左心房容积与冠状动脉旁路移植术后心房颤动相关性的研究

目的:评价冠状动脉旁路移植术(CABG)前,二维超声心动图估测左心房容积指数(LAVI)与术后心房颤动发生的相关性。方法:入选北京同仁医院2010年1月至2012年6月期间,入院实施CABG术的冠心病患者106例进行前瞻性分析。将患者分为术后心房颤动组和术后未发生心房颤动组。采用多因素Logistic回归分析,评价术前通过二维超声心动图估测的LAVI值与术后心心房颤动动发生的相关性。结果:CABG术后发生心房颤动患者19例,术后心房颤动发生率为17.9%。术后心房颤动组的LAVI值显著高于术后未发生心房颤动组[(22.1±4.1)vs.(18.1±5.1)m L/m2,P=0.018]。多元logistic回归分析显示,年龄(OR=1.015,95%CI:1.017~1.0323,P=0.026)、高血压病史(OR=1.053,95%CI:1.019~1.087,P=0.009)、既往心房颤动病史(OR=2.273,95%CI:1.207~3.340,P=0.010)、LAV值(OR=1.784,95%CI:1.181~2.487,P=0.003)是CABG后心房颤动发生的独立危险因素。结论:CABG术前通过二维超声心动图估测的LAVI值是冠心病患者CABG术后心房颤动发生的独立危险因素,对于预测CABG术后心房颤动发生并进行危险分层具有一定参考价值。     

Predictive value of total atrial conduction time measured with tissue Doppler imaging for postoperative atrial fibrillation after coronary artery bypass surgery

Objective

Postoperative atrial fibrillation (POAF) complicating coronary artery bypass grafting surgery (CABG) increases morbidity and stroke risk. Total atrial conduction time (PA-TDI duration) has been identified as an independent predictor of new-onset atrial fibrillation (AF). We aimed to assess whether PA-TDI duration is a predictor of AF after CABG.

Methods

In 128 patients who had undergone CABG, preoperative clinical and echocardiographic data were compared between patients with and without POAF. The PA-TDI duration was assessed by measuring the time interval between the beginning of the P wave on the surface ECG and point of the peak A wave on TDI from left atrium (LA) lateral wall just over the mitral annulus.

Results

Patients with POAF (38/128, 29.6 %) were older (68.1?±?11.1 vs. 59.3?±?10.2 years; p?<?0.001), had higher LA maximum volume, had prolonged PA-TDI duration, and had lower ejection fraction compared with patients without POAF. PA-TDI duration was found to be significantly increased in POAF group (134.3?±?19.7 vs. 112.5?±?17.7 ms; p?=?0.01). On multivariate analysis, age (95 % CI?=?1.03–1.09; p?=?0.003), LA maximum volume (95 % CI?=?1.01–1.06; p?=?0.03), and prolonged PA-TDI duration (95 % CI, 1.02–1.05; p?=?0.001) were found to be the independent risk factors of POAF.

Conclusions

In this study, LA maximum volume and PA-TDI duration were found to be the independent predictors of the development of POAF after CABG. Echocardiographic predictors of left atrial electromechanical dysfunction may be useful in risk stratifying of patients in terms of POAF development after CABG.     

老年心血管病患者房颤反复发作的预测

目的　为明确老年心血管疾病患者窦性心律时发生阵发性房颤的危险因素并寻找反复心房颤动发作的预测因子。方法　测量 71例有阵发性房颤发作史的老年心血管疾病患者 (PAF组 )及 73例无阵发性房颤发作史的老年心血管疾病患者 (对照组 )窦性心律时的 12导联ECG ,分别测定最大P波时限 (Pmax)及最小P波时限 (Pmin)并计算其P波离散度 (Pd) ,心脏超声测量左房内径 (LAD)和左室射血分数 (LVEF) ,随访PAF组房颤反复发作情况。结果　PAF组的Pd及Pmax分别为 ( 4 7.0 7± 12 .3 5 )ms和 ( 12 1.2 5± 13 .2 4)ms,较对照组明显延长 (P <0 .0 1) ;PAF组反复房颤发作者 ,Pd≥40ms时相对危险度 3 .3 3 ,Pmax≥ 110ms时相对危险度 2 .48。结论　窦性心律时Pd、Pmax增加是预测老年心血管病患者是否发生房颤及房颤反复发作的有效且无创的临床方法     

