Continuous non-invasive estimates of cerebral blood flow using electrocardiography signals: a feasibility study.

This paper describes a potential method to detect changes in cerebral blood flow (CBF) using electrocardiography (ECG) signals, measured across scalp electrodes with reference to the same signal across the chest-a metric we term the Electrocardiography Brain Perfusion index (EBPi). We investigated the feasibility of EBPi to monitor CBF changes in response to specific tasks. Twenty healthy volunteers wore a head-mounted device to monitor EBPi and electroencephalography (EEG) during tasks known to alter CBF. Transcranial Doppler (TCD) ultrasound measurements provided ground-truth estimates of CBF. Statistical analyses were applied to EBPi, TCD right middle cerebral artery blood flow velocity (rMCAv) and EEG relative Alpha (rAlpha) data to detect significant task-induced changes and correlations. Breath-holding and aerobic exercise induced highly significant increases in EBPi and TCD rMCAv (p < 0.01). Verbal fluency also increased both measures, however the increase was only significant for EBPi (p < 0.05). Hyperventilation induced a highly significant decrease in TCD rMCAv (p < 0.01) but EBPi was unchanged. Combining all tasks, EBPi exhibited a highly significant, weak positive correlation with TCD rMCAv (r = 0.27, p < 0.01) and the Pearson coefficient between EBPi and rAlpha was r = - 0.09 (p = 0.05). EBPi appears to be responsive to dynamic changes in CBF and, can enable practical, continuous monitoring. CBF is a key parameter of brain health and function but is not easily measured in a practical, continuous, non-invasive fashion. EBPi may have important clinical implications in this context for stroke monitoring and management. Additional studies are required to support this claim. Supplementary Information: The online version contains supplementary material available at 10.1007/s13534-023-00265-z.

Ultrasound assessment of the inferior glenohumeral capsule in normal shoulders-a study of measurement variables and reliability.

OBJECTIVES: To establish the reliability of a standardised ultrasound protocol to measure normal inferior glenohumeral capsule (IGHC) thickness and to investigate the effects of age, sex, hand dominance and angles of abduction on the thickness. METHODS: IGHC images were obtained at 60o, 90o and 180o abduction angles of 151 asymptomatic shoulders in supine position. Following the proposed guidelines, three sonographers blindly measured the IGHC thicknesses for intra- and interrater reliability assessments. RESULTS: The intrarater reliability was excellent (intraclass correlation coefficient value = 0.95; 95% CI = 0.92-0.97). The interrater reliability was moderate (intraclass correlation coefficient value = 0.74; 95% CI = 0.60-0.83). The mean IGHC thickness values in mm ± SD at 60o, 90o and 180o abduction angles for males were 3.3 ± 0.93, 3.0 ± 0.80 and 2.6 ± 0.55 and those for females were 2.7 ± 0.86, 2.4 ± 0.7 and 2.0 ± 0.56 respectively. Although males had thicker IGHC, the rate at which the thickness reduced with increased abduction was same in both males and females. Age and hand dominance had no effect. CONCLUSION: The normal IGHC thickness varies with sex and the abduction angle of the arm at which it is measured. A large variation of IGHC thickness exists in the normal population. ADVANCES IN KNOWLEDGE: The results of this study discourage the use of a single value of IGHC thickness and emphasise the importance of comparing the thickness of the symptomatic side to that of the asymptomatic side of the same subject at the same abduction level. The guidelines provided in this study can be used in clinical practice and in future research studies.

Ultrasound Features for the Diagnosis of Adhesive Capsulitis/Frozen Shoulder: A Systematic Review.

While ultrasound has become a preferred tool for musculoskeletal imaging, differing ultrasound findings that have been reported in patients with adhesive capsulitis can create confusion and misconceptions. This systematic review was aimed at summarizing all the ultrasound features currently described in the literature and providing a critical analysis of the sources to allow the readers to make a well-informed decision on the reliability of these features in the diagnosis of this condition. Databases were searched for original studies up to August 2021. Twenty-three studies were included. The QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2) tool was used to assess the quality of each selected article. Fourteen ultrasound features were identified. A quality analysis of all ultrasound features was performed using the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) framework. All studies exhibited considerable heterogeneity in investigated ultrasound features and methodologies employed; therefore, meta-analysis was not considered to be appropriate. Hence, narrative synthesis was performed. The overall quality of each ultrasound outcome was found to be of "low" to "very low" level, and the generalisability of the results was also thought to be limited. Cautious interpretation and clinical correlation are recommended while applying these ultrasound features in clinical practice.

