Computerized acoustic cardiographic insights into the pericardial knock in constrictive pericarditis

BACKGROUND: One of the clinical hallmarks of constrictive pericarditis is the pericardial knock, a high-pitched early diastolic heart sound. Making the clinical diagnosis of constrictive pericarditis is challenging, as is accurate auscultation of the pericardial knock. HYPOTHESIS: We sought to assess the utility of a computerized acoustic cardiographic device in the assessment of the pericardial knock in patients with constrictive pericarditis. METHODS: We report a case series in which computerized acoustic cardiography (Audicor, Inovise Medical Inc., Portland, OR) is performed in patients with constrictive pericarditis. RESULTS: Three patients with constrictive pericarditis underwent computerized acoustic cardiographic recordings at the time of cardiac catheterization. In each case, initial physical examination by the internist and referring cardiologist did not appreciate a pericardial knock. Acoustic cardiography demonstrated a high-pitched early diastolic sound in each case. Time-frequency representation analyses showed the high-frequency components of the pericardial knock sound. Repeat acoustic cardiography demonstrated resolution of the pericardial knock after pericardiectomy in two patients. CONCLUSIONS: Non-invasive computerized acoustic cardiography can demonstrate the high-pitched pericardial knock in patients with constrictive pericarditis. This may aid the bedside assessment of patients with diastolic heart failure, improving the clinician's ability to appreciate the ausculatory findings in constrictive pericarditis.     

Parallel input makes the brain run faster

In serial sensory processing, information flows from the thalamus via primary sensory cortices to higher-order association areas. However, association cortices also receive, albeit weak, direct thalamocortical sensory inputs of unknown function. For example, while information proceeds from primary (SI) to secondary (SII) somatosensory cortex in a serial fashion, both areas are known to receive direct thalamocortical sensory input. The present study examines the potential roles of such parallel input arrangements. The subjects were presented with median nerve somatosensory stimuli with the instruction to respond with the contralateral hand. The locations and time courses of the activated brain areas were first identified with magnetoencephalography (MEG). In a subsequent session, these brain areas were modulated with single-pulse transcranial magnetic stimulation (TMS) at 15-210 ms after the somatosensory stimulus while electroencephalography (EEG) was recorded. TMS pulses at 15-40 ms post-stimulus significantly speeded up reaction times and somatosensory-evoked responses, with largest facilitatory effects when the TMS pulse was given to contralateral SII at about 20 ms. To explain the results, we propose that the early somatosensory-evoked physiological SII activation exerts an SII-->SI influence that facilitates the reciprocal SI-->SII pathway - with TMS to SII we apparently amplified this mechanism. The results suggest that the human brain may utilize parallel inputs to facilitate long-distance cortico-cortical connections, resulting in accelerated processing and speeded reaction times. This arrangement could also allow very early top-down modulation of the bottom-up stream of sensory information.     

对陪护人员就老年脑血管病病人跌倒认知的调查

[目的]了解陪护人员对老年脑血管病病人跌倒认知的掌握情况,有针对性地实施教育。[方法]采用自行设计的调查表,对102例老年脑血管病病人的陪护人员进行调查,评定其对跌倒的认知。[结果]陪护人员文化程度偏低,对预防跌倒的相关知识不了解且缺乏正规的学习途径。[结论]医护人员应重视老年脑血管病陪护者的教育需求,有针对性地进行宣教。     

对陪护人员就老年脑血管病病人跌倒认知的调查

[目的]了解陪护人员对老年脑血管病病人跌倒认知的掌握情况，有针对性地实施教育。[方法]采用自行设计的调查表，对102例老年脑血管病病人的陪护人员进行调查，评定其对跌倒的认知。[结果]陪护人员文化程度偏低，对预防跌倒的相关知识不了解且缺乏正规的学习途径。[结论]医护人员应重视老年脑血管病陪护者的教育需求，有针对性地进行宣教。     

Permanent endovenous pediatric pacing: absence of lead failure--20 years follow-up study

Background: The aim of the study was to analyze endovenous pacing lead survival in pediatric population implanted by cephalic cut down, or by axillary vein puncture.
Methods: All implantations were performed in total endotracheal anesthesia, by the same surgeon. Implantations of ventricular leads were performed by cephalic vein cut down or by external jugular vein preparation. In dual-chamber pacing, atrial leads were implanted via cephalic vein (along with ventricular lead), by axillary vein puncture or via external jugular vein. All implanted leads were secured by resorbable suture.
Results: Over the 20-year follow-up period, 105 children of 5.7 years average age (range 1 day–15 years) were implanted with a permanent endovenous pacing system for congenital or postsurgical complete atrioventricular block or sinus node disease. Within the group, 27 patients (25.7%) weighed less than 10 kg on implantation. A total of 121 endovenous leads were implanted. All ventricular leads were with a passive fixation mechanism, and most of them unipolar (87.6%) and steroid eluting (94.2%). Leads implanted in atrial position were 82% bipolar, predominantly with active fixation (94%), and all steroid eluting. The most frequently used mode of stimulation was VVIR (66.6%). No acute or chronic lead displacement, exit block, sensing problem, lead conductor fracture, insulation defect or infections were observed during the total follow-up of 709 pacing years (average 6.9, range 0–20 years).
Conclusion: Implantation of the endovenous leads by preparation of the cephalic or puncture of the axillary vein, with lead fixation by resorbable suture represents a method of choice.     