Reduced Peak Atrial Systolic Mitral Annular Velocity Predicts the Development of Nonvalvular Atrial Fibrillation

We investigated whether the echocardiographic parameters of the left atrium (LA) can predict the development of nonvalvular atrial fibrillation (AF). Among 14,062 patients ( > 20 years old) who underwent an echocardiographic examination were evaluated, 2,606 patients who underwent follow-up ECG with an interval of > 6 months were investigated. Newly developed AF was noted in 42 (1.6%) patients with follow-up duration of 31.8 ± 8.9 months. Cox regression analysis revealed that a higher left atrial volume index (hazard ratio [HR ]= 1.06; 95% confidence interval [CI] 1.03–1.09, P < 0.001), relative wall thickness (RWT) of ≥ 0.407 (HR = 2.74, 95% CI 1.39–5.41, P = 0.004), a reduced peak atrial systolic mitral annular velocity (HR = 0.845, 95% CI 0.72–0.99, P = 0.037), and an advanced age (HR = 1.04, 95% CI 1.01–1.07, P = 0.009) were independently related to the development of nonvalvular AF. Therefore, reduced A ' , which is parameter of LA contractile function, might be an important predictor for the development of nonvalvular AF.     

典型心房扑动射频消融术后发生心房颤动患者的心房电生理特性

分析典型心房扑动(简称房扑)射频消融术后发生心房颤动(简称房颤)患者的心房电生理特性,探讨心房内传导时间在房颤发生中的意义。56例典型房扑患者,其中19例有器质性心脏病,16例在消融前有房颤发作。所有患者均进行常规的电生理检查及标测,记录消融前后心房的电生理参数。根据消融术后随访是否有房颤的发生分为两组进行分析。结果:56例房扑患者全部消融成功,随访14±12(6～60)个月,中位数14个月。消融术后15例有房颤发作,其中3例进展为慢性房颤。15例有房颤发作患者的年龄较无房颤发作的患者大(57.1±13.6岁vs42.3±11.2岁,P<0.05),消融术前和术后的高右房至冠状窦的传导时间延长(分别为98.4±17.1msvs67.8±16.5ms;93.1±18.4msvs70.2±19.7ms;P均<0.05)。多因素Cox回归分析消融前有房颤发作的病史(危险比2.3,95%CI1.425～4.632,P=0.02)和窦性心律下高右房至冠状窦的传导时间超过90ms(危险比1.7,95%CI1.215～3.758,P=0.03)是预测射频消融术后发生房颤的独立的危险因素。结论:典型房扑射频消融术后发生房颤患者心房内传导延迟,并且房内传导延迟是预测射频消融术后发生房颤的重要电生理指标。     

Left Atrial Volume and Adverse Cardiovascular Outcomes in Unselected Patients with and without CKD

Background and objectives

Patients with CKD have increased cardiovascular morbidity and mortality. This study investigated the prognostic value of common clinical echocardiographic parameters.

Design, setting, participants, & measurements

There were 289 unselected consecutive patients who had a transthoracic echocardiogram between January and June 2003. Patients with stage 3 or 4 CKD (n=49) were compared with those with eGFR≥60 ml/min per 1.73 m², n=240). Left ventricular volume, ejection fraction and mass, left atrial volume, and function parameters were measured. The primary endpoint, determined a priori, was a composite of cardiac death, myocardial infarction, and congestive cardiac failure.