A snapshot of venous ultrasound examinations in Australia and New Zealand: Implications for diagnosis and management of chronic venous disease interventions.

Objective: Chronic venous disease is a common vascular condition, affecting up to 60% of the population worldwide. In Australia and New Zealand, chronic venous insufficiency ultrasound examinations are primarily performed by sonographers. This research aimed to explore how ultrasound examinations are being performed, providing insights into current practices and recommendations for quality improvement. Method: A questionnaire was distributed to capture demographics, practices of ultrasound, examination techniques, the use of nomenclature and experience of the respondents. Results: The analysis of 97 responses showed a heterogeneity in the clinical application of ultrasound. Most sonographers performed less than two scans per day within 30-45 minutes. Deep venous incompetence was routinely excluded by all respondents. The majority used standing, sitting and reverse Trendelenburg position except for a few using supine position. Manual augmentation was the preferred provocation manoeuvre. Anatomical variations at the junctional level were not adequately evaluated. Although Giacomini's vein was assessed by 80%, 57% of those did not evaluate paradoxical reflux. Seventy-five per cent routinely assessed non-saphenous reflux; however, over 50% were unfamiliar with lymph node venous networks. A significant number of out-dated venous terms were still being used. A low participation rate in continuing professional development was identified, which might be attributable to limited education and training programs. Conclusion: The study is a multi-faceted exploration that identified a need for standardized diagnostic and reporting guidelines. Our results could explain discrepancies in diagnostic findings and inconsistencies in the use of medical terminology, with implications for clinical decision making and assessment of surgical outcome.

Brief report: Passive mechanical properties of gastrocnemius in multiple sclerosis and ankle contracture.

BACKGROUND: Ankle contracture is common in people with multiple sclerosis (MS) but the mechanisms of contracture are not clear. This study aimed to identify the mechanisms of contracture in MS by comparing passive muscle length and stiffness at known tension, separated into contributions by muscle fascicles and tendons, between people with MS who had contracture and healthy people. METHODS: Passive length-tension curves of the gastrocnemius muscle-tendon unit were derived from passive ankle torque and angle using a published biomechanical method. Ultrasound images of medial gastrocnemius muscle fascicles were used to partition length-tension curves into fascicle and tendon components. Lengths and stiffness of the muscle-tendon unit, muscle fascicles and tendons were compared between groups with linear regression. FINDINGS: Data were obtained from 15 participants with MS who had contracture [age 53 (12) years, mean (SD)] and 25 healthy participants [48 (20) years]. Participants with MS had clinically significant ankle contracture, and had shorter fascicles at slack length (between-groups mean difference -0.8 cm, 95% CI -1.2 to -0.4 cm, p < 0.001) and at 100 N (-0.7 cm, 95% CI -1.3 to -0.1 cm, p = 0.02) compared to healthy participants. There were no differences between groups in all other outcomes. INTERPRETATION: Tension-referenced comparisons of passive muscle length and stiffness show that people with MS who had contracture had shorter fascicles at low and high tension compared to healthy people, but there were no changes to the muscle-tendon unit or tendon. Further studies are needed to identify the causes and mechanisms of contracture in neurological conditions.

Relationship between echocardiogram and physical parameters in experienced resistance trainers: a pilot study.

