juvenile dermatomyositis

Introduction: We hypothesized that microvascular disturbances in muscle tissue play a role in the reduced exercise capacity in juvenile dermatomyositis (JDM). Methods: Children with JDM, children with juvenile idiopathic arthritis (clinical controls), and healthy children performed a maximal incremental cycloergometric test from which normalized concentration changes in oxygenated hemoglobin (Δ[O2Hb]) and total hemoglobin (Δ[tHb]) as well as the half‐recovery times of both signals were determined from the vastus medialis and vastus lateralis muscles using near‐infrared spectroscopy. Results: Children with JDM had lower Δ[tHb] values in the vastus medialis at work rates of 25%, 50%, 75%, and 100% of maximal compared with healthy children; the increase in Δ[tHb] with increasing intensity seen in healthy children was absent in children with JDM. Other outcome measures did not differ by group. Conclusions: The results suggest that children with JDM may experience difficulties in increasing muscle blood volume with more strenuous exercise. Muscle Nerve, 2013

Exercise oxidative skeletal muscle metabolism in adolescents with cystic fibrosis

What is the central question of this study? Do intrinsic abnormalities in oxygenation and/or muscle oxidative metabolism contribute to exercise intolerance in adolescents with mild cystic fibrosis? What is the main finding and its importance? This study found no evidence that in adolescents with mild cystic fibrosis in a stable clinical state intrinsic abnormalities in skeletal muscle oxidative metabolism seem to play a clinical significant role. Based on these results, we concluded that there is no metabolic constraint to benefit from exercise training.

Estimating peak oxygen uptake in adolescents with cystic fibrosis

Objectives To predict peak oxygen uptake (VO2peak) from the peak work rate (Wpeak) obtained during a cycle ergometry test using the Godfrey protocol in adolescents with cystic fibrosis (CF), and assess the accuracy of the model for prognostication clustering. Methods Out of our database of anthropometric, spirometric and maximal exercise data from adolescents with CF (N=363; 140 girls and 223 boys; age 14.77±1.73 years; mean expiratory volume in 1 s (FEV1%pred) 86.82±17.77%), a regression equation was developed to predict VO2peak (mL/min). Afterwards, this prediction model was validated with cardiopulmonary exercise data from another 60 adolescents with CF (28 girls, 32 boys; mean age 14.6±1.67 years; mean FEV1%pred 85.43±20.01%). Results We developed a regression model VO2peak (mL/min)=216.3–138.7×sex (0=male; 1=female)+11.5×Wpeak; R2=0.91; SE of the estimate (SEE) 172.57. A statistically significant difference (107 mL/min; p<0.001) was found between predicted VO2peak and measured VO2peak in the validation group. However, this difference was not clinically relevant because the difference was within the SEE of the model. Furthermore, we found high positive predictive and negative predictive values for the model for prognostication clustering (PPV 50–87% vs NPV 82–94%). Conclusions In the absence of direct VO2peak assessment it is possible to estimate VO2peak in adolescents with CF using only a cycle ergometer. Furthermore, the regression model showed to be able to discriminate patients in different prognosis clusters based on exercise capacity.

Development of a framework to describe goals and content of exercise interventions in physical therapy: a mixed method approach including a systematic review

Abstract Background: Exercise interventions in physical therapy (PT) are often not well described in research reports. Omitting details of the intervention hampers the transfer to daily clinical practice. Objective: To develop a framework for describing goals and content of exercise interventions, in order to provide structured and detailed information for use in research reports. Methods: A framework was developed in three steps using a mixed method approach. First, the scientific literature was systematically searched for available methods to describe PT interventions. An inventory of these methods was made and relevant elements were extracted. Second, based on the results of the literature search, a global framework was developed by a focus group of experts in the field of PT. Third, the framework was field tested by describing four different exercise interventions, leading to a final version. Results: In the developed framework intervention goals at the level of body functions and activities/participation were listed using the International Classification of Functioning, Disability and Health. To guide the description of the content of the exercise intervention a list of intervention details was developed, which was derived from an existing classification of PT interventions. Goals and content of exercise interventions were linked. Field testing of the framework led to adequate descriptions of exercise interventions. Conclusion: The developed framework is a promising first step in offering a feasible guide for a structured and detailed description of goals and content of exercise interventions within research reports.

Measurement of physical activity in patients with cystic fibrosis: a systematic review.

Physical activity (PA) improves exercise capacity, slower decline in lung function and improve quality of life in patients with cystic fibrosis (CF). Despite the importance of PA, it is important to assess the amount of PA. The objective of this literature review was to evaluate the validity and usability of instruments that are used to measure PA in patients with CF. GoogleScholar, ScienceDirect, The Cochrane Library and PUBMED database were searched. All studies that included instruments to measure PA of patients with CF, published from 2000 till June 2012 were reviewed. Eight studies were included in this systematic review. At this moment, there is not sufficient evidence to support incorporation of specific tools to facilitate the PA assessment into clinical practice. Pedometers may offer an inexpensive method of obtaining a measurement of PA, and there is some evidence for supporting its use in CF.

Cardiopulmonary Exercise Testing in Pediatrics

&NA; Aerobic fitness is an important determinant of overall health. Higher aerobic fitness has been associated with many health benefits. Because myocardial ischemia is rare in children, indications for exercise testing differ in children compared with adults. Pediatric exercise testing is imperative to unravel the physiological mechanisms of reduced aerobic fitness and to evaluate intervention effects in children and adolescents with a chronic disease or disability. Cardiopulmonary exercise testing includes the measurement of respiratory gas exchange and is the gold standard for determining aerobic fitness, as well as for examining the integrated physiological responses to exercise in pediatric medicine. As the physiological responses to exercise change during growth and development, appropriate pediatric reference values are essential for an adequate interpretation of the cardiopulmonary exercise test.