Results

Patients were followed for a median 5.6 years. The incidence of the primary endpoint was higher in patients with CKD (29% versus 12%, P=0.001), who were older and had a higher prevalence of hypertension and ischemic heart disease. Indexed left ventricular mass (LVMI) and left atrial volume (LAVI) were higher in patients with CKD. Furthermore, patients with LAVI>32 ml/m² had significantly lower event-free survival than patients with normal (<28 ml/m²) or mildly dilated LAVI (28–32 ml/m²) (P<0.001). Multivariate analysis showed that age (odds ratio [OR], 1.19; 95% confidence interval [95% CI], 1.08 to 1.31; P=0.001) and LVMI (OR, 3.66; 95% CI, 2.47 to 5.41; P<0.001) were independently associated with LAVI>32 ml/m². Multivariate Cox regression analysis demonstrated that CKD (hazard ratio [HR], 1.13; 95% CI, 1.01 to 1.26; P=0.04), hypertension (HR, 2.18; 95% CI, 1.05 to 4.54; P=0.04), and a larger LAVI (HR, 1.35; 95% CI, 1.02 to 1.77; P=0.04) were independent predictors of the primary endpoint.

Conclusions

Patients with CKD were at higher risk for cardiovascular events. LAVI was significantly larger in the CKD group and was a predictor of adverse cardiac events.     

Perioperative Atrial Fibrillation in Noncardiac Surgeries for Malignancies and One-Year Recurrence

BackgroundPerioperative atrial fibrillation (POAF) in noncardiac surgeries is common. However, it is unclear whether such atrial fibrillation (AF) recurs in the long term.MethodsThis study was a prospective, single-center, observational study that included patients who underwent noncardiac surgeries for malignancies. Patients were followed up for 1 year to evaluate the incidence of AF, ischemic stroke, and mortality. An event-triggered recorder was used in patients with POAF. The incidences were compared according to the presence of POAF.ResultsOf 752 consecutive patients, 77 (10.2%) developed POAF and wore an event recorder for 19 (12-30) days. AF and ischemic stroke at 1 year were observed in 24 patients (31.1%) and 2 patients (2.6%) with POAF and 4 patients (0.6%) and 3 patients (0.4%) without POAF, respectively. Of the 24 patients with POAF and AF recurrence, 22 (92%) were asymptomatic. Anticoagulation was prescribed in 67 patients (87%) with POAF. Multivariate Cox regression analysis demonstrated that a higher AF recurrence rate in patients with POAF was associated with hypertension (hazard ratio, 2.79; 95% confidence interval, 1.06-7.38) and serum creatinine level (hazard ratio for 20 μmol/L increase, 2.32; 95% confidence interval, 1.16-4.62).ConclusionsAF recurs in approximately 30% of patients with POAF with malignancy in the subsequent year; most recurrences are asymptomatic.     

P波特征与冠状动脉旁路移植术后心房颤动关系的Meta分析

目的 通过Meta分析综合评价冠状动脉旁路移植术前12导联心电图P波时限、信号平均心电图P波时限及P波离散度与冠状动脉旁路移植术后心房颤动（房颤）的关系.方法 通过进行文献质量评价,应用RevMan 4.3软件进行敏感性和异质性分析后计算综合效应.结果 13篇文献符合纳入标准.Meta分析结果显示,冠状动脉旁路移植术后发生房颤患者的术前12导联心电图P波时限和信号平均心电图P波时限均比未发生房颤患者长.加权均数差（WMD）分别为3.69ms,95%CI 1.93～5.44 12.23ms,95%CI 4.82～19.63.术前P波离散度两组之间差异无统计学意义.术后P波离散度的增加是否是术后房颤的独立预测因子未获得综合效应.结论 术前12导联心电图P波时限和信号平均心电图P波时限延长与术后房颤高发有关,P波离散度的增加与术后房颤的关系有待进一步研究.     

