Loghin Catalin, Karimzadehnajar Kaveh, Ekeruo Ijeoma Ananaba, Mukerji Siddharth S, Memon Nada B, Kantharia Bharat K
The University of Texas Health Science Center at Houston, Memorial Hermann Hospital and Heart and Vascular Institute, 6431 Fannin Street, Suite MSB 1.246, Houston, TX, 77030, USA.
J Interv Card Electrophysiol. 2014 Jan;39(1):7-15. doi: 10.1007/s10840-013-9841-3. Epub 2013 Dec 6.
Although few clinical variables have been associated with recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) the role of left atrial (LA) mechanical function in the outcome of catheter ablation of AF is not adequately defined. The aim of our study was to determine whether LA mechanical dyssynchrony as evaluated by speckle tracking echocardiography can predict outcome of PVI ablation procedure in patients with paroxysmal AF.
Twenty-five patients (age 58 ± 11 years, [mean ± standard deviation], 17 males) with paroxysmal AF who met specific enrollment criteria pertaining to clinical presentation and follow-up, assessment of LA mechanical dyssynchrony, and strategy of catheter ablation procedure were enrolled. For LA mechanical dyssynchrony assessment, the time to peak longitudinal strain (TPk) in opposing walls in the midportion of the LA walls at peak atrial contraction in standard two- and four-chamber echocardiographic views by vector velocity imaging (VVI) was measured. Outcome of PVI procedure, whether no recurrence (NR) or AF recurrence (AFR) after 3 months of post-procedural blanking period, was evaluated based on AF-related symptoms and documentation of AF by electrocardiogram, continuous 24-h Holter, and intermittent event monitor recordings.
During a follow-up period of 20.3 ± 8.6 months, 18 out of 25 (72 %) patients had no recurrence (NR group), and 7 out of 25 (28 %) patients had recurrence of AF (AFR group). Significant gender difference was observed in terms of outcome such that all AFR patients were men and no woman had recurrence of AF. Between the NR and AFR groups, neither the left atrial diameter, 4.0 ± 0.3 and 4.2 ± 0.2 cm, respectively (p = 0.2), nor the left atrial volume indexes, 45 ± 15 and 48 ± 20 ml/m(2), respectively (p = 0.56), were statistically significantly different. For LA mechanical function, compared to the patients in NR group who had maximum opposing wall TPk delay of 39.9 ± 12.0 ms, those in the AFR group demonstrated significantly more LA mechanical dyssynchrony with maximum opposing wall TPk delay of 64.4 ± 17.0 ms prior to ablation (p = 0.007). Using receiver operative characteristic analyses of the data that had an area under the curve of 0.865, we identified a maximum opposing wall delay cutoff value of 51 ms which predicted AF recurrence with sensitivity and specificity values of 89 and 72 %, respectively (p = 0.005).
Speckle tracking strain analysis echocardiography can evaluate the LA mechanical dyssynchrony quantitatively. The severity of LA mechanical dyssynchrony by VVI can predict the outcome of PVI catheter ablation for paroxysmal AF.
尽管很少有临床变量与肺静脉隔离（PVI）术后房颤（AF）复发相关，但左心房（LA）机械功能在房颤导管消融结局中的作用尚未得到充分界定。我们研究的目的是确定经斑点追踪超声心动图评估的LA机械不同步是否能预测阵发性房颤患者PVI消融手术的结局。
纳入25例符合特定入选标准的阵发性房颤患者（年龄58±11岁，[均值±标准差]，17例男性），这些标准涉及临床表现和随访、LA机械不同步评估以及导管消融手术策略。对于LA机械不同步评估，通过向量速度成像（VVI）在标准二腔和四腔超声心动图视图中测量心房收缩峰值时LA壁中部相对壁的纵向应变峰值时间（TPk）。基于房颤相关症状以及心电图、连续24小时动态心电图和间歇性事件监测记录对房颤的记录，评估PVI手术后3个月无空白期后的结局，即无复发（NR）或房颤复发（AFR）。
在20.3±8.6个月的随访期内，25例患者中有18例（72%）无复发（NR组），25例中有7例（28%）房颤复发（AFR组）。在结局方面观察到显著的性别差异，即所有AFR患者均为男性，无女性房颤复发。NR组和AFR组之间，左心房直径分别为4.0±0.3和4.2±0.2 cm（p = 0.2），左心房容积指数分别为45±15和48±20 ml/m²（p = 0.56），均无统计学显著差异。对于LA机械功能，与NR组最大相对壁TPk延迟为39.9±12.0 ms的患者相比，AFR组在消融前最大相对壁TPk延迟为64.4±17.0 ms，显示出明显更多的LA机械不同步（p = 0.007）。使用曲线下面积为0.865的数据进行受试者操作特征分析，我们确定最大相对壁延迟截断值为51 ms，其预测房颤复发的敏感性和特异性值分别为89%和72%（p = 0.005）。
斑点追踪应变分析超声心动图可定量评估LA机械不同步。通过VVI评估的LA机械不同步严重程度可预测阵发性房颤PVI导管消融的结局。
