Santos José Ferreira, Parreira Leonor, Madeira João, Seixo Filipe, Mendes Lígia, Lopes Cláudia, Venâncio José, Lourenço José, Caetano Filomena, Inês Lopes, Mendes Miguel
Servico de Cardiologia, Hospital de SA Bernardo, Setúbal, Portugal.
Rev Port Cardiol. 2006 Jun;25(6):569-81.
Cardiac resynchronization therapy (CRT) is currently used in selected patients with dilated cardiomyopathy and heart failure. However, 30% of patients do not respond to CRT when selection is based on clinical and electrocardiographic criteria. Left ventricular dyssynchrony can be evaluated by tissue Doppler imaging and it has been described as a useful precdictor of response to CRT.
To evaluate whether left ventricular dyssynchrony, as measured by tissue Doppler imaging, can be used to predict response to CRT.
23 consecutive patients (age 67 +/- 10 years, 13 male) with heart failure refractory to medical therapy and who underwent CRT were studied. Before and six months after the procedure, various characteristics - clinical (including NYHA functional class), electrocardiographic (QRS interval) and echocardiographic (left ventricular ejection fraction [EF] and respective volumes)--were evaluated. In addition, pulsed wave tissue Doppler imaging was used to assess the time interval (QS) between the beginning of the QRS complex and the beginning of the systolic wave on the Doppler signal, in the basal segments of the septal, lateral, anterior and inferior walls. Left ventricular dyssynchrony was quantified as the difference between the maximum and minimum QS interval (QS(max-min)). The patients were divide into two groups: responders, if functional class improved by at least one and EF increased by more than 10%, and non-responders for the remainder. Differences between groups were assessed and predictors of response to CRT were determined.
CRT improved functional class by at least one in 87% of patients and EF improved from 21 +/- 6 to 33 +/- 9% (p < 0.001). QS(max-min) was reduced from 80 +/- 38 to 38 +/- 14 ms (p < 0.001). In 15 patients (65%), classified as responders, there was an improvement in functional class and an increase in EF of more than 10%. There were no differences between groups, except for QS(max-min). Patients in the responder group had greater left ventricular dyssynchrony (QS(max-min) 94 +/- 39 vs. 54 +/- 16 ms, p = 0.002). QSmix-min was an independent predictor of response to CRT and a cut-off of 60 ms identified responders with a sensitivity of 87% and specificity of 75%.
Despite the good results achieved with CRT, about one third of patients do not benefit from it. Left ventricular dyssynchrony can be quantified by tissue Doppler imaging using QS(max-min) and values greater than 60 ms can identify responders to CRT.
心脏再同步治疗（CRT）目前用于部分扩张型心肌病和心力衰竭患者。然而，当根据临床和心电图标准进行选择时，30%的患者对CRT无反应。左心室不同步可通过组织多普勒成像评估，并且已被描述为CRT反应的有用预测指标。
评估通过组织多普勒成像测量的左心室不同步是否可用于预测CRT反应。
对23例连续的心力衰竭患者（年龄67±10岁，13例男性）进行研究，这些患者药物治疗无效且接受了CRT。在手术前和术后6个月，评估各种特征——临床特征（包括纽约心脏协会功能分级）、心电图特征（QRS间期）和超声心动图特征（左心室射血分数[EF]和相应容积）。此外，使用脉冲波组织多普勒成像评估室间隔、侧壁、前壁和下壁基底段QRS波群起始至多普勒信号收缩波起始之间的时间间隔（QS）。左心室不同步量化为最大和最小QS间隔之差（QS(max-min)）。患者分为两组：反应者，如果功能分级至少改善一级且EF增加超过10%，其余为无反应者。评估组间差异并确定CRT反应的预测指标。
CRT使87%的患者功能分级至少改善一级，EF从21±6%提高到33±9%（p<0.001）。QS(max-min)从80±38毫秒降至38±14毫秒（p<0.001）。15例患者（65%）被归类为反应者，其功能分级改善且EF增加超过10%。除QS(max-min)外，组间无差异。反应者组患者的左心室不同步更大（QS(max-min) 94±39毫秒对54±16毫秒，p=0.002）。QS(max-min)是CRT反应的独立预测指标，60毫秒的临界值识别反应者的敏感性为87%，特异性为75%。
尽管CRT取得了良好效果，但约三分之一的患者并未从中获益。左心室不同步可通过使用QS(max-min)的组织多普勒成像进行量化，大于60毫秒的值可识别CRT反应者。