Left atrial dysfunction is a predictor of postcoronary artery bypass atrial fibrillation: association of left atrial strain and strain rate assessed by speckle tracking

Background: Even though atrial fibrillation (AF) is the most common arrhythmia after coronary artery bypass grafting (CABG), its etiology remains poorly understood. Several factors are linked to postoperative AF (POAF), including advanced age and systemic inflammation. However, left atrial (LA) contractile dysfunction has not been evaluated in the perioperative scenario. Aim: To evaluate LA function through strain and strain rate in patients with coronary artery disease undergoing CABG and its correlation with POAF. Methods: We studied 70 patients undergoing CABG in sinus rhythm at the time of surgery. Preoperative echocardiography with evaluation of LA strain and strain rate by speckle tracking was performed. The occurrence of POAF was evaluated by continuous monitoring. Baseline and postoperative C‐reactive protein (CRP) levels were measured to evaluate systemic inflammation. Results: After 1‐week follow‐up 26% of subjects developed AF. LA strain s wave (LASs) and LA strain rate s (LASRs) and a wave (LASRa) were significantly decreased in patients who developed POAF: LASs (10 ± 1% vs. 24 ± 1%, P < 0.001), LASRs (0.6 ± 0.1 sec^–1 vs. 1.2 ± 0.1 sec^?1, P < 0.001), LASRa (?0.6 ± 0.1 sec^–1 vs. –1.8 ± 0.1 sec^?1, P < 0.001). LASRs, LASRa, age, and LA volume were independent predictors of POAF. CRP at baseline was similar irrespective of POAF development. Conclusions: LA dysfunction, evaluated by strain and strain rate is an independent predictor of POAF and contributes to classic risk factors like age and atrial volume. (Echocardiography 2011;28:1104‐1108)     

Prognostic Value of Left Atrial Functional Measures in Heart Failure With Reduced Ejection Fraction

Background

The prognostic value of LA functional measures in heart failure patients with reduced ejection fraction (HFrEF) is unclear. Therefore, this study investigated the prognostic value of left atrial (LA) functional measures such as the left atrial emptying fraction (LAEF) and the minimal LA volume compared with left atrial volume index (LAVI) in HFrEF patients.

Left Atrial Function Determined by Echocardiography Predicts Incident Heart Failure in Patients With STEMI treated by Primary Percutaneous Coronary Intervention

ObjectivesTo assess the comparative effectiveness of left atrial (LA) functional parameters (left atrial emptying fraction (LAEF), left atrial expansion index (LAi) and minimal left atrial volume index (MinLAVI)) with that of LA volume index (LAVI) in predicting heart failure (HF) and death following ST-elevated myocardial infarction (STEMI).BackgroundHF is common following STEMI. Enlarged LA volume as determined by echocardiography predicts adverse outcome following STEMI. However, whether echocardiographic parameters of LA function, such as LAEF, LAi and MinLAVI, are superior to LAVI for predicting prognosis following STEMI is unknown.Methods and ResultsA total of 369 patients with STEMI but without atrial fibrillation or HF who were treated with primary percutaneous coronary intervention were prospectively enrolled in the period between September 2006 and December 2008. Patients underwent echocardiography shortly after STEMI. The maximal and minimal LA volumes were measured using the biplane area-length method. LAVI, MinLAVI (minimal LA volume indexed to body surface area), LAEF ((maximal LA volume–minimal LA volume)/maximal LA volume), and LAi ((maximal LA volume–minimal LA volume)/minimal LA volume) were calculated. The endpoint was a composite consisting of HF or death from any cause. During a median follow-up of 66 months (interquartile range: 50–73 months), 112 patients reached the endpoint (68 HFs, 44 deaths). Following adjustment for clinical, biochemical and echocardiographic variables, only LAEF remained an independent predictor of the composite outcome, whereas LAVI did not (LAEF: HR 1.25, P = 0.043, per 1 SD decrease) (LAVI: HR 1.01, P = 0.91, per 1 SD increase).ConclusionIn patients with STEMI who were treated with primary percutaneous coronary intervention, LAEF, as measured by echocardiography shortly after infarction, was superior to LAVI in predicting incident HF and death.     