BACKGROUND: A paucity of research exists concerning physiological factors influencing heart structure and function in strength athletes. This pilot study investigated whether body composition and muscle performance are associated with indices of cardiac structure and function in experienced resistance trainers. METHODS: A cross-sectional study designed was employed to address the study aim. Seventeen males (median age 33.0 years) and eight females (median age 32.5 years) with backgrounds in bodybuilding and powerlifting participated in this study. Muscle performance, body composition and echocardiographic measures were performed. Mann-Whitney U-tests were used to examine differences between males and females. Spearman's Rho partial correlation analyses (adjusting for sex) were conducted to examine relationships between physical and echocardiogram parameters. RESULTS: Moderate to strong positive correlations were found between fat-free mass and aortic root, right ventricular internal dimension, interventricular septum thickness, left ventricular posterior wall thickness, left atrium area, left ventricular end-diastolic volume, and left ventricular end-systolic volume (r: 0.43-0.76, P≤0.03). Moderate to strong positive correlations were found between leg press 1RM and aortic root, left ventricular internal dimension diastole, left atrium area, left ventricular end-diastolic volume, and left ventricular end-systolic volume (r: 0.49-0.67, P≤0.02). CONCLUSIONS: Resistance trainers with greater fat-free mass and lower body strength appear to have larger cardiac structures. Changes in heart size and function are likely to result from long-term strenuous resistance training. Due to the suspected prevalence of performance enhancing drug use among powerlifters and bodybuilders, care is required to rule out pathological conditions.

Effect of Training Phase on Physical and Physiological Parameters of Male Powerlifters.

Longitudinal research on training and dietary practices of natural powerlifters is limited. This study investigated the effect of phases of training on physical and physiological parameters in male natural powerlifters. Nine participants completed testing at two time points: (i) preparatory phase (~3 months prior to a major competition) and (ii) competition phase (1-2 weeks from a major competition). No significant changes between training phases were found for muscle strength and power. A trend for significance was found for decreased muscle endurance of the lower body (-24.4%, p = 0.08). A significant increase in leg lean mass was found at the competition phase (2.3%, p = 0.04), although no changes for other body composition measures were observed. No change was observed for any health marker except a trend for increased urinary creatinine clearance at the competition phase (12.5%, p = 0.08). A significant reduction in training volume for the lower body (-75.0%, p = 0.04) and a trend for a decrease in total energy intake (-17.0%, p = 0.06) was observed during the competition phase. Despite modifications in training and dietary practices, it appears that muscle performance, body composition, and health status remain relatively stable between training phases in male natural powerlifters.

Reliability and correlates of cross-sectional area of abductor hallucis and the medial belly of the flexor hallucis brevis measured by ultrasound.

BACKGROUND: Weakness of the intrinsic foot muscles is thought to produce deformity, disability and pain. Assessing intrinsic foot muscles in isolation is a challenge; however ultrasound might provide a solution. The aims of this study were to assess the reproducibility of assessing the size of abductor halluces (AbH) and the medial belly of flexor hallucis brevis (FHBM) muscles, and identify their relationship with toe strength, foot morphology and balance. METHODS: Twenty one participants aged 26-64 years were measured on two occasions for muscle cross-sectional area using a Siemens Acuson X300 Ultrasound System with 5-13 MHz linear array transducer. Great toe flexor strength was measured by pedobarography, the paper grip test and hand-held dynamometry. Foot morphology was assessed by foot length, truncated foot length, Foot Posture Index (FPI) and dorsal arch height. Balance was measured by the maximal step test. Intra-class correlation coefficients (ICC3,1) were used to evaluate intra-rater reliability. Pearson's correlation coefficients were performed to assess associations between muscle size and strength, morphology and balance measures. To account for the influence of physical body size, partial correlations were also performed controlling for truncated foot length. RESULTS: Intra-rater reliability was excellent for AbH (ICC3,1 = 0.97) and FHBM (ICC3,1 = 0.96). Significant associations were found between cross-sectional area of AbH and great toe flexion force measured standing by pedobarography (r = .623, p = .003),), arch height measured sitting (r = .597, p = .004) and standing (r = .590, p = .005), foot length (r = .582, p = 006), truncated foot length (r = .580, p = .006), balance (r = .443, p = .044), weight (r = .662, p = .001), height (r = .559, p = .008), and BMI (r = .502, p = .020). Significant associations were found between cross-sectional area of FHBM and FPI (r = .544, p = .011), truncated foot length (r = .483, p = .027) and foot length (r = .451, p = .040). Significant partial associations were found between AbH and great toe flexion force in standing by pedobarography (r = .562, p = .012) and FHBM and the FPI (r = .631, p = .003). CONCLUSIONS: Measuring the cross-sectional area of AbH and FHBM with ultrasound is reproducible. Measures of strength, morphology and balance appear to relate more to the size of AbH than FHBM. After controlling for physical body size, cross-sectional area of AbH remained a significant correlate of great toe flexor strength and might be a useful biomarker to measure early therapeutic response to exercise.

