Sénéchal Mario, Lancellotti Patrizio, Garceau Patrick, Champagne Jean, Dubois Michelle, Magne Julien, Blier Louis, Molin Frank, Philippon François, Dumesnil Jean G, Pierard Luc, O'Hara Gilles
Department of Cardiology, Institut de Cardiologie de Québec, Hôpital Laval, Québec, Canada.
Echocardiography. 2010 Jan;27(1):50-7. doi: 10.1111/j.1540-8175.2009.00962.x. Epub 2009 Aug 31.
It has been hypothesized that a long-term response to cardiac resynchronization therapy (CRT) could correlate with myocardial viability in patients with left ventricular (LV) dysfunction. Contractile reserve and viability in the region of the pacing lead have not been investigated in regard to acute response after CRT.
Fifty-one consecutive patients with advanced heart failure, LV ejection fraction <or= 35%, QRS duration > 120 ms, and intraventricular asynchronism >or= 50 ms were prospectively included. The week before CRT implantation, the presence of viability was evaluated using dobutamine stress echocardiography. Acute responders were defined as a >or=15% increase in LV stroke volume.
The average of viable segments was 5.8 +/- 1.9 in responders and 3.9 +/- 3 in nonresponders (P = 0.03). Viability in the region of the pacing lead had an excellent sensitivity (96%), but a low specificity (56%) to predict acute response to CRT. Mitral regurgitation (MR) was reduced in 21 patients (84%) with acute response. The presence of MR was a poor predictor of response (sensibility 93% and specificity 17%). However, combining the presence of MR and viability in the region of the pacing lead yields a sensibility (89%) and a specificity (70%) to predict acute response to CRT.
Myocardial viability is an important factor influencing acute hemodynamic response to CRT. In acute responders, significant MR reduction is frequent. The combined presence of MR and viability in the region of the pacing lead predicts acute response to CRT with the best accuracy.
有假说认为，心脏再同步治疗（CRT）的长期反应可能与左心室（LV）功能不全患者的心肌存活性相关。关于CRT术后急性反应，尚未对起搏导线区域的收缩储备和存活性进行研究。
前瞻性纳入51例连续的晚期心力衰竭患者，左心室射血分数≤35%，QRS时限>120 ms，室内不同步≥50 ms。在CRT植入前一周，使用多巴酚丁胺负荷超声心动图评估心肌存活性。急性反应者定义为左心室每搏量增加≥15%。
反应者存活节段的平均值为5.8±1.9，无反应者为3.9±3（P = 0.03）。起搏导线区域的存活性对预测CRT急性反应具有极佳的敏感性（96%），但特异性较低（56%）。21例（84%）有急性反应的患者二尖瓣反流（MR）减轻。MR的存在对反应的预测较差（敏感性93%，特异性17%）。然而，将MR的存在与起搏导线区域的存活性相结合，对预测CRT急性反应的敏感性为89%，特异性为70%。
心肌存活性是影响CRT急性血流动力学反应的重要因素。在急性反应者中，MR显著减轻很常见。MR的存在与起搏导线区域的存活性相结合，对CRT急性反应的预测准确性最高。
