Combined endurance/resistance training early on, after a first myocardial infarction, does not induce negative left ventricular remodelling

BACKGROUND: Resistance training (RT) is safe and practicable in low-risk populations with coronary artery disease. In patients with left ventricular (LV) dysfunction after an acute ischaemic event, few data exist about the impact of RT on LV remodelling. METHODS: In this prospective, randomized, controlled study, 38 patients, after a first myocardial infarction and a maximum ejection fraction (EF) of 45%, were assigned either to combined endurance training (ET)/RT (n=17; 15 men; 54.7+/-9.4 years and EF: 40.3+/-4.5%) or to ET alone (n=21; 17 men; 57.0+/-9.6 years and EF: 41.9+/-4.9%) for 12 weeks. ET was effectuated at an intensity of 70-85% of peak heart rate; RT, between 40 and 60% of the one-repetition maximum. LV remodelling was assessed by MRI. RESULTS: No statistically significant differences between the groups in the changes of end-diastolic volume (P=0.914), LV mass (P=0.885) and EF (P=0.763) were observed. Over 1 year, the end-diastolic volume increased from 206+/-41 to 210+/-48 ml (P=0.379) vs. 183+/-44 to 186+/-52 ml (P=0.586); LV mass from 149+/-28 to 155+/-31 g (P=0.408) vs. 144+/-36 to 149+/-42 g (P=0.227) and EF from 49.1+/-12.3 to 49.3+/-12.0% (P=0.959) vs. 51.5+/-13.1 to 54.1% (P=0.463), in the ET/RT and ET groups, respectively. Peak VO2 and muscle strength increased significantly in both groups, but no difference between the groups was noticed. CONCLUSION: RT with an intensity of up to 60% of the one-repetition maximum, after an acute myocardial infarction, does not lead to a more pronounced LV dilatation than ET alone. A combined ET/RT, or ET alone, for 3 months can both increase the peak VO2 and muscle strength significantly.

Methodological approach to the first and second lactate threshold in incremental cardiopulmonary exercise testing

Determination of an 'anaerobic threshold' plays an important role in the appreciation of an incremental cardiopulmonary exercise test and describes prominent changes of blood lactate accumulation with increasing workload. Two lactate thresholds are discerned during cardiopulmonary exercise testing and used for physical fitness estimation or training prescription. A multitude of different terms are, however, found in the literature describing the two thresholds. Furthermore, the term 'anaerobic threshold' is synonymously used for both, the 'first' and the 'second' lactate threshold, bearing a great potential of confusion. The aim of this review is therefore to order terms, present threshold concepts, and describe methods for lactate threshold determination using a three-phase model with reference to the historical and physiological background to facilitate the practical application of the term 'anaerobic threshold'.

Depression and anxiety symptoms affect change in exercise capacity during cardiac rehabilitation

BACKGROUND: To study whether symptoms of depression and anxiety would affect changes in exercise capacity and body mass index (BMI) during rehabilitation. DESIGN: Comprehensive cardiac outpatient rehabilitation intervention program. METHODS: We investigated exercise capacity, BMI, and symptoms of depression and anxiety before and after cardiac rehabilitation in 114 patients with coronary artery disease. The Hospital Anxiety and Depression Scale (HADS) was applied to assess symptoms of depression (HADS-D) and anxiety (HADS-A). RESULTS: Exercise capacity increased (127+/-47 vs. 144+/-51 watts, P<0.001) and symptoms of depression (4.0+/-3.6 vs. 2.7+/-2.7, P<0.001) and anxiety (5.4+/-4.4 vs. 4.1+/-3.6, P<0.001) decreased with the program, whereas BMI did not change. After controlling for covariates, HADS-D (r=-0.19, P=0.47) and HADS-A (r=0.17, P<0.09) correlated with change in exercise capacity. Change in HADS-A also correlated with that in exercise capacity (r=0.18, P<0.06). Changes in depression and anxiety were not significantly related to those in BMI. CONCLUSION: Symptoms of depression and anxiety affected change in exercise capacity during cardiac rehabilitation. Depressive symptoms may impair improvement in exercise capacity, thereby mitigating the cardiovascular benefit achieved by cardiac rehabilitation programs.

Influence of exertional oscillatory ventilation on exercise performance in heart failure

BACKGROUND: Exertional oscillatory ventilation (EOV) in heart failure may potentiate the negative effects of low cardiac output and high ventilation on exercise performance. We hypothesized that the presence of EOV might, per se, influence exercise capacity as evaluated by maximal cardiopulmonary exercise test. METHODS AND RESULTS: We identified 78 severe chronic heart failure patient pairs with and without EOV. Patients were matched for sex, age and peak oxygen consumption (VO2). Patients with EOV showed, for the same peak VO2, a lower workload (WL) at peak (DeltaWatts=5.8+/-23.0, P=0.027), a less efficient ventilation (higher VE/VCO2 slope: 38.0+/-8.3 vs. 32.8+/-6.3, P<0.001), lower peak exercise tidal volume (1.49+/-0.36 L vs. 1.61+/-0.46 L, P=0.015) and higher peak respiratory rate (34+/-7/min vs. 31+/-6/min, P=0.002). In 33 patients, EOV disappeared during exercise, whereas in 45 patients EOV persisted. Fifty percent of EOV disappearing patients had an increase in the VO2/WL relationship after EOV regression, consistent with a more efficient oxygen delivery to muscles. No cardiopulmonary exercise test parameter was associated with the different behaviour of VO2/WL. CONCLUSION: The presence of EOV negatively influences exercise performance of chronic heart failure patients likely because of an increased cost of breathing. EOV disappearance during exercise is associated with a more efficient oxygen delivery in several cases.

