早期下床活动对永久起搏器植入术后并发症影响的Meta分析

目的评价早期下床活动对永久起搏器植入术后并发症的影响。方法计算机检索Cochrane library、PubMed、EMBASE、Web of science、中国知网数据库、维普数据库、万方数据库等数据库中有关早期下床活动对永久起搏器植入术后并发症影响的临床对照试验,2名研究者按照纳入和排除标准选取文献,采用RevMan 5.3软件进行Meta分析。结果共纳入7篇文献,合计1 557例患者。Meta分析结果显示:被动电极起搏器植入术后3~24h下床活动对电极脱位、囊袋出血发生率差异均无统计学意义(P0.05);腰酸背痛、尿潴留、便秘发生率差异有统计学意义(P0.05)。结论被动电极起搏器植入术后早期下床活动不仅没有增加电极脱位、囊袋出血的风险,而且能降低腰酸背痛、尿潴留、便秘的发生率。     

Prevalence of scarred and dysfunctional myocardium in patients with heart failure of ischaemic origin: A cardiovascular magnetic resonance study

Background

Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) can provide unique data on the transmural extent of scar/viability. We assessed the prevalence of dysfunctional myocardium, including partial thickness scar, which could contribute to left ventricular contractile dysfunction in patients with heart failure and ischaemic heart disease who denied angina symptoms.

Methods

We invited patients with ischaemic heart disease and a left ventricular ejection fraction < 50% by echocardiography to have LGE CMR. Myocardial contractility and transmural extent of scar were assessed using a 17-segment model.

Results

The median age of the 193 patients enrolled was 70 (interquartile range: 63-76) years and 167 (87%) were men. Of 3281 myocardial segments assessed, 1759 (54%) were dysfunctional, of which 581 (33%) showed no scar, 623 (35%) had scar affecting ≤50% of wall thickness and 555 (32%) had scar affecting > 50% of wall thickness. Of 1522 segments with normal contractile function, only 98 (6%) had evidence of scar on CMR. Overall, 182 (94%) patients had ≥1 and 107 (55%) patients had ≥5 segments with contractile dysfunction that had no scar or ≤50% transmural scar suggesting viability.

Conclusions

In this cohort of patients with left ventricular systolic dysfunction and ischaemic heart disease, about half of all segments had contractile dysfunction but only one third of these had > 50% of the wall thickness affected by scar, suggesting that most dysfunctional segments could improve in response to an appropriate intervention.     

Safe performance of magnetic resonance imaging on a patient with an ICD

This is a report on a patient with an implanted cardioverter defibrillator (ICD) who intentionally underwent magnetic resonance imaging (MRI) of a malignant brain tumor. To avoid inadequate detection of ventricular tachycardia (VT) or ventricular fibrillation (VF), the ICD was inactivated by programming the VT-detection and VT/VF-therapy status off. The patient came through the protocol safely and without any difficulty or discomfort. There was no arrhythmic event. MRI affected neither programmed data nor the function of the ICD system.     

Strategies for the safe magnetic resonance imaging of pacemaker-dependent patients

OBJECTIVE: To determine if strategies used to safely scan nonpacemaker-dependent patients could be applied to facilitate safe MRI of pacemaker-dependent patients. INTERVENTIONS: Ten pacemaker-dependent patients underwent a total of 11 MRI scans of the head and neck. Screening, reprogramming VOO or DOO at 60 ppm, and monitoring strategies were used to facilitate MRI. A transmit-receive coil was used and MRI pulse sequences were modified to limit the whole-body specific absorption rate (SAR). RESULTS: All scans proceeded uneventfully. No difficulties in post-MRI telemetry or interrogation were seen and no post-MRI programming changes were noted. No patient experienced arrhythmia or symptoms during or immediately after MRI. Battery status remained unchanged. No patient experienced post-MRI change in sensing thresholds. Three patients showed no change in the atrial or ventricular pacing thresholds when the pre-MRI values were compared to the immediate post-MRI values and the 3-month follow-up values. All other patients showed a rise or fall of 0.5 V in their chamber threshold values when the pre-MRI, post-MRI, and 3-month follow-up values were compared. More patients showed a fall in their pacing thresholds than a rise post-MRI. CONCLUSION: While clearly a higher risk group, like nonpacemaker-dependent patients, MRI might be performed in pacemaker-dependent patients if appropriate pacemaker reprogramming, patient monitoring, and MRI scanning techniques are implemented.     

