人工耳蜗植入编程中NRT值和行为测试T值比较分析

目的:了解人工耳蜗植入编程中神经反应遥测(NRT)阈值与行为反应阈值的差别,寻找更好的编程方法。方法:对77例进行澳大利亚24型人工耳蜗植入的患儿在调试时对1、6、11、16、20号电极进行NRT值测试和行为T值测试,在能获得可靠的NRT和行为T值的时候收集数据,并进行统计学分析。结果:各个电极的vNRT值和行为T值的相关系数范围为0.40～0.54。各个电极vNRT的最小值为135μV,最大值为215μV。行为值的最小值为120CL,最大值为190CL。1,6,11,16,20号电极的vNRT和行为T差值的均值为27±14,24±13,31±14,26±13,20±13。vNRT和行为T值的最大差值为65,最小差值为-15。从20号电极到1号电极,平均T值幅度范围为148～159CL,平均vNRT值幅度范围为168～186μV,而且从低频电极到高频电极,vNRT值和行为T值呈上升趋势。结论:用vNRT阈值推测行为T值指导调机编程,个体差异较大,推测结果不是非常可靠,仅用于不能配合行为测试的患者。为了保证编程的准确性,最好对所有进行耳蜗编程的患者用行为T值来编程。     

Telemetry Bed Usage for Patients with Low-Risk Chest Pain: An Updated Review of the Literature for the Clinician

BackgroundTelemetry monitoring in patients with low-risk chest pain continues to be highly used despite a 2011 literature review and recommendations by the Clinical Practice Committee (CPC) of the American Academy of Emergency Medicine that did not find quality data to support its use.ObjectiveTo update the medical literature review on the utility of telemetry monitoring in patients with low-risk chest pain and to offer evidence-based recommendations to emergency physicians.MethodsA PubMed literature search was performed for systematic reviews in English relevant to low-risk chest pain between 2011 and 2019 and then expanded to all citations by removing the systematic review criteria. Studies identified then underwent a structured review from which results could be evaluated in the context of the associated 2011 literature review and CPC recommendations.ResultsThe initial search yielded 2 potentially relevant studies, although none directly addressed telemetry. The expanded search resulted in 76 abstracts that were screened. Two addressed telemetry, including the last CPC statement, which were reviewed and recommendations given.ConclusionsNo further quality data were identified to support the use of telemetry monitoring in patients with low-risk chest pains. Telemetry monitoring is unlikely to benefit patients with low-risk chest pain with a low-risk HEART Score.     

Inappropriate Implantable Cardioverter Defibrillator Shocks Secondary to Sensing Lead Failure: Utility of Stored Electrograms

The Ventritex Cadence is a fourth generation implanta-ble cardioverter defibrillator that provides for retrieval of stored eiectrograms related to therapy. In two patients, this feature enabled us to troubleshoot sensing lead problems, in one instance be/ore it became clinically apparent. This may be an important consideration in selecting an appropriate device.     

Relationship of Carbamazepine Reduction Rate to Seizure Frequency During Inpatient Telemetry

Summary: To establish guidelines for medication reduction during inpatient telemetry, the records of 18 children and young adults with refractory partial seizures undergoing carbamazepine (CBZ) reductions during continuous video/EEG telemetry were reviewed. Six patients were receiving CBZ monotherapy, and 12 patients were treated with an additional antiepileptic drug (AED) maintained at baseline dosage during CBZ taper. Despite relatively rapid mean reductions in dosage of 44% by day 2 of taper, no patients experienced frequent repetitive seizures or status epilepticus (SE). Seizure rate during the entire CBZ reduction period correlated significantly with rate of drug reduction. Linear regression analysis showed drug reduction rate to be a good predictor of seizure rate. Fourteen patients experienced at least three seizures during CBZ taper. On the average, the third seizure occurred on day 5 of taper at a percentage of dose seduction of 79%. In 8 patients, CBZ concentrations were measured both before taper and ≤24 h after the third seizure. For these patients, seizure rate also correlated significantly with reduction in CBZ level. We conclude that manipulation of CBZ dose reduction rate is important in maximizing seizure frequency during telemetry and, in our patients, a relatively rapid rate of dose reduction was safe and effective in promoting seizure recordings.     