Statin therapy in the primary prevention of early atrial fibrillation after coronary artery bypass grafting

ObjectiveAssessment of the role of statin therapy in the prevention of postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG) in patients without prior atrial fibrillation.MethodsA retrospective analysis of 206 patients, aged 57.2 ± 7.9 years (mean ± SD), who underwent isolated CABG is carried out. All patients are divided into two groups. The first group (nSt-patients) includes the patients who did not receive statin therapy prior to CABG (n = 82). The second group (St-patients) includes the patients who received statin therapy prior to CABG (n = 124). Both groups received the statin therapy from the first day after CABG. The risk of occurrence of POAF is evaluated using the Cox-regression model.ResultsThe rate of POAF was 25.6% in nSt-patients and 6.5% in St-patients (P = 0.020). On the 4th day after CABG, white blood cells (WBC) count was 11.0 (9.0, 13.0) × 10⁹/mL (medians with inter-quartile ranges) in nSt-patients and 9.0 (7.6, 10.2) × 10⁹/mL in St-patients (P < 0.001). The peak WBC numbers occurred on the day of POAF onset. The Cox-regression analysis shows that only two factors (statin therapy and number of grafts) had significant influence on the POAF onset. Odds ratio of POAF event prediction by statin therapy was 0.20 (95%CI: 0.08–0.51), P < 0.001. Each subsequent graft increased the risk of POAF in 2.1 times.ConclusionStatin therapy carried out prior to the CABG is an effective approach to primary prevention of POAF in early postoperative period. Statin therapy after CABG in nSt-patients does not give prophylactic effect observed in St-patients.     

Calcium-Induced Autonomic Denervation in Patients With Post-Operative Atrial Fibrillation

BackgroundPost-operative atrial fibrillation (POAF) is associated with worse long-term cardiovascular outcomes.ObjectivesThis study hypothesized that injecting calcium chloride (CaCl₂) into the major atrial ganglionated plexi (GPs) during isolated coronary artery bypass grafting (CABG) can reduce the incidence of POAF by calcium-induced autonomic neurotoxicity.MethodsThis proof-of-concept study randomized 200 patients undergoing isolated, off-pump CABG to CaCl₂ (n = 100) or sodium chloride (sham, n = 100) injection. Two milliliters of CaCl₂ (5%) or sodium chloride (0.9%) was injected into the 4 major atrial GPs during CABG. All patients received 7-day continuous telemetry and Holter monitoring. The primary outcome was incidence of POAF (≥30 s) in 7 days. Secondary outcomes included length of hospitalization, POAF burden, average ventricular rate during AF, plasma level of inflammatory markers, and actionable antiarrhythmic therapy to treat POAF.ResultsThe POAF incidence was reduced from 36% to 15% (hazard ratio: 0.366; 95% confidence interval: 0.211 to 0.635; p = 0.001). Length of hospitalization did not differ between the 2 groups. POAF burden (first 7 post-operative days), the use of amiodarone or esmolol, and the incidence of atrial couplets and nonsustained atrial tachyarrhythmias were significantly reduced in the CaCl₂ group. Heart rate variability data showed a decrease in both high-frequency and low-frequency power in the CaCl₂ group with a preserved low-frequency/high-frequency ratio, suggesting that the sympathetic/parasympathetic balance was not perturbed by CaCl₂ injection.ConclusionsInjection of CaCl₂ into the 4 major atrial GPs reduced the POAF hazard by 63%. Inhibition of GP function by Ca-mediated neurotoxicity may underlie the therapeutic effect. (Calcium Autonomic Denervation Prevents Postoperative Atrial Fibrillation; ChiCTR1800019276)     

Postoperative Atrial Fibrillation or Flutter Following Transcatheter or Surgical Aortic Valve Replacement: PARTNER 3 Trial