临床护理路径结合个案管理模式在永久性起搏器植入患者中的应用

目的：探讨临床护理路径结合个案管理模式在永久性起搏器植入患者中的应用效果。方法选择行永久性起搏器植入术的60例患者,随机分为观察组和对照组各30例。观察组患者实施临床护理路径结合个案管理模式,对照组接受传统护理模式。对比两组的住院天数、并发症发生例数、疾病知识问卷得分、患者满意度及焦虑水平。结果观察组与对照组相比,住院天数少,并发症例数少,疾病知识问卷得分高,患者满意度高,差异均有统计学意义(P<0.05);两组患者焦虑水平在入院时差异无统计学意义(P>0.05),出院时两组比较差异均有统计学意义(P<0.05)。结论在永久性起搏器植入患者中实施临床护理路径与个案管理相结合的模式,可以明显缩短住院天数,减少并发症,提高患者疾病知识掌握程度,提高患者满意度,减轻患者焦虑水平。     

Cardiac output and cardiac index measured with cardiovascular magnetic resonance in healthy subjects,elite athletes and patients with congestive heart failure

Background

Cardiovascular Magnetic Resonance (CMR) enables non-invasive quantification of cardiac output (CO) and thereby cardiac index (CI, CO indexed to body surface area). The aim of this study was to establish if CI decreases with age and compare the values to CI for athletes and for patients with congestive heart failure (CHF).

Methods

CI was measured in 144 healthy volunteers (39 ± 16 years, range 21–81 years, 68 females), in 60 athletes (29 ± 6 years, 30 females) and in 157 CHF patients with ejection fraction (EF) below 40% (60 ± 13 years, 33 females). CI was calculated using aortic flow by velocity-encoded CMR and is presented as mean ± SD. Flow was validated in vitro using a flow phantom and in 25 subjects with aorta and pulmonary flow measurements.

Results

There was a slight decrease of CI with age in healthy subjects (8 ml/min/m² per year, r² = 0.07, p = 0.001). CI in males (3.2 ± 0.5 l/min/m²) and females (3.1 ± 0.4 l/min/m²) did not differ (p = 0.64). The mean ± SD of CI in healthy subjects in the age range of 20–29 was 3.3 ± 0.4 l/min/m², in 30–39 years 3.3 ± 0.5 l/min/m², in 40–49 years 3.1 ± 0.5 l/min/m², 50–59 years 3.0 ± 0.4 l/min/m² and >60 years 3.0 ± 0.4 l/min/m². There was no difference in CI between athletes and age-controlled healthy subjects but HR was lower and indexed SV higher in athletes. CI in CHF patients (2.3 ± 0.6 l/min/m²) was lower compared to the healthy population (p < 0.001). There was a weak correlation between CI and EF in CHF patients (r² = 0.07, p < 0.001) but CI did not differ between patients with NYHA-classes I-II compared to III-IV (n = 97, p = 0.16) or patients with or without hospitalization in the previous year (n = 100, p = 0.72). In vitro phantom validation showed low bias (−0.8 ± 19.8 ml/s) and in vivo validation in 25 subjects also showed low bias (0.26 ± 0.61 l/min, QP/QS 1.04 ± 0.09) between pulmonary and aortic flow.

Conclusions

CI decreases in healthy subjects with age but does not differ between males and females. We found no difference in CI between athletes and healthy subjects at rest but CI was lower in patients with congestive heart failure. The presented values can be used as reference values for flow velocity mapping CMR.     

Long term effects of cocaine on the heart assessed by cardiovascular magnetic resonance at 3T

Background

Cocaine is an addictive, sympathomimetic drug with potentially lethal effects. The prevalence and features of cocaine cardiotoxicity are not well known. We aimed to assess these effects using a comprehensive cardiovascular magnetic resonance (CMR) protocol in a large group of asymptomatic cocaine users.

Methods

Consecutive (n = 94, 81 males, 36.6 ±7 years), non-selected, cocaine abusers were recruited and had a medical history, examination, ECG, blood test and CMR. The CMR study included measurement of left and right ventricular (LV, RV) dimensions and ejection fraction (EF), sequences for detection of myocardial oedema and late gadolinium enhancement (LGE). Images were compared to a cohort of healthy controls.

