高血压性脑出血急性期脑灌注显像的研究

目的　研究高血压性脑出血 (HCH)急性期 (72h内 )血肿周围及远隔区域的脑血流量 (rCBF)变化。方法　对30例HCH患者行发病后 2 4h内CT显像及发病后 72h内脑灌注显像 (SPECT) ,计算出血量及水肿量 ,对rCBF进行半定量分析 ,并进行 72h内临床和SPECT评分及发病后第 4周的日常生活能力评分 (BI)。结果　 (1)脑水肿在脑出血后 2 4h内产生 ,并且早期水肿程度与出血量及血流灌注缺损容积 (FDV)呈显著相关 (r分别为 0 .86 85和 0 .35 6 2 ,P <0 .0 1)。 (2 )脑出血后血肿周边及双侧大脑半球血流量均显著降低。 (3)急性期SPECT总评分与相应的临床功能缺损评分呈直线相关 (r=0 .87,P <0 .0 1) ,与 4周时的BI呈直线负相关 (r=- 0 .82 ,P <0 .0 1)。结论　(1)脑水肿在脑出血后 2 4h内产生 ;(2 )rCBF与出血量及出血部位有关 ;(3)脑出血急性期血肿周边也存在着缺血半暗带。     

Mechanisms of right atrial tachycardia occurring late after surgical closure of atrial septal defects

Postatriotomy atrial tachycardia ablation. INTRODUCTION: In patients without structural heart disease, the most frequently occurring AT is the common atrial flutter. In patients with repaired congenital heart disease other mechanisms of AT may occur, due to the presence of an atriotomy that can provide a substrate for reentry. The aim of the present study was to identify the mechanisms of atrial tachycardia (AT) occurring late after atrial septum defect (ASD) repair, with the help of a three-dimensional electroanatomical mapping system. METHODS AND RESULTS: Twenty-two consecutive patients presenting with AT underwent complete electroanatomic mapping (CARTO, Biosense Webster, Diamond Bar, CA) of spontaneously occurring and inducible right ATs. Complete maps of 26 ATs were obtained. Three tachycardia mechanisms were identified: single-loop macroreentrant atrial tachycardia (MAT) (n=7), double-loop MAT (n=18), and focal AT (n=1). In all MATs, protected isthmuses were identified as the electrophysiological substrate of the arrhythmia, most frequently the cavotricuspid isthmus (CTI) (n=24), and a gap between the inferior vena cava and a line of double potentials (n=11). A mean number of 13.5+/-2.1 radiofrequency applications were delivered to transect these critical parts of the circuit. During a follow-up of 25+/-16 months the RF ablation was acutely successful in all patients. Thirteen patients (59%) had an early recurrence of MAT and needed an additional ablation procedure. One of those patients needed two additional ablation procedures. CONCLUSIONS: Three-dimensional electroanatomic mapping is useful to identify postsurgical AT mechanisms; the CTI isthmus is involved in 92% MAT, and if the right atrial free wall (RAFW) abnormal tissue related to surgical scar is present this substrate contributes to the MAT circuit.     

Validation of computed tomography image integration into the EnSite NavX mapping system to perform catheter ablation of atrial fibrillation

Introduction: The complex anatomy of the left atrium (LA) makes location of ablation catheters difficult using fluoroscopy alone, and therefore 3D mapping systems are now routinely used. We describe the integration of a CT image into the EnSite NavX System with Fusion and its validation in patients undergoing atrial fibrillation (AF) or left atrial tachycardia (AT) catheter ablation. Methods and Results: Twenty‐three patients (61 ± 9.2 years, 16 male) with paroxysmal (14) and persistent (8) AF and persistent (1) AT underwent ablation using CT image integration into the EnSite NavX mapping system with the EnSite Fusion Dynamic Registration software module. In all cases, segmentation of the CT data was accomplished using the EnSite Verismo segmentation tool, although repeat segmentation attempts were required in seven cases. The CT was registered with the NavX‐created geometry using an average of 24 user‐defined fiducial pairs (range 9 to 48). The average distance from NavX‐measured lesion positions to the CT surface was 3.2 ± 0.9 mm (median 2.4 mm). A large, automated, retrospective test using registrations with random subsets of each patient's fiducial pairs showed this average distance decreasing as the number of fiducial pairs increased, although the improvement ceased to be significant beyond 15 pairs. In confirmation, those studies which had used 16 or more pairs had a smaller average lesion‐to‐surface distance (2.9 ± 0.7 mm) than those using 15 or fewer (4.3 ± 0.8 mm, P < 0.02). Finally, for the 13 patients who underwent left atrial circumferential ablation (LACA), there was no significant difference between the circumference computed using NavX‐measured positions and CT surface positions for either the left pulmonary veins (178 ± 64 vs. 177 ± 60 mm; P = 0.81) or the right pulmonary veins (218 ± 86 vs. 207 ± 81 mm; P = 0.08). Conclusion: CT image integration into the EnSite NavX Fusion system was successful in all patients undergoing catheter ablation. A learning curve exists for the Verismo segmentation tool; but once the 3D model was created, the registration process was easily accomplished, with a registration error that is comparable with registration errors using other mapping systems with CT image integration. All patients went on to have subsequent successful ablation procedures. Where LACA was performed (13 patients), only four patients required segmental ostial lesions to achieve electrical isolation.     