ObjectivesThe aim of this study was to assess the incidence and prognostic impact of early and late postoperative atrial fibrillation or flutter (POAF) in patients with severe aortic stenosis (AS) treated with transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR).BackgroundThere is an ongoing controversy regarding the incidence, recurrence rate, and prognostic impact of early (in-hospital) POAF and late (postdischarge) POAF in patients with AS undergoing TAVR or SAVR.MethodsIn the PARTNER (Placement of Aortic Transcatheter Valve) 3 trial, patients with severe AS at low surgical risk were randomized to TAVR or SAVR. Analyses were performed in the as-treated population excluding patients with preexistent atrial fibrillation or flutter.ResultsAmong 781 patients included in the analysis, early POAF occurred in 152 (19.5%) (18 of 415 [4.3%] and 134 of 366 [36.6%] following TAVR and SAVR, respectively). Following discharge, 58 new or recurrent late POAF events occurred within 1 year following the index procedure in 55 of 781 patients (7.0%). Early POAF was not an independent predictor of late POAF following discharge (odds ratio: 1.04; 95% CI: 0.52-2.08; P = 0.90). Following adjustment, early POAF was not an independent predictor of the composite outcome of death, stroke, or rehospitalization (hazard ratio: 1.10; 95% CI: 0.64-1.92; P = 0.72), whereas late POAF was associated with an increased adjusted risk for the composite outcome (hazard ratio: 8.90; 95% CI: 5.02-15.74; P < 0.0001), irrespective of treatment modality.ConclusionsIn the PARTNER 3 trial, early POAF was more frequent following SAVR compared with TAVR. Late POAF, but not early POAF, was significantly associated with worse outcomes at 2 years, irrespective of treatment modality.     

Long‐Term Outcome of Catheter Ablation in Patients with Atrial Fibrillation Originating from Nonpulmonary Vein Ectopy

Long‐Term Outcome of NPV AF Ablation . Introduction: Data regarding the long‐term outcome of catheter ablation in patients with nonpulmonary vein (NPV) ectopy initiating atrial fibrillation (AF) are limited. We aimed to evaluate the long‐term result of patients with AF who had NPV triggers and underwent catheter ablation. Methods and Results: The study included 660 consecutive patients (age 54 ± 11 years old, 477 males) who had undergone catheter ablation for AF. Group 1 consisted of 132 patients with AF initiating from the NPV, and group 2 consisted of 528 patients with AF initiating from pulmonary vein (PV) triggers only. Patients from Group 1 were younger than those from Group 2 (51 ± 12 years old vs 54 ± 11 years old, P = 0.001) and were more likely to be females (34.4% vs 25.8%, P = 0.049). The incidences of nonparoxysmal AF (36.4% vs 16.3%, P < 0.001) and right atrial (RA) enlargement (31.3% vs 19%, P = 0.004) were higher, and the biatrial substrates were worse in Group 1 than those in Group 2 (left atrial voltage 1.5 ± 0.7 mV vs 1.9 ± 0.7 mV, P < 0.001, RA voltage 1.6 ± 0.5 mV vs 1.8 ± 0.6 mV, P = 0.014). During a follow‐up period of 46 ± 23 months, there was a higher AF recurrence rate in Group 1 than in Group 2 (57.6% vs 38.8%, P < 0.001). The independent predictors of AF recurrence were NPV trigger (P < 0.001, HR 2, 95% CI 1.4–2.85), nonparoxysmal AF (P = 0.021, HR 1.55, 95% CI 1.07–2.24), larger left atrial diameter (P = 0.002, HR 1.04, 95% CI 1.02–1.07) and worse left atrial substrate (P = 0.028, HR 1.3, 95% CI 1.03–1.64). Conclusion: Compared to AF originating from the PV alone, AF originating from the NPV ectopy showed a worse outcome. (J Cardiovasc Electrophysiol, Vol. 24, pp. 250‐258, March 2013)     

The impact of left atrial pressure on filtered P-wave duration in patients with atrial fibrillation