Protein S down-regulates factor Xase activity independent of activated protein C: specific binding of factor VIII(a) to protein S inhibits interactions with factor IXa

Protein S functions as an activated protein C (APC)-independent anticoagulant in the inhibition of intrinsic factor X activation, although the precise mechanisms remain to be fully investigated. In the present study, protein S diminished factor VIIIa/factor IXa-dependent factor X activation, independent of APC, in a functional Xa generation assay. The presence of protein S resulted in an c. 17-fold increase in K(m) for factor IXa with factor VIIIa in the factor Xase complex, but an c. twofold decrease in K(m) for factor X. Surface plasmon resonance-based assays showed that factor VIII, particularly the A2 and A3 domains, bound to immobilized protein S (K(d); c. 10 nmol/l). Competition binding assays using Glu-Gly-Arg-active-site modified factor IXa showed that factor IXa inhibited the reaction between protein S and both the A2 and A3 domains. Furthermore, Sodium dodecyl sulphate polyacrylamide gel electrophoresis revealed that the cleavage rate of factor VIIIa at Arg(336) by factor IXa was c. 1.8-fold lower in the presence of protein S than in its absence. These data indicate that protein S not only down-regulates factor VIIIa activity as a cofactor of APC, but also directly impairs the assembly of the factor Xase complex, independent of APC, in a competitive interaction between factor IXa and factor VIIIa.     

Slowing down as an early warning signal for abrupt climate change

In the Earth's history, periods of relatively stable climate have often been interrupted by sharp transitions to a contrasting state. One explanation for such events of abrupt change is that they happened when the earth system reached a critical tipping point. However, this remains hard to prove for events in the remote past, and it is even more difficult to predict if and when we might reach a tipping point for abrupt climate change in the future. Here, we analyze eight ancient abrupt climate shifts and show that they were all preceded by a characteristic slowing down of the fluctuations starting well before the actual shift. Such slowing down, measured as increased autocorrelation, can be mathematically shown to be a hallmark of tipping points. Therefore, our results imply independent empirical evidence for the idea that past abrupt shifts were associated with the passing of critical thresholds. Because the mechanism causing slowing down is fundamentally inherent to tipping points, it follows that our way to detect slowing down might be used as a universal early warning signal for upcoming catastrophic change. Because tipping points in ecosystems and other complex systems are notoriously hard to predict in other ways, this is a promising perspective.     

Step‐down approach using either cyclosporin A or methotrexate as maintenance therapy in early rheumatoid arthritis

Objective

To evaluate the feasibility and outcome of the step‐down approach using either cyclosporin A (CSA) or methotrexate (MTX) as maintenance therapy following 6 months treatment with these 2 agents in combination in early, nonerosive rheumatoid arthritis (RA).

Methods

Fifty‐seven patients younger than 65 years with early, nonerosive RA were first treated with CSA and MTX in combination for 6 months. They were then randomly stepped down to single‐agent maintenance treatment for another 18 months. Safety, clinical efficacy, survival on treatment, and radiographic progression were evaluated.

Results

When being treated with combination therapy, 7 of the 57 patients (12.3%) withdrew because of adverse events. Of the remaining 50 patients, 42 (84.0%) were American College of Rheumatology (ACR) 20% responders, 30 (60.0%) were ACR 50% responders, and 23 (46.0%) were ACR 70% responders. At month 6, 22 patients were randomized to CSA and 27 to MTX. During this trial period, the treatment was discontinued by 16 patients taking CSA (mainly because of loss of efficacy) and by 4 taking MTX. At month 24, the probability (± SEM) of survival on treatment was 0.273 ± 0.09 for CSA and 0.852 ± 0.07 for MTX. Of the 6 CSA patients who completed the trial, 4 (66.7%) were ACR 20% responders, and 3 (50%) were both ACR 50% and ACR 70% responders. Of the 23 completers in the MTX arm, 21 (91.3%) were ACR 20% responders, 18 (78.3%) were ACR 50%, and 10 (43.5%) were ACR 70% responders. The treatment was not responsible for severe adverse events. Radiography showed a slow progression in the damage score and number of eroded joints in both treatment groups.

Conclusion

Stepping down to single agent maintenance therapy following 6 months of combination treatment with CSA and MTX in early RA was only successful with MTX. Because this treatment did not prevent some radiographic progression, other approaches (e.g., step‐up approach) may be more appropriate in early RA.

     

左心室Tei指数评价心电图ST段下移患者左心功能的临床价值

目的 探讨Tei指数评价体表心电图ST段下移患者左心功能的临床价值.方法 心电图ST段下移组患者31例,心电图无ST段改变健康者35例为对照组,超声心动图测量舒张末期及收缩期左室内径、室间隔和左室后壁厚度,舒张期E峰和A峰,计算左室射血分数、左室质量、二尖瓣频谱E/A及Tei指数.结果 ST段下移组心脏室间隔厚度、左室后壁厚度、左室质量、Tei指数较对照组增大,差异均有统计学意义(P<0.05).结论 Tei指数较射血分数、二尖瓣频谱E/A更能敏感地评价左心功能.