Reliability and Diagnostic Thresholds for Ultrasound Measurements of Dermal Thickness in Breast Lymphedema.

BACKGROUND: Lymphedema of the breast, secondary to treatment for breast cancer, is difficult to assess due to the shape of the breast and the nature of the tissue. Ultrasound measurement of dermal thickness has been previously used to assess breast swelling; however, the reliability of the measurements, or what should be considered an abnormal thickness, is currently known. METHODS AND RESULTS: Thirty-eight women with breast edema were recruited and underwent assessment using ultrasound. During the assessment, the four quadrants (superior, inferior, medial, and lateral) of the affected and unaffected breasts were imaged three times each. Dermal thickness was then measured by two assessors, on two occasions for each captured image. The interimage, intrarater, and inter-rater reliability was all found to be excellent (Cronbach's alpha = 0.995; ICC(3,1) = 0.962 and 0.851; and ICC(2,1) = 0.977, respectively). A dermal thickness of >1.6 mm in the superior and lateral quadrants and 2.0 mm in the medial and inferior quadrants was determined, by receiver-operating characteristics curve analysis, as the optimal diagnostic threshold to detect breast edema. CONCLUSION: Dermal thickness measurements can be reliably completed on breasts with edema secondary to breast cancer. Future study is needed to determine the utility of the dermal thickness thresholds established as well as to investigate changes in dermal thickness as a response to treatment of breast edema.

The development and validation of a custom built device for assessing frontal knee joint laxity.

INTRODUCTION: This study reports the development and validation of a quantitative technique of assessing frontal knee joint laxity through a custom built device named KLICP. The objectives of this study were to determine: (i) the intra- and inter-rater reliability and (ii) the validity of the device when compared to real time ultrasound. METHODS: Twenty-five participants had their frontal knee joint laxity assessed by the KLICP, by manual varus/valgus tests and by ultrasound. Two raters independently assessed laxity manually by three repeated measurements, repeated at least 48h later. Results were validated by comparing them to the medial and lateral joint space opening measured by the ultrasound. Intraclass correlation coefficients and standard error of measurement reliability were calculated. Pearson's correlation coefficients were calculated to determine the correlation between the KLICP and the joint space. RESULTS: Intra-rater reliability (intra-session) for each rater was good on both sessions (0.91-0.98), intra-rater reliability (inter-sessions) was moderate to good (0.62-0.87), and inter-rater reliability (intra-session) was good (0.75-0.80). There is low agreement for intra-rater (inter-session) and for inter-rater (intra-session) reliability. The KLICP measurement has a significant positive fair to moderate correlation to the ultrasound measurement at the left (r: 0.61, p: 0.01) and right (r: 0.48, p: 0.02) knee in the valgus direction and at the left (r: 0.51, p: 0.01) and right (r: 0.39, p: 0.05) knee in the varus direction. There is low agreement between the KLICP and the RTU. CONCLUSIONS: Reliability and agreement was good only when measured for intra-rater, within session.

Effects of a Modified German Volume Training Program on Muscular Hypertrophy and Strength.

Amirthalingam, T, Mavros, Y, Wilson, GC, Clarke, JL, Mitchell, L, and Hackett, DA. Effects of a modified German volume training program on muscular hypertrophy and strength. J Strength Cond Res 31(11): 3109-3119, 2017-German Volume Training (GVT), or the 10 sets method, has been used for decades by weightlifters to increase muscle mass. To date, no study has directly examined the training adaptations after GVT. The purpose of this study was to investigate the effect of a modified GVT intervention on muscular hypertrophy and strength. Nineteen healthy men were randomly assign to 6 weeks of 10 or 5 sets of 10 repetitions for specific compound resistance exercises included in a split routine performed 3 times per week. Total and regional lean body mass, muscle thickness, and muscle strength were measured before and after the training program. Across groups, there were significant increases in lean body mass measures, however, greater increases in trunk (p = 0.043; effect size [ES] = -0.21) and arm (p = 0.083; ES = -0.25) lean body mass favored the 5-SET group. No significant increases were found for leg lean body mass or measures of muscle thickness across groups. Significant increases were found across groups for muscular strength, with greater increases in the 5-SET group for bench press (p = 0.014; ES = -0.43) and lat pull-down (p = 0.003; ES = -0.54). It seems that the modified GVT program is no more effective than performing 5 sets per exercise for increasing muscle hypertrophy and strength. To maximize hypertrophic training effects, it is recommended that 4-6 sets per exercise be performed, as it seems gains will plateau beyond this set range and may even regress due to overtraining.