The cause of prolonged filtered P-wave duration (FPD) remains unclear in atrial fibrillation (AF) patients with normal left atrial size. We investigated whether FPD is associated with left atrial pressure (LAP) in AF patients without prominent LA enlargement. This study included 80 patients (48 men, age 65 ± 9 years, 25 persistent AF) with non-valvular AF who underwent catheter ablation (CA) for AF. LAP was measured in sinus rhythm during CA and signal-averaged electrocardiogram was recorded after CA. We retrospectively assessed the clinical and echocardiographic variables. Prolonged FPD was defined as FPD > 120 ms. Prolonged FPD (FPD > 120 ms) was detected in 23/80 patients (29 %). According to univariate analysis, higher mean LAP (14.9 ± 4.4 vs. 10.8 ± 3.5 mmHg, p < 0.0001), higher prevalence of persistent arrhythmia, higher BNP, larger LAD, higher E wave, and lower LVEF were associated with Prolonged FPD. According to multivariate analysis, higher mean LAP was the only factor associated with Prolonged FPD (p = 0.0058, OR 1.256 for each 1 mmHg increase in mean LAP, 95 % CI 1.068–1.476). Moreover, a significant correlation was observed between FPD and mean LAP (r = 0.503, p < 0.0001). Prolonged FPD is associated with high LAP in AF patients without prominent left atrial enlargement. Pressure overload of the left atria might cause slowing of atrial electrical activation.     

Left Atrial Strain Assessed by Speckle Tracking Imaging Is Related to New-Onset Atrial Fibrillation After Coronary Artery Bypass Grafting

Background

Left atrial (LA) dysfunction was recently proposed as an important factor in the development of postoperative atrial fibrillation (POAF). LA strain analysis by 2-dimensional (2D) speckle tracking imaging is emerging as a new tool to evaluate LA function. We aimed to evaluate the correlation of LA dysfunction assessed by 2D speckle tracking imaging with the occurrence of POAF after coronary artery bypass grafting (CABG).

Methods

In this study, 53 patients (mean age 66 ± 9 years) undergoing elective isolated CABG were enrolled. Conventional transthoracic echocardiography and 2D speckle tracking strain analysis were performed before surgery. POAF was detected with continuous electrocardiography monitoring throughout hospitalization (mean duration 17 ± 10 days).

Results

POAF occurred in 13 of 53 patients (24%). Patients with POAF were significantly older than patients with normal sinus rhythm after surgery (71 ± 5 vs 64 ± 10 years, P = 0.026). Compared with patients with normal sinus rhythm, patients with POAF had a significantly larger LA volume index (32.6 ± 5.1 vs 27.3 ± 7.2 mL/m², P = 0.018), lower value of LA global strain (25.4 ± 10.4 vs 36.8 ± 7.6%, P = 0.001), and strain rate (1.2 ± 0.6 vs 1.6 ± 0.8 seconds, P = 0.024). By multivariate logistic regression analysis, only LA global strain (odds ratio, 1.12; 95% confidence interval, 1.00-1.24; P = 0.040) was an independent predictor of POAF after CABG.

Conclusions

Preoperative LA global strain measured by 2D speckle tracking strain analysis is associated with the development of POAF after CABG.     

The effect of VVI pacing on P-wave dispersion in patients with dual-chamber pacemakers

