Cochlear implantation in children with auditory neuropathy spectrum disorders

Abstract

Aim

To present the outcomes of cochlear implantation (CI) in children with auditory neuropathy spectrum disorders (ANSD).

Materials and methods

The pre- and post-CI hearing outcomes in children with ANSD were retrospectively evaluated. Performance was assessed with categories of auditory performance (CAP) and the Manchester spoken language development scale (MSLDS).

Results

Full data were available in 27 implanted children with ANSD with average age at implantation 35.4 months (range 19–68 months). Nine children were implanted bilaterally, while 13 were bimodal. The pre-CI CAP and MSLDS scores were 2.5 (range 0–5) and 2.5 (range 0–6), while the post-CI scores 5.8 (range 2–9) and 7.7 (range 3–10), respectively.

Conclusions

Although the outcome of CI in children with ANSD might vary, it is favourable in most of the cases. CI seems a justified hearing rehabilitation option for children with ANSD and limited benefits from conventional hearing aids.     

实时三维超声心动图评价心肌梗死后心力衰竭患者左心室收缩功能与不同步性

目的 探讨实时三维超声心动图评价心肌梗死后心力衰竭患者左心室收缩功能与不同步性的临床价值。方法对40例心肌梗死后心力衰竭患者（心肌梗死组）及30例健康者（对照组）分别行左室实时三维超声心动图17节段时间一容积分析,获取左室整体收缩功能指标：左室舒张末期容积（LVEDV）、收缩末期容积（LVESV）、射血分数（LVEF）;左室收缩同步性指标：除心尖帽外的16节段从QRS波起点到最小收缩容积的时间的标准差和最大差值（Tmsv16-SD、Tmsv16-Dif）;二者除以心动周期分别得到SDI、Tmsv16-Dif％。分析LVEF与SDI之间的关系。结果与对照组比较,心肌梗死组左室扩大,LVEDV、LVESV增高,LVEF减低,差异均有统计学意义（P〈0．01）,LVEF与LVEDV呈负相关（r=-0．83,P〈0．01）;心肌梗死组SDI高于对照组（P〈0．01）,SDI与LVEF呈负相关（r=0．84,P〈0．01）。结论陈旧性心肌梗死患者左心室重构明显,不但心功能减低而且普遍存在收缩不同步,不同步程度与收缩功能呈负相关。实时三维超声心动图能同时提供左室收缩功能和不同步性的详细信息,是评价心功能的有效手段。     

超声心动图评价左心室收缩失同步

目的 应用组织多普勒及常规超声心动图观察左束支传导阻滞患者左心室心肌收缩运动失同步.方法 完全性左束支传导阻滞者(LBBB)20例,正常对照者20例.定量组织多普勒测量左室基底及中段共12个节段的收缩达峰时间(TS),并计算其变异系数(标准差/均值)作为收缩不同步指数(SDI).同时测量心肌做功指数(MPI)、左室射血分数(EF)及充盈时间(FT).结果 与正常组相比,LBBB组的患者左室收缩明显延迟,12个节段TS的均值明显延长(P<0.001).其SDI显著增大(P<0.001).LBBB组的MPI增大,EF、FT均显著减小(P<0.001).结论 LBBB患者的左室壁各节段出现不同程度的收缩延迟,对左室的整体功能存在影响.定量组织多普勒观察心室电-机械耦联情况,结合对左室整体功能的测定,可以综合评价左心室收缩的失同步.     