Chondroitin sulphate glycosaminoglycans contribute to widespread inferior biomechanics in tendon after focal injury.

Both mechanical and structural properties of tendon change after injury however the causal relationship between these properties is presently unclear. This study aimed to determine the extent of biomechanical change in post-injury tendon pathology and whether the sulphated glycosaminoglycans (glycosaminoglycans) present are a causal factor in these changes. Equine superficial digital flexor tendons (SDF tendons) were surgically-injured in vivo (n=6 injured, n=6 control). Six weeks later they were harvested and regionally dissected into twelve regions around the lesion (equal medial/lateral, proximal/distal). Glycosaminoglycans were removed by enzymatic (chondroitinase) treatment. Elastic modulus (modulus) and ultimate tensile strength (UTS) were measured under uniaxial tension to failure, and tendon glycosaminoglycan content was measured by spectrophotometry. Compared to healthy tendons, pathology induced by the injury decreased modulus (-38%; 95%CI -49% to -28%; P<0.001) and UTS (-38%; 95%CI -48% to -28%; P<0.001) and increased glycosaminoglycan content (+52%; 95%CI 39% - 64%; P<0.001) throughout the tendon. Chondroitinase-mediated glycosaminoglycan removal (50%; 95%CI 21-79%; P<0.001) in surgically-injured pathological tendons caused a significant increase in modulus (5.6MPa/µg removed; 95%CI 0.31-11; P=0.038) and UTS (1.0MPa per µg removed; 95%CI 0.043-2; P=0.041). These results demonstrate that the chondroitin/dermatan sulphate glycosaminoglycans that accumulate in pathological tendon post-injury are partly responsible for the altered biomechanical properties.

Frontomaxillary facial angle measurement in trisomy 21 and euploid fetuses: two- and three-dimensional assessment during routine first trimester screening.

OBJECTIVE: To assess 2D and 3D frontomaxillary facial angle (FMFA) measurements in euploid and trisomy 21 fetuses. MATERIALS AND METHODS: Over a 2-year period, women with singleton pregnancies attending a private prenatal screening and diagnosis practice in Sydney, Australia, were invited to participate in this study where 2D images and 3D volumes of the fetal face were collected during routine first trimester screening. In pregnancies where trisomy 21 was confirmed, FMFA measurements were performed in 2D and 3D and compared with those from a euploid cohort. RESULTS: Overall, 250 women carrying euploid and 22 women carrying trisomy 21 fetuses participated. Trisomy 21 fetuses had significantly larger FMFA measurements than euploid fetuses in both 2D and 3D assessments. 95% of 3D and 100% of 2D FMFA measurements for the trisomy 21 fetuses were above the mean FMFA measurement of the euploid fetuses. There was no relationship between increasing crown-rump length and FMFA measurement. CONCLUSION: 2D and 3D FMFA measurements in trisomy 21 fetuses are statistically greater (p < 0.001) than those in euploid fetuses. This supports FMFA as a possible additional marker for trisomy 21 for first trimester screening.

Development of a method for measuring femoral torsion using real-time ultrasound.

Excessive femoral torsion has been associated with various musculoskeletal and neurological problems. To explore this relationship, it is essential to be able to measure femoral torsion in the clinic accurately. Computerized tomography (CT) and magnetic resonance imaging (MRI) are thought to provide the most accurate measurements but CT involves significant radiation exposure and MRI is expensive. The aim of this study was to design a method for measuring femoral torsion in the clinic, and to determine the reliability of this method. Details of design process, including construction of a jig, the protocol developed and the reliability of the method are presented. The protocol developed used ultrasound to image a ridge on the greater trochanter, and a customized jig placed on the femoral condyles as reference points. An inclinometer attached to the customized jig allowed quantification of the degree of femoral torsion. Measurements taken with this protocol had excellent intra- and inter-rater reliability (ICC2,1 = 0.98 and 0.97, respectively). This method of measuring femoral torsion also permitted measurement of femoral torsion with a high degree of accuracy. This method is applicable to the research setting and, with minor adjustments, will be applicable to the clinical setting.