The use of intramedullary helix wire for the treatment of proximal humerus fractures

OBJECTIVE: To present the functional and radiographic outcome 1 and 6 years after application of a new intramedullary fixation device for proximal humerus fractures. DESIGN: Retrospective case series. SETTING: Level II orthopaedic surgery hospital. PATIENTS: Twenty-six consecutive patients (average age 68.9 years) with 2-, 3- and 4-part fractures of the proximal humerus were operated at a single institution. Follow-up was performed after 1 year (26 patients) and 6 years (16 patients). INTERVENTION: All patients were treated with closed reduction and intramedullary helix wires. MAIN OUTCOME MEASUREMENTS: The Constant-Murley score and the University of California Los Angeles (UCLA) score. Clinical complications and radiological posttraumatic arthritis were recorded. RESULTS: The average Constant-Murley score was 70.3 (points) and 70.7 after 1 and 6 years, respectively; the average UCLA score was 27.2 and 31.5 after 1 and 6 years, respectively. Major complications were 4 revisions for 3 secondary fragment displacements and 1 nonunion with partial avascular osteonecrosis in the first postoperative year. Complications were found predominantly in 4-part fractures (3/5, 60%). There were no further complications or progressive posttraumatic arthritis up to 6 years following surgery. CONCLUSION: The helix wire is well suited for displaced or unstable 2- and 3-part proximal humerus fractures. Adequate functional outcome, a low number of implant displacements, a low number of application morbidity, and infrequent implant removals were recorded. The use of this device is not recommended for 4-part fractures.

Comparing remote sensing and ground-based methods of quantifying cover type and carbon storage in an urban forest

Understanding the canopy cover of an urban environment leads to better estimates of carbon storage and more informed management decisions by urban foresters. The most commonly used method for assessing urban forest cover type extent is ground surveys, which can be both timeconsuming and expensive. The analysis of aerial photos is an alternative method that is faster, cheaper, and can cover a larger number of sites, but may be less accurate. The objectives of this paper were (1) to compare three methods of cover type assessment for Los Angeles, CA: handdelineation of aerial photos in ArcMap, supervised classification of aerial photos in ERDAS Imagine, and ground-collected data using the Urban Forest Effects (UFORE) model protocol; (2) to determine how well remote sensing methods estimate carbon storage as predicted by the UFORE model; and (3) to explore the influence of tree diameter and tree density on carbon storage estimates. Four major cover types (bare ground, fine vegetation, coarse vegetation, and impervious surfaces) were determined from 348 plots (0.039 ha each) randomly stratified according to land-use. Hand-delineation was better than supervised classification at predicting ground-based measurements of cover type and UFORE model-predicted carbon storage. Most error in supervised classification resulted from shadow, which was interpreted as unknown cover type. Neither tree diameter or tree density per plot significantly affected the relationship between carbon storage and canopy cover. The efficiency of remote sensing rather than in situ data collection allows urban forest managers the ability to quickly assess a city and plan accordingly while also preserving their often-limited budget.

Relation of heart rate recovery to psychological distress and quality of life in patients with chronic heart failure

BACKGROUND: Psychological distress, poor disease-specific quality of life (QoL), and reduction in vagally mediated early heart rate recovery (HRR) after exercise, all previously predicted morbidity and mortality in patients with chronic heart failure (CHF). We hypothesized lower HRR with greater psychological distress and poorer QoL in CHF. DESIGN: All assessments were made at the beginning of a comprehensive cardiac outpatient rehabilitation intervention program. METHODS: Fifty-six CHF patients (mean 58+/-12 years, 84% men) completed the Hospital Anxiety and Depression Scale and the Minnesota Living With Heart Failure Questionnaire. HRR was determined as the difference between HR at the end of exercise and 1 min after exercise termination (HRR-1). RESULTS: Elevated levels of anxiety symptoms (P=0.005) as well as decreased levels of the Minnesota Living With Heart Failure Questionnaire total (P = 0.025), physical (P=0.026), and emotional (P=0.017) QoL were independently associated with blunted HRR-1. Anxiety, total, physical, and emotional QoL explained 11.4, 8, 7.8, and 9.0%, respectively, of the variance after controlling for covariates. Depressed mood was not associated with HRR-1 (P=0.20). CONCLUSION: Increased psychological distress with regard to elevated anxiety symptoms and impaired QoL were independent correlates of reduced HRR-1 in patients with CHF. Reduced vagal tone might explain part of the adverse clinical outcome previously observed in CHF patients in relation to psychological distress and poor disease-specific QoL.