Chronic Left Ventricular Pacing Preserves Left Ventricular Function in Children

Chronic right ventricular (RV) pacing can induce structural and functional cardiac deterioration. Because animal studies showed a benefit of left ventricular (LV) over RV pacing, this study compared the effects of chronic RV and LV pacing in children. Retrospectively, echocardiographic data were evaluated from 18 healthy children (control subjects) and from children undergoing chronic epicardial RV pacing (7 RVP) or LV pacing (7 LVP). Assessment included LV end-diastolic wall thickness (LVEDWT) and end-systolic wall thickness (LVESWT) as well as LV end-diastolic diameter (LVEDD) and end-systolic diameter (LVESD). The shortening fraction and eccentricity index (LV diameter/2xLV wall thickness) were calculated as measures of LV function and eccentricity, respectively. Duration of QRS and septal posterior wall motion delay (SPWMD) were used as measures of electrical and mechanical dyssynchrony, respectively. A p value less than 0.05 determined significance. As the findings showed, LVEDD, LVESD, LVEDWT, and LVESWT were not significantly different between the groups. The shortening fraction was significantly lower in the RVP (21.7%+/-6.0%) than in the LVP (32.2%+/-5.2%) or control (29.3%+/-4.3%) children. The systolic LV eccentricity index was significantly larger in the RVP (1.8+/-0.2) than in the LVP (1.4+/-0.1) or control (1.4+/-0.2) children. The SPWMD was significantly larger in the RVP (338+/-20 ms) than in the LVP (-16+/-14 ms) or control (-5+/-35 ms) group, whereas QRS duration was similarly longer in the RVP (157+/-10 ms) and LVP (158+/-22 ms) groups compared than in the control group (69+/-7 ms). The authors conclude that LV function in children is preserved by chronic pacing at the LV lateral wall.     

The effect of pharmacological stress on intraventricular dyssynchrony in left ventricular systolic dysfunction

BACKGROUND: Cardiac resynchronisation therapy (CRT) improves symptoms and exercise capacity in many patients with heart failure (HF) who have left ventricular systolic dysfunction (LVSD) and markers of dyssynchrony. LV dyssynchrony is conventionally measured at rest but the symptoms of heart failure occur predominantly on exercise. Induction or exacerbation of dyssynchrony during stress might identify additional patients who could benefit from CRT. METHODS AND RESULTS: Seventy-seven patients (47 with QRSd<120 ms and 30 with QRSd>120 ms) with heart failure due to left ventricular systolic dysfunction and 22 normal subjects underwent dobutamine stress echocardiography using colour tissue Doppler imaging. Left intraventricular dyssynchrony was measured as the standard deviation of the time to peak velocity from the onset of the QRS (Ts-SD) and the difference between the maximum and minimum time to peak velocity (Tscor-diff) in the 12 non-apical segments at rest and during peak stress. Timings were corrected for heart rate. The mean values of these indices increased with stress in both groups of patients but not in control subjects (p<0.001). The prevalence of conventionally-defined dyssynchrony also increased with stress. CONCLUSION: In patients with heart failure, the severity and the prevalence of intraventricular dyssynchrony increase with stress. Whether stress-induced dyssynchrony will identify patients who might benefit from CRT awaits further research.     

Prediction of response to cardiac resynchronization therapy using left ventricular pacing lead position and cardiovascular magnetic resonance derived wall motion patterns: a prospective cohort study

Background

Despite marked benefits in many heart failure patients, a considerable proportion of patients treated with cardiac resynchronization therapy (CRT) fail to respond appropriately. Recently, a “U-shaped” (type II) wall motion pattern identified by cardiovascular magnetic resonance (CMR) has been associated with improved CRT response compared to a homogenous (type I) wall motion pattern. There is also evidence that a left ventricular (LV) lead localized to the latest contracting LV site predicts superior response, compared to an LV lead localized remotely from the latest contracting LV site.

Methods

We prospectively evaluated patients undergoing CRT with pre-procedural CMR to determine the presence of type I and type II wall motion patterns and pre-procedural echocardiography to determine end systolic volume (ESV). We assessed the final LV lead position on post-procedural fluoroscopic images to determine whether the lead was positioned concordant to or remote from the latest contracting LV site. CRT response was defined as a ≥ 15 % reduction in ESV on a 6 month follow-up echocardiogram.

