Age-Related Ultrasound Changes in Muscle Quantity and Quality in Women

This study investigated the age-related changes in muscle quantity and quality in the trunk and limbs of women. A total of 128 females were divided into four age groups: young, middle-aged, young-old and old-old. Muscle thickness (MT) and echo intensity (EI) of the biceps brachii, quadriceps femoris, rectus abdominis, external oblique, internal oblique and transversus abdominis were measured using B-mode ultrasonography. The EIs of the biceps brachii, quadriceps femoris and transversus abdominis were significantly higher in the middle-aged group than in the young group; however, there were no significant differences in MT. Compared with the young group, all other groups had significant changes in both MT and EI of the rectus abdominis, external oblique and internal oblique muscles. Thus, qualitative changes in muscle may occur earlier than quantitative changes, and loss of muscle mass may occur earlier in the superficial abdominal muscles than in the other muscles.     

2型糖尿病患者骨骼肌厚度和弹性变化及其影响因素

目的 观察2型糖尿病患者骨骼肌厚度和弹性变化及其影响因素。方法 前瞻性招募62例2型糖尿病患者（T2DM组）及60名健康成年人（HC组）,以剪切波弹性成像（SWE）技术检测其放松及收缩状态下腹直肌和腓肠肌最大杨氏模量（E_max）,比较组间2种状态下骨骼肌厚度及弹性模量,并采用多重线性回归分析影响腹直肌和腓肠肌弹性模量的因素。结果 组间放松及收缩状态下腹直肌和腓肠肌厚度差异均无统计学意义（P均>0.05）;T2DM组放松及收缩状态下腹直肌及腓肠肌E_max均低于HC组（P均<0.05）。多重线性回归分析显示,T2DM组放松及收缩状态下腹直肌及腓肠肌弹性模量均随病程、空腹血糖（FBG）及糖化血红蛋白（HbA1c）而呈线性降低（P均<0.05）。结论 2型糖尿病患者骨骼肌弹性模量降低,且随病程、FBG及HbA1c而呈线性下降。     

盆底神经肌肉电刺激和悬吊训练治疗产后腹直肌分离的效果

目的 观察盆底神经肌肉电刺激(NMES)结合悬吊训练(SET)对产后腹直肌分离的临床疗效。方法 2019年9月至12月,产后腹直肌分离> 2 cm、盆底肌肌力Ⅲ级以上患者90例,随机分为三组,分别接受单纯盆底NMES (A组)、NMES结合SET (B组)和单纯SET (C组)治疗,共4周。治疗前、治疗2周、治疗4周、治疗结束后4周,测量腹直肌分离距离。结果 治疗后,各组腹直肌分离距离均明显缩小(F > 8.327, P < 0.01);治疗后各时间点,B组腹直肌分离距离最小( F > 8.327, P < 0.01);多重比较,A组与C组无显著性差异( P > 0.05)。 结论 盆底NMES和SET均可有效改善产后腹直肌分离,两种方法结合疗效更佳。     

Free rectus abdominis muscle flap: advantages in lower extremity reconstruction

Major soft tissue losses of the distal portion of the leg usually require free tissue transfer for reconstruction. We have recently treated seven patients with free rectus abdominis muscle flaps. The rectus abdominis has several advantages over other muscles; these advantages simplify such reconstructions. Elevation of this muscle can be done simultaneously with recipient vessel dissection without the need for patient repositioning. The deep inferior epigastric vessels provide a reliable pedicle of one large artery and two veins of sufficient length to accomplish microvascular anastomosis outside the zone of injury without the use of vein grafts. The size and shape of the muscle conforms well to the defects of many wounds in the leg. There is no functional deficiency from the use of one muscle, and the donor site scar is relatively inconspicuous since the rectus abdominis is harvested through a midline abdominal incision. There have been two complications in this series, one intraoperative flap failure, and one case of recurrent osteomyelitis. There has been no donor site morbidity. We recommend the free rectus abdominis muscle flap for the reconstruction of many complex wounds of the distal portion of the leg.     