The incidence of atrial fibrillation is higher in patients with VVI pacing mode than DDD pacing mode, but the likely mechanism is not clearly understood. We aimed to evaluate whether short-term VVI pacing increases inhomogeneous atrial conduction by using P-wave dispersion. Forty-seven patients (32 men, 15 women, mean age 54 ± 13 years) with DDD pacemakers were enrolled in this study. Twelve-lead surface ECGs were obtained in all patients during VDD pacing after an observation period of 1 week. The mode was then changed to VVI and 12 lead surface ECGs were obtained after another 1-week observation period. P-wave durations were calculated in all 12 leads in both VDD and VVI pacing modes. The difference between the maximum and the minimum P-wave duration was defined as the P-wave dispersion (PWD = P_max − P_min). P-wave maximum duration (P_max) calculated in VVI pacing mode was significantly longer than in VDD pacing mode (128 ± 19 vs 113 ± 16 ms, P < 0.001). There was no significant difference in the P-wave minimum durations (80 ± 13 ms vs 79 ± 12 ms, P = 0.7) between VVI pacing and VDD pacing. The P-wave dispersion value was higher in the VVI pacing mode than in the VDD pacing mode (48 ± 8 ms vs 34 ± 7 ms, P < 0.001). Short-term VVI pacing induces prolongation of P_max and results in increased P-wave dispersion, which might be responsible for the development of atrial fibrillation more frequently in these patients than in those with the VDD pacing mode.     

预激综合征患者发生阵发性心房颤动机制的探讨

目的通过分析预激综合征患者旁道的电生理特性以及消融旁道后P波离散度(Pd)的计算,探讨预激综合征发生阵发性心房颤动(简称房颤)的机制。方法分析预激综合征合并旁道介导的阵发性心动过速患者127例。根据既往有无阵发性房颤(PAF)发作将患者分为PAF组(23例)和无PAF组(NPAF,104例)2组进行分析。电生理检查测定旁道的前传和逆传不应期。消融成功术后24h描记12导联心电图测量P波最大时限(Pmax)、P波最小时限(Pmin),计算Pd。结果消融前PAF组旁道前传和逆传不应期较NPAF组短(前传:265.3±42.5msvs331.4±38.7ms;逆传:255.8±46.7msvs317.5±31.7ms;P均<0.05)。消融术后心电图Pmax和PdPAF组显著长于NPAF组(Pmax:135.2±12.5msvs120.4±8.7ms;Pd:51.6±10.3msvs32.7±6.7ms;P均<0.05)。结论旁道有效不应期缩短和窦性激动在心房内的非均质传导在预激综合征患者房颤发生中可能起重要作用。     

Atrial Remodeling Following Catheter-Based Renal Denervation Occurs in a Blood Pressure– and Heart Rate–Independent Manner

ObjectivesThis study sought to investigate left atrial (LA) remodeling in relation to blood pressure (BP) and heart rate (HR) after renal sympathetic denervation (RDN).BackgroundIn addition to reducing BP and HR in certain patients with hypertension, RDN can decrease left ventricular (LV) mass and ameliorate LV diastolic dysfunction.MethodsBefore and 6 months after RDN, BP, HR, LV mass, left atrial volume index (LAVI), diastolic function (echocardiography), and premature atrial contractions (PAC) (Holter electrocardiogram) were assessed in 66 patients with resistant hypertension.ResultsRDN reduced office BP by 21.6 ± 3.0/10.1 ± 2.0 mm Hg (p < 0.001), and HR by 8.0 ± 1.3 beats/min (p < 0.001). At baseline, LA size correlated with LV mass, diastolic function, and pro-brain natriuretic peptide, but not with BP or HR. Six months after RDN, LAVI was reduced by 4.0 ± 0.7 ml/kg/m² (p < 0.001). LA size decrease was stronger when LAVI at baseline was higher. In contrast, the decrease in LAVI was not dependent on LV mass or diastolic function (E/E′ or E/A) at baseline. Furthermore, LAVI decreased without relation to decrease in systolic BP or HR. Additionally, occurrence of PAC (median of >153 PAC/24 h) was reduced (to 68 PAC/24 h) by RDN, independently of changes in LA size.ConclusionsIn patients with resistant hypertension, LA volume and occurrence of PAC decreased 6 months after RDN. This decrease was independent of BP and HR at baseline or the reduction in BP and HR reached by renal denervation. These data suggest that there is a direct, partly BP-independent effect of RDN on cardiac remodeling and occurrence of premature atrial contractions.