Results

The study included 33 patients meeting conventional indications for CRT with a mean New York Heart Association class of 2.8 ± 0.4 and mean LV ejection fraction of 28 ± 9 %. Overall, 55 % of patients were echocardiographic responders by ESV criteria. Patients with both a type II pattern and an LV lead concordant to the latest contracting site (T2CL) had a response rate of 92 %, compared to a response rate of 33 % for those without T2CL (p = 0.003). T2CL was the only independent predictor of response on multivariate analysis (odds ratio 18, 95 % confidence interval 1.6-206; p = 0.018). T2CL resulted in significant incremental improvement in prediction of echocardiographic response (increase in the area under the receiver operator curve from 0.69 to 0.84; p = 0.038).

Conclusions

The presence of a type II wall motion pattern on CMR and a concordant LV lead predicts superior CRT response. Improving patient selection by evaluating wall motion pattern and targeting LV lead placement may ultimately improve the response rate to CRT.     

Selecting patients for cardiac resynchronization therapy: electrical or mechanical dyssynchrony?

Cardiac resynchronization therapy (CRT) markedly reduces morbidity and mortality in patients with heart failure and prolonged QRS duration. Landmark trials have included over 4000 patients based on their electrocardiogram. A few small, observational, non-randomized, single centre studies of short duration have suggested that echocardiographic measurement of mechanical dyssynchrony may better identify patients likely to benefit from CRT. We objectively review the meaning and measurement of electrical and mechanical dyssynchrony, the strengths and weaknesses of echocardiographic indices of dyssynchrony, and the controversial issue of predicting response to treatment. We conclude that proposals to alter current guidelines for patient selection, and include echocardiography, are misguided. Echocardiographic assessment will only become credible and applicable to clinical practice once used to select patients for large prospective randomized trials which show an improvement in clinical outcome.     

Upgrade to biventricular pacing in patients with pacing-induced heart failure: can resynchronization do the trick?

Dyssynchrony imposed on ventricular function by right ventricular (RV) apical pacing may lead in some cases to worsening or appearance of heart failure (HF) symptoms. This is a result of an altered pattern of activation, leading to several histological and functional adjustments of the left ventricle, including inhomogeneous thickening of the ventricular myocardium and myofibrillar disarray, fibrosis, disturbances in ion-handling protein expression, myocardial perfusion defects, alterations in sympathetic tone and mitral regurgitation. Studies of mid- and long-term effects of RV apical pacing on left ventricular (LV) function have demonstrated a progressive decline in ejection fraction and other indices of LV functional competence. Upgrading RV pacing systems to biventricular resynchronization modalities is a theoretically promising option for paced patients with worsening HF. The potentially favourable effect of upgrading on LV functional indices and patient clinical status has been demonstrated in few, non-randomized trials. Apart from the scantiness of existing clinical data, issues concerning technical aspects of the procedure and selection of eligible patients are raised. Is pacing-induced dyssynchrony equivalent to the indigenous dyssynchrony in unpaced patients with HF? What selection criteria should be applied in order to identify potential responders to cardiac resynchronization therapy in this patient population? Answers to these and more questions are still lacking.     

二尖瓣环运动组织速度显像对心力衰竭患者左心室功能的评价

目的 应用组织速度显像(TVI)研究二尖瓣环运动以评价心力衰竭患者左心室功能的价值.方法 测量210例左室射血分数(EF)≤45%(Simpson法)的心衰患者(CHF组)及15例正常人(对照组)不同切面二尖瓣环,TVI曲线,测定等容收缩期、射血期、舒张期各时相的持续时间(IVC、S、D)、IVC/S,以及心电图QRS波起点到S波顶点的时间(TTP)、等容收缩期波峰的加速时间(IVA),并计算不同室壁各指标标准差.结果 CHF组IVC明显延长,S、D明显缩短,IVC/S明显增大,而各指标的标准差即IVC-SD、S-SD、IVC/S-SD、D-SD、TTP-SD、IVA-SD均明显增大.结论 应用TVI分析二尖瓣环运动,可敏感评估心衰患者左心室功能障碍和室壁运动不同步.