Clinical Experience with a New Software-Based Antitachycardia Pacemaker for Recurrent Supraventricular and Ventricular Tachycardias

The Intermedics Intertach 262-12 tachycardia reversion pulse generator was implanted in 14 patients (six male, eight female, mean age at implantation 45 +/- 16 years) with recurrent symptomatic tachycardias. Six patients had atrioventricular (AV) nodal reentrant tachycardia, three patients had orthodromic tachycardia with Wolff-Parkinson-White syndrome, two had circus movement tachycardia via a concealed bypass tract, two had ventricular tachycardia, one patient had atrial flutter. Mean duration of symptoms before implantation was 8 +/- 4 years and mean number of antiarrhythmic drug trials was 3.5 +/- 1. The primary tachycardia response made consisted of autodecremental pacing in one patient, burst pacing in two patients, and adaptive scanning of the initial delay or burst cycle length in eleven patients. The secondary tachycardia response mode consisted of autodecremental pacing in four patients, burst pacing in three patients and burst scanning in four patients. Tachycardia response was automatic in all but one patient with ventricular tachycardia. During a follow-up period of 30.5 +/- 10.6 months, one patient with ventricular tachycardia died from a nonarrhythmic cause. Reinterventions were necessary due to electrode fracture in one patient and due to pacemaker software defect in another one. Two patients underwent surgical cure of their arrhythmia: one patient with atrial flutter and one patient with AV nodal reentry tachycardia, 24 months and 11 months postpacemaker implantation, respectively. Four patients required digitalis to prevent pacing induced atrial fibrillation. Other proarrhythmic effects were not encountered. The pacemaker proved to be a versatile system with reliable tachycardia detection and termination functions. It provided a valuable adjunctive therapy in these selected patients.     

The effects of aquatic trunk exercise on gait and muscle activity in stroke patients: a randomized controlled pilot study

[Purpose] The purpose of this study was to investigate the relationship between muscle activity and gait function following aquatic trunk exercise in hemiplegic stroke patients. [Subjects and Methods] This study’s participants included thirteen hemiplegic patients (ten males and three females). The aquatic therapy consisted of administering concentrative aquatic therapy for four weeks in a therapeutic pool. Gait parameters were measured using a gait analysis system adjusted to each subject’s comfortable walking speed. Electromyographic signals were measured for the rectus abdominis, external abdominal oblique, transversus abdominis/internal-abdominal oblique, and erector spine of each patients. [Results] The pre- and post-training performances of the transversus abdominis/internal-abdominal oblique were compared statistically. There was no statistical difference between the patients’ pre- and post-training values of maximal voluntary isometric contraction of the rectus abdominis, but the external abdominal oblique values tended to improve. Furthermore, gait factors improved significantly in terms of walking speeds, walking cycles, affected-side stance phases, affected-stride lengths, and stance-phase symmetry indices, respectively. [Conclusion] These results suggest that the trunk exercise during aquatic therapy may in part contribute to clinically relevant improvements in muscle activities and gait parameters.Key words: Aquatic trunk exercise, Gait, Muscle activity     

Bradycardia and Syncope in Children Not Controlled by Pacing: Beta-Adrenergic Hypersensitivity

Cardiac pacing is frequently employed in the therapy of children with syncope and documented bradycardia. This report describes two children, ages 7 and 9 years, who underwent placement of demand ventricular pacing systems for documented bradycardia and syncope. Cardiac catheterization and intracardiac electrophysiological studies failed to show evidence of structural abnormalities, sinus node or conduction system disease, inducible arrhythmias, or VA conduction in each patient. Both patients had persistent symptoms after pacemaker implantation. Autonomic function testing with continuous heart rate and blood pressure monitoring revealed exaggerated beta-adrenergic responses to simple standing and small doses of isoproterenol. Symptoms were completely eliminated with atenolol. In these two children, cardiac pacing alone was not adequate for relief of symptoms. Autonomic mechanisms of bradycardia and hypotension should be considered prior to implantation of permanent pacing systems in children.     

Hemodynamic and symptomatic consequences of ventricular pacing

After implantation of a ventricular demand pacemaker (VVI), occasional patients continue to have dizziness, syncope, or near syncope ("pacemaker syndrome"). To identify patients in whom VVI pacing may have deleterious effects, we compared cuff blood pressure responses to VVI pacing with blood pressure responses to atrioventricular sequential pacing (DVI) or sinus rhythm in 50 consecutive patients. Patients with intact ventriculoatrial conduction had a much greater decrease in systolic blood pressure with VVI pacing (24 +/- 11 mm Hg) than those with ventriculoatrial dissociation (-4 +/- 15 mm Hg) (P less than 0.005). Patients who were in heart failure had a lesser decrease in blood pressure with VVI pacing than did those without failure (P less than 0.05); 13 of the 14 heart failure patients lacked ventriculoatrial conduction. Ten patients had symptomatic dizziness after VVI pacing; the incidence of symptoms was higher in patients with ventriculoatrial conduction (9 of 23) than in those without ventriculoatrial conduction (1 of 27) (P less than 0.003). We conclude that the presence of intact ventriculoatrial conduction appears to be a crucial determinant of the hemodynamic response to VVI pacing, and its presence may identify patients who are at risk for "pacemaker syndrome."     