Results

Years of regular cocaine use were 13.9 ± 9. When compared to the age-matched healthy cohort, the cocaine abusers had increased LV end-systolic volume, LV mass index and RV end-systolic volume, with decreased LVEF and RVEF. No subject had myocardial oedema, but 30% had myocardial LGE indicating myocardial damage.

Conclusions

CMR detected cardiovascular disease in 71% of this cohort of consecutive asymptomatic cocaine abusers and mean duration of abuse was related to probability of LV systolic dysfunction.     

Guidelines and protocols for cardiovascular magnetic resonance in children and adults with congenital heart disease: SCMR expert consensus group on congenital heart disease

Cardiovascular magnetic resonance (CMR) has taken on an increasingly important role in the diagnostic evaluation and pre-procedural planning for patients with congenital heart disease. This article provides guidelines for the performance of CMR in children and adults with congenital heart disease. The first portion addresses preparation for the examination and safety issues, the second describes the primary techniques used in an examination, and the third provides disease-specific protocols. Variations in practice are highlighted and expert consensus recommendations are provided. Indications and appropriate use criteria for CMR examination are not specifically addressed.     

The role of cardiovascular magnetic resonance in the evaluation of patients with heart failure

Chronic heart failure is a common disorder placing significant burdens on patients and health-care services. Noninvasive imaging plays a central role in accurate diagnosis, determination of etiology and prognosis, and in monitoring therapy. Advances in technology mean cardiovascular magnetic resonance (CMR) imaging has established itself as both a valuable clinical and research tool in this arena. Not only is CMR the new gold standard for accurate and reproducible assessment of ventricular volumes and mass, but by using gadolinium contrast, underlying pathology can often be determined. In ischemic cardiomyopathy a 'one stop' assessment can be made of function, perfusion and mass. Continuing advances such as myocardial tagging and the increasing availability of CMR mean that it will become an increasingly important and useful tool for clinicians looking after patients with cardiomyopathy and heart failure.     

Migration of an abandoned pacemaker generator into the pouch of Douglas in a child with complex congenital heart disease

A young girl with complex congenital heart disease underwent Fontan procedure and multiple pacemaker revisions, including abandonment of an intraabdominal pacemaker generator at age eight. She presented two years later with constipation and abdominal twitching. Radiographs, pacemaker interrogation, and laparoscopy confirmed dislocation of the abandoned generator and intraperitoneal migration into the pouch of Douglas. The device was removed surgically without incident.     

Magnetic resonance of the heart in a muscular dystrophy patient with an MR conditional ICD: Assessment of safety,diagnostic value and technical limitations

Cardiovascular magnetic resonance (CMR) studies in patients with pacemakers or implantable cardioverter/defibrillators (ICD) are increasingly required in daily clinical practice. Therefore, in the last years the manufacturers developed not only MR-conditional pacemakers, but also MR-conditional ICDs. However, the clinical experience regarding the feasibility and limitations of MR studies of the heart in patients with ICDs is still limited. In particular, there are hardly any CMR studies in the same patients performed prior to and post ICD implantation allowing a one-to-one comparison of the obtained CMR images. This is the first presentation of a CMR study in a patient with the world’s first and so far only MR-conditional ICD. In our case, a major problem related to the presence of the MR conditional ICD was an image artifact caused by the device’s generator which hampered the visualization of the midventricular and apical anterior and antero-lateral segments in all sequences performed. Considering previous studies, right chest implantation of the ICD could probably have helped in this setting and may be preferred in future ICD implantations. Our case report nicely illustrates the real clinical need for specially designed implantable devices that ensure safe and high-quality imaging in patients in whom serial CMR is required.     

Mapping iron in human heart tissue with synchrotron x-ray fluorescence microscopy and cardiovascular magnetic resonance

Background

MRI assessment of cardiac iron is particularly important for assessing transfusion-dependent anaemia patients. However, comparing the iron distribution from histology or bulk samples to MRI is not ideal. Non-destructive, high-resolution imaging of post-mortem samples offers the ability to examine iron distributions across large samples at resolutions closer to those used in MRI. The aim of this ex vivo case study was to compare synchrotron X-ray fluorescence microscopy (XFM) elemental iron maps with magnetic resonance transverse relaxation rate maps of cardiac tissue samples from an iron-loaded patient.

