University of Florence, Piazza di San Marco, 4, 50121 Firenze, Florence, Italy and IRCCS MultiMedica, Via Milanese, 300, 20099 Sesto San Giovanni (MI), Italy.
Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, 56127, Pisa, Italy.
Europace. 2018 May 1;20(5):794-800. doi: 10.1093/europace/euw446.
Discordant and concordant left bundle branch block (dLBBB/cLBBB) are characterized by negative or positive T waves, respectively, in lateral leads. We assessed if the two morphologies are associated with different clinical status and prognosis in patients with heart failure (HF) and current indication to Cardiac Resynchronization Therapy (CRT)/CRT-Defibrillator (CRT-D).
Baseline electrocardiograms of 1270 patients with LBBB in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy cohort were analysed to identify dLBBB and cLBBB. The two groups were compared with respect to baseline clinical characteristics, primary endpoint (HF event or death), and secondary endpoint (ventricular tachycardia, ventricular fibrillation, or death) over a 3.5-year period, and benefit of CRT-D over implantable cardioverter defibrillator (ICD). dLBBB was identified in 909 (72%) patients, and cLBBB in 361 (28%). Patients with dLBBB were older, had more severe symptoms and systolic dysfunction, as well as higher brain natriuretic peptide. CRT-D was superior to ICD in patients with both LBBB morphologies. The occurrence of the primary outcome was significantly more frequent in patients with dLBBB than in those with cLBBB, both in the entire cohort (P = 0.005), and in the CRT-D arm (P = 0.002). There was a trend towards more frequent occurrence of the secondary endpoint in patients with dLBBB than in those with cLBBB, but statistical significance was not reached in the whole population or in the subgroup undergoing CRT-D. Among patients receiving CRT-D, dLBBB was an independent predictor of the primary endpoint.
dLBBB morphology is associated with more severe HF clinical status and worse prognosis, even in patients receiving CRT-D, compared with cLBBB morphology.
左束支传导阻滞（LBBB）伴不同的左束支分支阻滞（dLBBB/cLBBB）形态特征分别为负向 T 波和正向 T 波。我们评估这两种形态在心力衰竭（HF）并伴有心脏再同步化治疗（CRT）/心脏再同步化除颤器（CRT-D）适应证的患者中是否与不同的临床状态和预后相关。
多中心自动除颤器植入试验-心脏再同步化治疗队列中 1270 例 LBBB 患者的基线心电图被分析以识别 dLBBB 和 cLBBB。两组在基线临床特征、主要终点（HF 事件或死亡）和次要终点（室性心动过速、室颤或死亡）方面进行了比较，随访时间为 3.5 年，并评估 CRT-D 相对于植入式心脏复律除颤器（ICD）的获益。909 例（72%）患者为 dLBBB，361 例（28%）为 cLBBB。dLBBB 患者年龄较大，症状和收缩功能更严重，脑钠肽更高。在两种 LBBB 形态的患者中，CRT-D 均优于 ICD。整个队列（P = 0.005）和 CRT-D 组（P = 0.002）中，dLBBB 患者的主要结局发生频率明显高于 cLBBB 患者。在整个人群或 CRT-D 亚组中，次要终点的发生频率也有向 dLBBB 患者增加的趋势，但未达到统计学意义。在接受 CRT-D 治疗的患者中，dLBBB 是主要终点的独立预测因子。
与 cLBBB 形态相比，dLBBB 形态与更严重的 HF 临床状态和更差的预后相关，即使在接受 CRT-D 的患者中也是如此。