Quantification of the differences in electromyographic activity magnitude between the upper and lower portions of the rectus abdominis muscle during selected trunk exercises

BACKGROUND AND PURPOSE: Controversy exists around exercises and clinical tests that attempt to differentially activate the upper or lower portions of the rectus abdominis muscle. The purpose of this study was to assess the activation of the upper and lower portions of the rectus abdominis muscle during a variety of abdominal muscle contractions. SUBJECTS: Subjects (N = 11) were selected from a university population for athletic ability and low subcutaneous fat to optimize electromyographic (EMG) signal collection. METHODS: Controlling for spine curvature, range of motion, and posture (and, therefore, muscle length), EMG activity of the external oblique muscle and upper and lower portions of rectus abdominis muscle was measured during the isometric portion of curl-ups, abdominal muscle lifts, leg raises, and restricted or attempted leg raises and curl-ups. A one-way repeated-measures analysis of variance was used to test for differences in activity between exercises in the external oblique and rectus abdominis muscles as well as between the portions of the rectus abdominis muscle. RESULTS: No differences in muscle activity were found between the upper and lower portions of the rectus abdominis muscle within and between exercises. External oblique muscle activity, however, showed differences between exercises. DISCUSSION AND CONCLUSION: Normalizing the EMG signal led the authors to believe that the differences between the portions of the rectus abdominis muscle are small and may lack clinical or therapeutic relevance.     

Noninvasive conversion of a fixed-rate demand pacemaker to activity mode: a method for assessing the clinical effect of rate-responsiveness

Some patients with fixed-rate demand pacemakers may benefit from conversion to a rate-responsive pacing system. In this report, we describe a technique by which the effect of rate-responsive pacing can be assessed before replacing the pacemaker system. An externally positioned activity-mode physiologic pulse generator was used to drive a previously implanted ventricular demand pacemaker programmed to the triggered mode. Comparison of exercise capacity under both conditions suggested a substantial benefit from rate-responsiveness.     

Long-Term Reliability of Single Lead Atrial Synchronous Pacing Systems Using Closely Spaced Atrial Dipoles: Five-Year Experience

To assess the long-term capability of single atrioven ticular (AV) lead VDD pacing systems using close atrial dipoles to assure reliable atrial guided pacing, the safety and efficacy of 86 VDD units implanted in 73 patients at a single center since November 1988 was reviewed. All patients suffered from advanced AV block with normal sinoatrial function. Sixty five patients received a LEM/CCS Twinal 30/30S system, four patients received a Vitatron-Saphir system, and four patients received a Medtronic Thera VDR 8348 system. All patients underwent provocative tests in search of myopotential interference, and Holter recordings; in a group of patients who underwent pacemaker replacement a comparison was made between implant and replacement measurements. The mean follow-up duration was 27.3 months. A high percentage of successfully VDD paced patients and a low incidence of pacemaker malfunction, regularly solved by pacemaker reprogramming, was reported. Atrial signal amplitudes comparable to those measured at implant were found at replacement in all patients. These data support the long-term reliability of single AV lead VDD pacing systems with closely spaced atrial dipoles, as well as stable atrial sensing by floating bipolar atrial electrodes and effective atrial synchronous ventricular pacing over time.     

Rate Control with an External SO2 Closed Loop System

In 20 volunteers (mean age 35.5 y) and 12 pacemaker patients (mean age 68.7 y), central venous oxygen saturation (SO₂) was monitored continuously by means of an optical sensor integrated in an external transvenous pacing lead placed in the right ventricular cavity. From the SO₂ signal recorded at rest and during various modalities of exercise, an algorithm for controlling pacing rate of an external pacing system was developed. An open loop system was used in the volunteers, allowing the comparison of the computed pacing rate with the individual intrinsic heart rate. There was an excellent correlation between the two frequencies as far as the dynamic characteristics and the steady state relationship were concerned. In five pacemaker patients who were stimulated via the external lead, a closed loop control of pacing rate was used. In one patient with a DDD pacemaker implanted for third degree AV-block, the rate response of the SO₂ driven pacemaker was well in accordance with the rate attained with the implanted atrial triggered system. With both pacing modes, exercise capacity as determined on a symptom limited treodmill test was identical. In four patients (3 AV block III, 1 bradyarrhythmia) an improvement in exercise tolerance up to 65 percent could be demonstrated with the rate responsive pacing mode. In all patients, it could he shown that an autoregulating pacemaker system with SO₂ is an open possibility.     