Left ventricular systolic function in HER2/neu negative breast cancer patients treated with anthracycline chemotherapy: a comparative analysis of left ventricular ejection fraction and myocardial strain imaging over 12 months.

AIM: Anthracycline agents are undermined by their cardiotoxicity. As life expectancy following treatment is greatly improved, techniques that ensure early detection and timely management of cardiotoxicity are essential. The aim of the present study was to evaluate left ventricular (LV) systolic function with LV ejection fraction (LVEF) and two-dimensional myocardial strain up to 12 months after anthracycline chemotherapy, specifically in HER2/neu negative breast cancer patients. METHODS: Seventy-eight consecutive anthracycline naïve breast cancer patients were studied before and immediately after anthracycline chemotherapy. Fifty HER2/neu negative patients were studied over 12 months with serial echocardiograms at four time points. All patients were treated with standard regimens containing anthracyclines. RESULTS: Global systolic strain was significantly reduced immediately after, and 6 months after anthracyclines (-19.0 ± 2.3% to -17.5 ± 2.3% (P<0.001) and -18.2 ± 2.2% (P=0.01) respectively). A non-uniform reduction in strain was observed each time with relative sparing of the LV apex. LVEF remained largely unchanged at both time points. Global strain normalised by 12 months in the majority of patients. Persistently reduced strain was observed in 16% (n=8); these patients had a greater reduction in strain at 6 months (≤ -17.2%), and had received higher cumulative anthracycline doses. CONCLUSION: Myocardial strain imaging is more sensitive than LVEF for the early detection and intermediate term monitoring of LV systolic function following anthracycline chemotherapy in HER2/neu negative breast cancer patients, and may aid in the development of improved monitoring protocols.

Frontomaxillary facial angle measurement at 11-14 weeks: assessment of interobserver and intraobserver agreement in 2D and 3D imaging.

INTRODUCTION: The primary aim of this study was to assess the interobserver and intraobserver reproducibility of the first-trimester frontomaxillary facial angle (FMFA) measurement using both 2D and 3D ultrasound. Assessment of the relationship between crown-to-rump length (CRL) and FMFA measurement was also reviewed. MATERIALS AND METHODS: Two experienced operators imaged the same 30 patients over a 1-month period collecting both 2D static images and 3D volumes during nuchal translucency assessment at 11-14 weeks' gestation. The operators were blinded to each other's images and results. RESULTS: The mean 2D FMFA measurement was 88.0° and 88.4° for observer 1 and 2, respectively; while the mean 3D FMFA measurement was 87.8° and 88.0°, respectively. Intraclass correlation suggests good intraobserver and interobserver agreement with no statistically significant difference between operators in either 2D (p = 0.14) or 3D (p = 0.11) measurements. The FMFA was unchanged with increasing CRL. DISCUSSION: Both 2D and 3D FMFA measurements have been demonstrated to be equivalent and reliable. Strict image acquisition criteria must be followed for accurate and reproducible FMFA measurements. There was no change demonstrated in FMFA measurement with increasing CRL.

Altered left ventricular longitudinal diastolic function correlates with reduced systolic function immediately after anthracycline chemotherapy.

