Cardiac resynchronization therapy in pediatric heart failure

The New York State Department of Health developed a Pediatric Cardiac Surgery Reporting System in 1991 that contains detailed information on demographics, diagnoses, procedures, comorbidities, complications, and discharge information for every pediatric cardiac surgery patient in the state. The Department and the Congenital Cardiac Services Subcommittee of the Department's Cardiac Advisory Committee have used data from this system to assess, assure, and improve quality of care and to generate public reports on an ongoing basis. Two reports (one covering 3 years and the other covering 4 years) have been published, and a third report, comprising the years 2006–2009, will be released shortly. These reports contain information on patient diagnoses, patient severity groups, and risk-adjusted in-hospital mortality rates for all hospitals that perform pediatric cardiac surgery. The goal of the DOH and the CAC is to improve the quality of cardiac care in NYS. Providing the hospitals and cardiac surgeons in NYS with data about their own outcomes for these procedures allows them to examine the quality of the care they provide and to identify areas that need improvement. These data are fed back to providers on an ongoing basis in addition to in the published reports. The overall results of this program of ongoing review show that significant progress is being made.The volume of surgeries and the number of hospitals where they are performed have both decreased dramatically in the years since NYS first began reporting risk-adjusted outcomes for pediatric cardiac surgery. In 1997, 16 hospitals performed 1749 pediatric cardiac surgeries. By 2009, there were only 10 hospitals performing 1304 surgeries. The average number of surgeries per hospital in 1997 was 109 compared to 139 in 2010. Many factors, including increased use of catheter-based therapies, may have contributed to the overall decline in the number of surgeries. The overall mortality rate for pediatric cardiac surgery dropped from 4.08% in 2002 to 2005 period to a mortality rate of 3.35% in 2006 to 2009 period with no major changes in overall patient risk, although part of this decrease may also be due to improvements in the field in general. A multivariable analysis demonstrated that a dedicated pediatric cardiac ICU proved to be a significant independent predictor of mortality. The methods for assessing patients' risk of in-hospital mortality have changed with each successive report, and this study describes the current method and the risk factors used in the method. The Department's other initiatives for improving quality, including consolidation of services, linking processes and structures of care to outcomes, and other regulatory actions, are also described.     

A CMR study of the effects of tissue edema and necrosis on left ventricular dyssynchrony in acute myocardial infarction: implications for cardiac resynchronization therapy

Background

In acute myocardial infarction (AMI), both tissue necrosis and edema are present and both might be implicated in the development of intraventricular dyssynchrony. However, their relative contribution to transient dyssynchrony is not known. Cardiovascular magnetic resonance (CMR) can detect necrosis and edema with high spatial resolution and it can quantify dyssynchrony by tagging techniques.

Methods

Patients with a first AMI underwent percutaneous coronary interventions (PCI) of the infarct-related artery within 24 h of onset of chest pain. Within 5–7 days after the event and at 4 months, CMR was performed. The CMR protocol included the evaluation of intraventricular dyssynchrony by applying a novel 3D-tagging sequence to the left ventricle (LV) yielding the CURE index (circumferential uniformity ratio estimate; 1 = complete synchrony). On T₂-weighted images, edema was measured as high-signal (>2 SD above remote tissue) along the LV mid-myocardial circumference on 3 short-axis images (% of circumference corresponding to the area-at-risk). In analogy, on late-gadolinium enhancement (LGE) images, necrosis was quantified manually as percentage of LV mid-myocardial circumference on 3 short-axis images. Necrosis was also quantified on LGE images covering the entire LV (expressed as %LV mass). Finally, salvaged myocardium was calculated as the area-at-risk minus necrosis (expressed as % of LV circumference).

Results

After successful PCI (n = 22, 2 female, mean age: 57 ± 12y), peak troponin T was 20 ± 36ug/l and the LV ejection fraction on CMR was 41 ± 8%. Necrosis mass was 30 ± 10% and CURE was 0.91 ± 0.05. Edema was measured as 58 ± 14% of the LV circumference. In the acute phase, the extent of edema correlated with dyssynchrony (r² = −0.63, p < 0.01), while extent of necrosis showed borderline correlation (r² = −0.19, p = 0.05). PCI resulted in salvaged myocardium of 27 ± 14%. LV dyssynchrony (=CURE) decreased at 4 months from 0.91 ± 0.05 to 0.94 ± 0.03 (p < 0.004, paired t-test). At 4 months, edema was absent and scar %LV slightly shrunk to 23.7 ± 10.0% (p < 0.002 vs baseline). Regression of LV dyssynchrony during the 4 months follow-up period was predicted by both, the extent of edema and its necrosis component in the acute phase.

Conclusions

In the acute phase of infarction, LV dyssynchrony is closely related to the extent of edema, while necrosis is a poor predictor of acute LV dyssynchrony. Conversely, regression of intraventricular LV dyssynchrony during infarct healing is predicted by the extent of necrosis in the acute phase.     