Muscle activities of the rectus abdominis and rectus femoris and their ratio during leg raises performed by healthy adults

[Purpose] The purpose of this study was to analyze muscle activation during hip flexion in the supine position to examine the activation characteristics of the rectus abdominis and rectus femoris. [Subjects] The subjects of this study were 20 healthy adults (10 males and 10 females). [Methods] Muscle activities of the rectus abdominis and rectus femoris while raising the leg from 0°–60° were measured in 15-degree divisions and their ratio was calculated. [Results] Statistically significant differences were found in the muscle activities of the rectus femoris and rectus abdominis were found among each division of during hip flexion in the supine position. The rectus abdominis and rectus femoris ratios increased as the angle of hip flexion increased. [Conclusion] During hip flexion from 0°–45° in the supine position, femur motion caused hip flexion. At angles greater than or equal to 45° hip flexion was accompanied by pelvic motion.Key words: Hip flexion, Leg raise, Muscle activities     

An operative case of inferior vena cava stenosis due to fibrosis around permanent pacemaker leads

A 56-year-old woman presented with general fatigue, dyspnea on exercise, and hepatomegaly subsequent to secondary implantation of a pacemaker. On admission, cardiac echo examination showed tricuspid valve regurgitation due to a migrated looped lead. At surgery, there was evidence of severe stenosis at both orifices of the superior and inferior vena cavae due to fibrous tissue around the leads. We removed the fibrous tissue, pacing leads, and generator. New leads were anchored onto the epicardium and a generator was inserted under the rectus muscle. The postoperative course was satisfactory and the symptoms disappeared.     

Safe Performance of Magnetic Resonance Imaging on Five Patients with Permanent Cardiac Pacemakers

Five patients with permanent cardiar pacemakers (Pacesetter models 261. 283. 2020, 2022) underwent magnetic resonance imaging (MRI). Only one patient (underlying rhythm asystole) was pacemaker dependent. A variety of pacing configuration (single and dual chamber: unipolar and bipolar: sensor and nonsensor driven) were scanned. A thorough evaluation of each pacing system was performed before and after scanning including determination of pacing and sensing thresholds. During MRI the patient was monitored using either ECG, pulse oximetry, or direct voice contact. In four patients heavy dressings were applied over the pacemaker pocket site. Patients were asked to report any symptoms experienced during MRI. Results: The four nonpacemaker dependent patients remained in sinus rhythm throughout the MRI. During and after the MRI all pacemakers continued to function normally except for one transient pause of approximately 2 seconds (noted by pulse oximeter) toward the end of the scan. This occurred in pacemaker dependent patient with a unipolar dual chamber device programmed DOO. No patient experienced any lorque or heat sensation. Conclusion: When appropriate strategies are used our experience suggests that MRI may be performed when necessary with an acceptable risk-benefit ratio to the patient. It is unclear whether the isolated pause that was observed was due to the effect of the MRI, an artifact with the monitoring system, or oversensing by the pacemaker. Appropriable patient selection, close monitoring during the scan, and follow-up after MRI are of paramount importance. Further stydy is necessary to refine the appropriate stralegies that could be used to consistently perform MRI sately in a selected pacemaker population.     

Atrioventricular and Ventriculo-Atrial Conduction in Patients with Symptomatic Sinus Node Dysfunction

In 14 patients with symptomatic sinus node dysfunction—sinus bradycardia, sino-atrial exit block, or sinus arrest—electrophysiological studies were performed before implantation of a pacemaker. In 8 patients incremented high right atrial pacing showed AV-nodal Wenckebach at pacing rates equal to or above 130/min (group I); in 6 patients AV-nodal Wenckebach was reached at pacing rates Jess than 130/min (group II). During ventricular pacing at a rate 10–15% faster than the existing sinus rate, ventriculo-atrial (VA) conduction was present in all patients of group I, while VA conduction was present in only 2 patients of group II (p < 0.05). Patients with symptomatic sinus node dysfunction but with intact AV conduction frequency show VA conduction during ventricular pacing and thus are particularly at risk for developing a pacemaker syndrome when a ventricular demand (VVI) pacemaker is implanted. This complication can be avoided by atrial demand (AAI) pacing or A V sequential (DVI) pacing. When adequate experience has been gathered with A V universel (DDD) pacemakers, the indications for selection of a pacemaker in patients with symptomatic sinus node dysfunction will probably change.     