Regional amyloid distribution and impact on mortality in light-chain amyloidosis: a T1 mapping cardiac magnetic resonance study

Background: T1 mapping allows quantitative assessment of “diffuse” deposition of amyloid protein in the myocardium. Early detection of cardiac involvement and potential prognostic improvement could benefit patients with AL amyloidosis.

Objectives: This study aims to evaluate the regional variation of amyloid infiltration in the left ventricle and the prognostic value of T1 mapping in patients with AL amyloidosis.

Methods: We prospectively enrolled 77 patients with AL amyloidosis who underwent cardiac magnetic resonance on a 3.0-T scanner. Native T1 and extracellular volume (ECV) were quantitated on the basal, mid, and apical levels of the left ventricle. Late gadolinium enhancement (LGE) pattern (no or non-specific LGE, sub-endocardial LGE, and transmural LGE) was also assessed. Forty healthy subjects served as controls. The primary end point was all-cause mortality.

Results: Basal ECV (26.9?±?2.8% versus 31.1?±?4.9%, p?<?.001) were lower than apical ECV in the healthy controls; however, basal ECV (60.6?±?11.5% versus 53.0?±?9.6%, p?=?.003) were significantly higher than apical ECV in patients with transmural LGE. During the follow-up period (median duration, 28?months; 25th–75th percentile, 13.5–38.0?months), 46 patients died. Basal ECV has the largest area under the curve of 0.845 (95% CI, 0.747–0.917) to predict all-cause mortality. Multivariable Cox analysis indicated that basal ECV was an independent prognostic factor and showed incremental prognostic value beyond NYHA class, Mayo stage, and LGE pattern.

Conclusion: We demonstrated that T1 mapping may have the potential to detect a characteristic amyloid deposition with a decreasing gradient from base to apex. Furthermore, myocardial ECV indicated that basal amyloid infiltration provided robust and incremental prognostic value in patients with AL amyloidosis.     

颈动脉粥样硬化及血流动力学变化与脑梗死的关系

目的应用双功能彩色多普勒超声观察脑梗死患者颈动脉粥样硬化斑块和颈动脉各部位的血流动力学变化及其相互关系。方法经头颅CT和(或)MRI检查确诊的58例脑梗死患者(脑梗死组)及45例健康体检者(对照组),采用多普勒超声检测颈动脉内膜中层厚度(IMT),并同时检测颈总动脉及颈内动脉血流动力学指标。结果脑梗死组颈总动脉、颈内动脉及颈总动脉分叉部IMT均明显高于对照组(P<0.01);脑梗死组颈动脉粥样斑块检出率显著高于对照组(P<0.01);脑梗死组颈总动脉收缩期峰值流速、舒张末期流速及最大剪切率明显低于对照组,搏动指数、阻力指数高于对照组,脑梗死组颈内动脉舒张末期流速及最大剪切率明显低于对照组,阻力指数高于对照组;颈总动脉最大剪切率与颈总动脉IMT及颈总动脉分叉部IMT呈负相关,颈内动脉最大剪切率与颈内动脉IMT呈负相关。结论颈动脉IMT、斑块的部位和性质及血流动力学变化与脑梗死的发生密切相关。     

Combined local impedance and contact force for radiofrequency ablation assessment

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Simultaneous double-isotope autoradiographic measurement of local cerebral glucose metabolic rate and acid-base status in rat brain