Cardiac-directed expression of adenylyl cyclase and heart rate regulation

Abstract. Mice with cardiac-directed overexpression of AC_VI show increased cardiac responsiveness to -adrenergic receptor stimulation but regulation of heart rate is unknown. Telemetry was used to test the hypothesis that mice overexpressing cardiac adenylyl cyclase type VI (AC_VI) would have normal heart rate regulation. Mice overexpressing cardiac AC_VI were generated using the MHC promoter and studied 10 days after implantation of telemetry devices. Cardiac transgene AC_VI presence and expression was verified using PCR, RT-PCR and immunoblotting. Ambulatory heart rates were assessed using time and frequency domain analysis over two 24 hour light-dark cycles. Heart rates then were assessed following pharmacological blockade. Time domain analyses showed ambulatory heart rates were unchanged (AC_VI: 597 ± 15 (SEM) bpm, Control: 595 ± 12 bpm; p = 0.92). Circadian heart rate variability was preserved and not different from control mice (ANOVA, p = 0.52). Frequency domain analysis of heart rate variability also was unchanged. No difference in heart rate response to pharmacological autonomic blockade was found (intrinsic heart rate: AC_VI 622 ± 17 bpm, control 616 ± 16 bpm, p = 0.79). In conclusion, mice overexpressing cardiac AC_VI have normal conscious ambulatory heart rates and normal heart rate variability. Overexpression of cardiac AC_VI does not result in altered heart rate regulation in contrast to cardiac overexpression of other elements of the -adrenergic signaling pathway.This work was supported by Merit Awards (DMR) and (HKH) from the Department of Veterans Affairs, NIH 2P50 HL53773-06 (HKH), and NIH 1P01 HL66941-01A1 (HKH, DMR).     

人工耳蜗电极在耳蜗内不同部位的NRT阈值

目的通过对人工耳蜗电极在耳蜗内不同深度NRT阈值的检测，探讨耳蜗不同部位螺旋神经节对NRT反应阈值的差异。方法选择接受Nucleus CI 24M型人工耳蜗植入的15例患者，选择位蜗内最浅5个电极和最深5个电极区间，分别在蜗内3．20～7．05mm深（A组）和20．20～23．28mm深（B组）两个组，进行NRT阈值的检测。结果：A组NRT阈值为195．667±10．506，B组NRT阈值为182．200±14．339，两组比较，差异有显著性（P〈0．05）。结论位于蜗顶的NRT阈值比蜗底部低。     

Ambulatory Electrocardiogram Monitoring in Patients Undergoing Transcatheter Aortic Valve Replacement: JACC State-of-the-Art Review

Transcatheter aortic valve replacement (TAVR) has changed the treatment of patients with severe aortic stenosis. However, the occurrence of conduction disturbances has not decreased significantly over time and remains the main drawback of the procedure. In addition, new-onset atrial fibrillation is the most frequent tachyarrhythmia during the hospitalization period and is associated with worse clinical outcomes. However, little is known regarding the incidence and clinical impact of arrhythmic events beyond the periprocedural TAVR period. Ambulatory electrocardiogram (AECG) monitoring has recently emerged as a tool to unravel the complex issue of arrhythmic disorders (bradyarrhythmias and tachyarrhythmias) before and after TAVR. To date, the preliminary results from the initial experience using AECG monitoring systems showed the safety, usefulness, and potential clinical implications of this diagnostic tool in TAVR recipients. This review provides an overview of the current status, clinical implications, and future perspectives of AECG monitoring in the TAVR setting.