Effects of bridge exercise on trunk core muscle activity with respect to sling height and hip joint abduction and adduction

[Purpose] This study evaluated the effects of bridge exercise on trunk core muscle activity with respect to sling height and hip joint abduction and adduction. [Subjects] Fifteen healthy adult males participated. [Methods] In the bridge exercise, the height of the sling was set low or high during hip joint abduction and adduction. Electromyography was used to compare the differences between the muscle activities of the transverse abdominis, rectus abdominis, and erector spinae muscles. [Results] The muscle activities of the transverse abdominis, rectus abdominis, and erector spinae were significantly higher in the high sling position. Furthermore, the activities of the transverse abdominis and erector spinae were significantly higher during hip joint adduction than abduction regardless of sling height. [Conclusion] A high sling height is the most effective intervention for increasing the muscle activities of the transverse abdominis and erector spinae muscles during hip joint adduction in a bridge exercise.Key words: Bridge exercise, Trunk core muscle, Sling     

Adverse Pacemaker Hemodynamics Evaluated by Pulmonary Venous Flow Monitoring

The pacemaker syndrome refers to symptoms and signs in the pacemaker patient caused by an inadequate timing of atrial and ventricular contractions. The lack of normal atrioventricular synchrony may result in a decreased cardiac output and venous cannon A waves. The objective of this study was to define the left atrial and pulmonary venous flow response to ventricular pacing in a group of 14 unselected consecutive patients with total heart block and sinus rhythm. Pulmonary venous flow was assessed by transesophageal pulsed Doppier echocardiography in the VVI and ODD pacing modes. An inappropriate atrial timing caused a marked augmentation of the normally small pulmonary venous z wave in all patients ("negative atrial kick" peak z wave in DDD pacing 14.5 ± 4.6 cm/s, VVI pacing 51.8 ± 15.0 cm/s). Restoration of AV synchrony (DDD pacing, AV interval 100 ms) abolished these "cannon z waves" in all patients, and a normal pattern of pulmonary venous flow was achieved. Abnormal pulmonary venous flow characteristics were observed in 2 of 14 patients during DDD pacing with short AV intervals (100 ms). The Doppier pattern was similar to the findings seen in VVI pacing. Assessment of pulmonary venous flow by transesophageal pulsed Doppier echocardiography may provide a simple, sensitive, and relatively noninvasive technique to evaluate patients with suspected pacing induced adverse hemodynamics.     

Muscle mass and composition of the hip, thigh and abdominal muscles in women with and without hip osteoarthritis

The objective of this study was to compare muscle mass and composition between individuals with and without hip osteoarthritis. Twenty-four women with hip osteoarthritis (OA group) and 16 healthy women (healthy group) participated in this study. Muscle thickness (MT) and echo intensity (EI) were measured as indices of muscle mass and composition, respectively, using ultrasound imaging. Seven muscles were examined: gluteus maximus, gluteus medius, quadriceps femoris, rectus abdominis, external oblique, internal oblique and transversus abdominis. MT of only quadriceps femoris in the OA group was significantly thinner than that in the healthy group. EIs of gluteus medius, quadriceps femoris and rectus abdominis were significantly higher in the OA group than those in the healthy group. Thus, actual contractile tissue of gluteus medius and rectus abdominis substantially decreased, although muscle mass was similar, whereas both quantitative and qualitative changes occurred in quadriceps femoris in patients with hip OA.     

Ventricular Pacing as the Preferable Mode for Long-Term Pacing in Patients with Carotid Sinus Syncope of the Cardioinhibitory Type

This study was designed to determine the efficacy of long-term VVI pacing in patients having the isolated cardioinhibitory type of carotid sinus syncope. The study included 20 patients suffering from repeated syncopal attacks; all were proven by electrophysiological studies to have isolated forms of cardioinhibitory type carotid sinus syncope. Long-term pacing by the VVI mode was carried out in all patients by programming the pacemaker rate well below the patient's sinus rate. The follow-up period after pacemaker implantation, which ranged from 2 to 54 months (average, 20 months), revealed that none of the patients had any recurrence of syncopal attack. Repeated Holter monitoring showed that ten had permanent sinus rhythm without any artificial pacing activity, while in the other ten, pacemaker activity was recorded--predominant in two patients and rare in the other eight. During Holter monitoring, attacks of weakness were reported by four patients; however, they were not related to pacemaker activity. This report indicates the importance of electrophysiological studies in patients suffering from carotid sinus syncope. These studies make possible the diagnosis of the isolated form of cardioinhibitory type syncope for which VVI pacing offers complete relief of symptomatology, thus rendering AV sequential pacing superfluous.