Methods

Two 5 mm thick slices of formalin fixed cardiac tissue from a Diamond Blackfan anaemia patient were imaged in a 1.5 T MR scanner. R₂ and R_2* transverse relaxation rate maps were generated for both slices using RF pulse recalled spin echo and gradient echo acquisition sequences. The tissue samples were then imaged at the Australian Synchrotron on the X-ray Fluorescence Microscopy beamline using a focussed incident X-ray beam of 18.74 keV and the Maia 384 detector. The event data were analyzed to produce elemental iron maps (uncalibrated) at 25 to 60 microns image resolution.

Results

The R₂ and R_2* maps and profiles for both samples showed very similar macro-scale spatial patterns compared to the XFM iron distribution. Iron appeared to preferentially load into the lateral epicardium wall and there was a strong gradient of decreasing iron, R₂ and R_2* from the epicardium to the endocardium in the lateral wall of the left ventricle and to a lesser extent in the septum. On co-registered images XFM iron was more strongly correlated to R_2* (r = 0.86) than R₂ (r = 0.79). There was a strong linear relationship between R_2* and R₂ (r = 0.87).

Conclusions

The close qualitative and quantitative agreement between the synchrotron XFM iron maps and MR relaxometry maps indicates that iron is a significant determinant of R₂ and R_2* in these ex vivo samples. The R₂ and R_2* maps of human heart tissue give information on the spatial distribution of tissue iron deposits.

Electronic supplementary material

The online version of this article (doi:10.1186/s12968-014-0080-2) contains supplementary material, which is available to authorized users.     

相位对比磁共振成像诊断小儿继发孔型房间隔缺损

目的 探讨相位对比磁共振成像(PC-MRI)在诊断小儿继发孔型房间隔缺损(ASD)中的应用价值. 方法 42例经胸超声心动图证实为继发孔型ASD患儿,年龄9个月～15岁.采用PC-MRI采集通过ASD的左向右分流束的图像,以及缺损边缘与上下腔静脉及二尖瓣、右上肺静脉连线的PC-MRI图像. 结果 42例PC-MRI测量的ASD直径、缺损边缘与上腔静脉、下腔静脉、房室瓣及右上肺静脉间的距离均与经胸超声心动图的结果有很好的相关性(P<0.001).26例PC-MRI测量结果与外科手术结果高度相关(P<0.001),不同流速编码中,流速编码50～70 cm/s时PC-MRI测量到的缺损直径与外科手术结果相对最为一致. 结论 PC-MRI可直观显示房间隔缺损的位置、数目、大小和与周围心内结构的空间关系,同时可进行准确的定量分析, 为心脏解剖畸形诊断提供了一种新的检测方法和思路.     

脑白质疏松症患者静息态功能磁共振成像的初步研究

目的应用静息态血氧水平依赖功能磁共振成像(blood oxygenation level dependent-functional MRI,BOLD-fMRI)技术探测脑白质疏松症(leukoaraiosis, LA)患者脑神经元自发活动情况。材料与方法19例轻度LA患者(轻度LA组)、21例重度LA患者(重度LA组)和19例年龄性别相匹配的健康志愿者(正常对照组)行fMRI扫描,并计算获取低频振幅(ALFF)图进行统计学分析。结果与轻度组比较,重度组患者在左侧楔前叶、右侧角回ALFF值下降(校正后P＜0.05);与正常组相比较,重度组患者在左侧楔前叶、右侧角回、右侧额中回ALFF值下降(校正后P＜0.05)。结论 LA患者静息状态下存在局部神经元自发活动异常。     

A prospective multicenter study on the safety of a pacemaker with automatic energy control: influence of the electrical factor on chronic stimulation threshold. PEACE Investigators

The effectiveness and safety of a pacemaker with automatic control of capture was evaluated in 162 patients followed at 27 Spanish centers. The aim of our prospective, multicenter, and randomized trial was to determine the relationship between the voltage output of the pulse generator and the stimulation threshold. We randomized 162 patients (107 men, mean age 75 +/- 12 years). We implanted a ventricular pacemaker model Regency SR+ or SC+ with Pacesetter's low polarization bipolar leads Membrane E 1450. The patients were randomized to receive Autocapture or not; group I (81 patients) Autocapture On, pulse output automatically adjusted and group II (81 patients) Autocapture Off, fixed output parameters (3.9 V, 0.37 ms). We performed a 6-month follow-up measuring stimulation threshold by means of the VARIO test and Autocapture test, evoked response signal, and R wave signal. The mean R wave was 15.77 +/- 3.5 mV at the end of the follow-up for group I, and 14.91 +/- 6.8 mV for group II (P = NS). The measured evoked response at the end of the follow-up was 9.25 mV in Group I and 8.48 mV in Group II (P = NS). The stimulation threshold was not different between groups. The current density created with the voltage and pulse width used in this study (< or = 3.9 V and 0.37 ms) at the tip of this electrode during the maturation process had no influence on the development of the chronic detection and stimulation thresholds.     