AIMS: The benefits from anthracycline chemotherapy are undermined by potentially life-threatening cardiotoxicity. Transthoracic echocardiography is the most commonly used method for monitoring cardiotoxicity, and centres on the measurement of left ventricular systolic function. The aim of this study was to utilize two-dimensional speckle tracking echocardiography (2DSTE) at baseline and immediately after anthracycline chemotherapy to investigate whether patients with significant changes in systolic function after anthracycline therapy would also develop alterations in diastolic parameters. METHODS AND RESULTS: Fifty-two women with histologically confirmed breast cancer were prospectively recruited. Echocardiograms were performed 1 week prior to and 1 week following chemotherapy (always before adjuvant trastuzumab or thoracic radiotherapy). Conventional Doppler, tissue velocity imaging (TVI), and 2DSTE were used to measure diastolic function. 2DSTE measurements included longitudinal diastolic strain, early (E-Sr), and late (A-Sr) myocardial strain rate. 2DSTE and left ventricular ejection fraction (LVEF) were used to measure longitudinal systolic function. Altered LV diastolic function (including E-Sr) was observed in the entire cohort after chemotherapy, with a differential reduction in participants with a post therapy LVEF <55%. Pre-chemotherapy systolic strain was found to predict reduced E-Sr post therapy (P = 0.04). Univariate predictors of E-Sr were LVEF post therapy (P = 0.049) and systolic strain post-therapy (P = 0.01). In a multivariate analysis, systolic strain after chemotherapy was the strongest independent predictor (P = 0.001). CONCLUSION: Altered LV diastolic function was observed immediately after the administration of therapeutic doses of anthracycline chemotherapy. Furthermore, our analysis indicates that the changes in diastolic function are associated with reduced systolic function.

Gastrocnemius muscle contracture after spinal cord injury: a longitudinal study.

OBJECTIVE: The aim of this study was to examine changes in passive length and stiffness of the gastrocnemius muscle-tendon unit in people after spinal cord injury. DESIGN: In a prospective longitudinal study, eight wheelchair-dependent participants with severe paralysis were assessed 3 and 12 mos after spinal cord injury. Passive torque-angle data were obtained as the ankle was slowly rotated through range at six knee angles. Differences in passive ankle torque-angle data recorded at different knee angles were used to derive passive length-tension curves of the gastrocnemius muscle-tendon unit. Ultrasound imaging was used to determine fascicle and tendon contributions to the muscle-tendon unit length-tension curves. RESULTS: The participants had ankle contractures (mean [SD] maximum passive ankle dorsiflexion angle, 88 [9] degrees) 3 mos after spinal cord injury. Ankle range did not worsen significantly during the subsequent 9 mos (mean change, -5 degrees; 95% confidence interval, -16 to 6 degrees). There were no changes in the mean slack length or the stiffness of the gastrocnemius muscle-tendon unit or in the slack lengths of the fascicles or the tendon between 3 and 12 mos after spinal cord injury. There were no consistent patterns of the change in slack length or stiffness with the changes in ankle range in the data from the individual participants. CONCLUSIONS: This study, the first longitudinal study of muscle length and stiffness after spinal cord injury, showed that the length and the stiffness of the gastrocnemius did not change substantially between 3 and 12 mos after injury.

Mechanisms of increased passive compliance of hamstring muscle-tendon units after spinal cord injury.

BACKGROUND: People with spinal cord injury sometimes develop abnormally compliant hamstring muscle-tendon units. This study investigated whether the increased muscle-tendon compliance is due to a change in the passive properties of the muscle fascicles or tendons, or to muscle tears. METHODS: Semimembranosus muscle fascicle lengths were measured from ultrasound images obtained from 15 spinal cord injured subjects and 20 control subjects while the hip was passively flexed with the knee extended. Semimembranosus muscles of spinal cord injured subjects were inspected for tears using ultrasound imaging. FINDINGS: The mean (SD) hip angle at 30 Nm was 97 (SD 24) degrees in spinal cord injured subjects and 70 (SD 11) degrees in control subjects, indicating that spinal cord injured subjects had very compliant hamstring muscle-tendon units. The ratio of change in fascicle length to change in muscle-tendon length was not statistically different between spinal cord injured subjects and control subjects: muscle fascicles lengthened by 0.30 (SD 0.24) mm/mm in spinal cord injured subjects and 0.42 (SD 0.29) mm/mm in control subjects. These data were used to show that there was evidence of increased tendon compliance of spinal cord injured subjects compared to control subjects, but no evidence of increased muscle fascicle compliance. No tears were observed in semimembranosus muscles of spinal cord injured subjects. INTERPRETATION: The increased hamstring muscle-tendon compliance apparent in some spinal cord injured subjects is due, at least in part, to increased tendon compliance. There was no evidence that the increased muscle-tendon compliance was due to muscle tears.