We developed a double-isotope autoradiographic method for the simultaneous measurement of the local cerebral metabolic rate for glucose (1CMRG) and index of regional acid-base status (rABI) in single brain slices using [2-¹⁴C]deoxy-D-glucose (DG) and 5,5-dimethyl-[2-¹⁴C]oxazolidine-2,4, dione (DMO). After iv isotope administration, paper chromatography separates plasma DMO from DG activity using a methanol-methylene chloride solvent system. Initial tissue autoradiograms depict regional DMO plus DG and DG metabolite distribution. After 14 days in a well-ventilated hood, 97.5 ±0.5% of all DMO is lost from tissue sections by sublimation, and a second autoradiogram depicts DG plus DG metabolite distribution. Retention of brain lipids does not alter beta-particle self-absorption, avoiding problems associated with isotope extraction with solvents. Autoradiograms are digitized and converted to isotope-content images. The second autoradiogram is used for lCMRG computation. After subtracting the second regional isotope-content value from the first, the DMO content is obtained and used to compute rABI. Application of this method to normal animals yields expected values for lCMRG and rABI. This method is amenable to whole-slice digitization and creation of functional images of lCMRG and ABI followed by pixel-by-pixel correlations of the two variables, making this a potentially valuable tool for the investigation of the relationships between glucose metabolism and brain acid-base balance.     

Hormonal Replacement in Patients with Brain Injury-Induced Hypopituitarism: Who, When and How to Treat?

Traumatic brain injury is one of the main causes of death, as well as, physical and cognitive disabilities in young adults. Recent studies have demonstrated head injury (TBI and SAH) as a frequent cause of hypopituitarism. Since hormonal deficits may contribute to the outcome of the patient, it is important to establish guidelines of who, when, and how to treat. The probability of developing hypopituitarism has been based on the severity of the TBI. Yet discrepancies in recent studies display that minimal TBI can also result in hypopituitarism. Thus patients with moderate to severe TBI must be screened and those with minimal TBI monitored for hypopituitarism. The temporal relationship between TBI and occurrence of hypopituitarism is observed in 3 phases-acute, recovery, and chronic. Clear hormonal deficits should be treated, but the question arises concerning subtle abnormalities and their role in the outcome of TBI patients.     

Melatonin protects against ischemia/reperfusion-induced oxidative damage to mitochondria in fetal rat brain

We investigated the effects of melatonin on ischemia/reperfusion-induced oxidative damage to mitochondria in fetal rat brain. The utero-ovarian arteries were occluded bilaterally for 20 min in female Wistar rats on day 19 of pregnancy to induce fetal ischemia. Reperfusion was achieved by releasing the occlusion and restoring circulation for 30 min. A sham operation was performed in control rats. Melatonin (10 mg/kg) or vehicle was injected intraperitoneally 60 min prior to occlusion. We measured the respiratory control index (RCI) and the adenosine 5-diphosphate (ADP)/oxygen ratio as indicators of mitochondrial respiratory activity, as well as the concentration of thiobarbituric acid-reactive substances (TBARS) in the mitochondria of fetal brain. Ischemia/reperfusion significantly elevated the concentration of TBARS and significantly reduced the RCI as well as the ADP/oxygen ratio. Melatonin treatment reversed the ischemia/reperfusion-induced reductions in the RCI (2.29 +/- 0.06-2.64 +/- 0.09, P < 0.05) and in the ADP/oxygen ratio (1.48 +/- 0.03-1.57 +/- 0.02, P < 0.05), and also reduced the elevation in concentration of TBARS (11.00 +/- 0.34-7.57 +/- 0.74 nM/mg protein, P < 0.01), resulting in values similar to those in untreated, sham-ischemic animals. The results indicate that administration of melatonin to pregnant rats may prevent ischemia/reperfusion-induced oxidative mitochondrial damage in fetal rat brain.     

Headache and Liver Disease: Is Their Relationship More Apparent Than Real?

Headache is regarded by patients as a disturbing (or unpleasant) symptom. It can be produced by either organic diseases or functional head abnormalities. Twenty-five years ago headache was supposed to be a psychosomatic angiospastic algia. Certain unusual forms were thought to be caused by triggers like anger, cough, exertion, and sexual activity. Experimental research explored the role of circulating serotonin, prostaglandin, estrogen levels, and platelet abnormalities. As computed tomography, helical computed tomography, and scanning or magnetic resonance imaging evolved, new data became available. None of the newer reports have demonstrated liver involvement as a cause of headache. This minireview intends to cover the spectrum of brain alteration in liver disease. It describes some of the pathophysiological characteristics of hepatic encephalopathy and, also, the relationship among migraine, constipation, and liver disease.