心脏磁共振成像预测酒精性心肌病心力衰竭患者心脏不良事件

目的 探讨心脏磁共振（CMR）心肌对比剂延迟强化（LGE）对酒精性心肌病（ACM）心力衰竭患者心脏不良事件的预测能力。方法 纳入临床诊断为ACM并出现心力衰竭症状的患者58例,对所有患者行CMR,根据是否出现LGE将患者分为LGE（+）组和LGE（-）组。对所有患者进行随访,随访终点定义为发生心脏不良事件,对两组患者随访期间出现的心脏不良事件进行生存分析;将LGE、左心室舒张末期容积、左心室收缩末期容积、左心室射血分数、左心室心肌质量指数、心力衰竭出现时间、饮酒时间纳入多因素Cox比例风险模型,分析心脏不良事件的预测因子。结果 LGE（+）组22例,LGE（-）组36例,共10例发生心脏不良事件,LGE（+）组发生率[31.82%(7/22)]显著高于LGE（-）组[8.33%(3/36),P=0.02]。LGE是心脏不良事件的强预测因子（风险比值：5.74, P=0.02）。结论 CMR心肌LGE是出现心力衰竭症状的ACM患者不良心脏事件的强预测因子。     

Benign endometrial adenofibroma and polyp in patients receiving tamoxifen: findings on transvaginal ultrasonography and magnetic resonance imaging

Tamoxifen, a selective estrogen receptor modulator, is widely used to treat breast cancer, but an association has been reported between tamoxifen and the development of endometrial lesions, including endometrial carcinoma, endometrial polyps, and endometrial hyperplasia. There have also recently been a few reports on the relation between tamoxifen and adenofibroma. We present two case reports, one of a patient with a uterine adenofibroma and one of a patient with an endometrial polyp, both of whom received tamoxifen. Cases 1 and 2 are 75- and 65-year-old postmenopausal women, respectively, undergoing tamoxifen therapy. In both cases, endometrial thickening and many small cysts in the uterine cavity were revealed by transvaginal ultrasonography or magnetic resonance imaging. Postoperative microscopic examination confirmed the mass as an adenofibroma in case 1 and as an endometrial polyp in case 2.     

Multiparametric cardiovascular magnetic resonance surveillance of acute cardiac allograft rejection and characterisation of transplantation-associated myocardial injury: a pilot study

Background

Serial surveillance endomyocardial biopsies are performed in patients who have recently undergone heart transplantation in order to detect acute cardiac allograft rejection (ACAR) before symptoms occur, however the biopsy process is associated with a number of limitations. This study aimed to prospectively and longitudinally evaluate the performance of multiparametric cardiovascular magnetic resonance (CMR) for detecting and monitoring ACAR in the early phase post-transplant, and characterize graft recovery following transplantation.

Methods

All patients receiving a heart transplant at a single UK centre over a period of 25 months were approached within one month of transplantation. Multiparametric CMR was prospectively performed on the same day as biopsy on four separate occasions (6 weeks, 10 weeks, 15 weeks and 20 weeks post-transplant). CMR included assessment of global and regional ventricular function, myocardial tissue characterization (T1 mapping, T2 mapping, extracellular volume, LGE) and pixel-wise absolute myocardial blood flow quantification. CMR parameters were compared with biopsy findings. As is standard, grade 2R or higher ACAR was considered significant.

Results

88 CMR-matched biopsies were performed in 22 patients. Eight (9%) biopsies in 5 patients demonstrated significant ACAR. Significant ACAR was associated with a reduction in circumferential strain (−12.7 ± 2.5% vs. -13.7 ± 3.6%, p = 0.047) but there was considerable overlap between groups. Whilst trends were observed between ACAR and proposed CMR markers of oedema, particularly after adjusting for primary graft dysfunction, differences were not significant. Significant improvements were seen in markers of graft structure and contractility, oedema and microvascular function over the period studied, although few parameters normalised.

Conclusions

This study provides novel insight into the myocardial injury associated with transplantation, and its recovery, however multiparametric CMR was not able to accurately detect ACAR during the early phase post-transplantation.