超声测量心外膜脂肪组织厚度在慢性心力衰竭患者中的临床价值

目的 :探讨采用超声测量心外膜脂肪组织(epicardial adipose tissue,EAT)厚度,研究其评价慢性收缩性心力衰竭(心衰)患者心脏重构、心功能参数、电机械同步性等的临床价值。方法:选择78例心衰患者,平均左心室射血分数(left ventricular ejection fraction,LVEF)为31.8%±7.9%,住院期间接受常规超声心动图和组织多普勒检查,并测量EAT厚度。另选择同期健康体检者30名作为对照进行比较分析。结果:1超声测量心衰患者的右室前壁EAT厚度范围在0.3~10.2 mm间,平均厚度为(3.6±2.1)mm,其EAT厚度较对照者[(4.9±1.5)mm]显著降低(P=0.03);根据QRS宽度将心衰患者分为2组,QRS宽度≥120 ms者的EAT厚度又显著低于QRS宽度     

二维应变参数评价扩张型心肌病患者左心室收缩同步性及其与心功能的关系

目的 探讨二维斑点追踪成像（2D-STI）应变参数评价扩张型心肌病（DCM）患者左心室收缩同步性的价值及其与心功能的关系。方法 收集DCM患者（DCM组）及对照组各25例,采用2D-STI技术获取左心室各节段纵向应变达峰时间、圆周应变达峰时间（Tls、Tcs）,分别计算左心室18节段纵向应变达峰时间标准差（Tls-SD）及最大差值（Tls-dif）,左心室心尖四腔心、三腔心、二腔心切面6节段纵向应变达峰时间标准差（Tls-SD-4、Tls-SD-3、Tls-SD-2）及最大差值（Tls-dif-4、Tls-dif-3、Tls-dif-2）,左心室18节段圆周应变达峰时间标准差（Tcs-SD）及最大差值（Tcs-dif）,左心室短轴二尖瓣、乳头肌、心尖水平6节段圆周应变达峰时间标准差（Tcs-SD-M、Tcs-SD-P、Tcs-SD-A）及最大差值（Tcs-dif-M、Tcs-dif-P、Tcs-dif-A）。结果 与对照组比较,DCM组整体及节段应变参数均显著增大（P均<0.05）;DCM组中,除Tcs-dif-P、Tcs-dif外,余应变参数均与左心室射血分数呈负相关（P均<0.05）;除Tcs-dif-M、Tcs-dif-P及Tcs-dif外,余应变参数均与舒张早期二尖瓣口峰值血流速度（E）/二尖瓣环运动速度（e）呈正相关（P均<0.05）。结论 DCM患者左心室整体及局部收缩期应变均存在不同步,收缩不同步可加剧心功能的恶化;2D-STI参数可以客观评价DCM患者左心室收缩不同步及其与心功能的关系。     

组织同步显像评价左心室内收缩失同步

目的 应用组织同步显像(TSI)观察左心室内心肌收缩运动失同步,探讨快速准确判定心室内运动不协调的方法。 方法 收集完全性左束支传导阻滞患者(LBBB组)28例及正常志愿者(对照组)28名,以TDI测量左心室12节段的收缩达峰时间(Ts),计算收缩达峰时间的标准差(Ts-SD)。分别设定不同的TSI处理时间,根据二维图像显示的色彩计算TSI积分。 结果 与对照组相比,LBBB组Ts延长,Ts-SD增大,TSI积分明显增加。LBBB组共有36个节段(36/336,10.71%)存在严重收缩后收缩(PSS)现象。TSI处理时间设定在收缩期时与等容舒张期时的严重PSS节段的平均TSI积分与仅设定在收缩期时差异有统计学意义(3.60±0.37 vs 2.30±0.48,P<0.001)。 结论 在正确设定处理时间的前提下,利用TSI可以直观评价左心室心肌收缩运动不同步。     

QRS width does not reflect ventricular dyssynchrony in patients with heart failure

The purpose of this study was to evaluate QRS width as an indication for cardiac resynchronization therapy. This study group consisted of 64 heart failure patients (51 men, age average 60.5 ± 15.5 years) with a left ventricular ejection fraction (LVEF) of less than 35%. Patients were divided into two groups according to their QRS width; the wide QRS group (QRS width greater than or equal to 120 ms, 31 patients) and the narrow QRS group (QRS width less than 120 ms, 33 patients). The ventricular dyssynchrony (VD), i.e., the inter- and intraventricular dyssynchrony, of the two groups was compared. The correlation between QRS width and VD was evaluated in all patients. There were no significant differences between the wide and the narrow QRS groups concerning interventricular dyssynchrony [28.4 ± 26.1 ms vs. 25.3 ± 18.2 ms, not significant (NS)] or intraventricular dyssynchrony (99.0 ± 43.8 ms vs. 109.0 ± 56.6 ms, NS). Nor were there any differences in the LVEF (26.6 ± 6.6% vs. 28.2 ± 5.1%, NS), brain natriuretic peptide (BNP) (567.0 ± 319.0 pg/ml vs. 390.0 ± 375.8 pg/ml, NS), and New York Heart Association (NYHA) class (2.4 ± 0.8 vs. 2.0 ± 1.0, NS). QRS width did not correlate with interventricular (r = 0.026, NS) or intraventricular dyssynchrony (r = 0.052, NS). There were no differences in VD between the two groups based on differences in QRS width. There was also no correlation between QRS width and VD. It is suggested that QRS width is not an absolute indication for cardiac resynchronization therapy.