Predictive value of normal left atrial volume in stress echocardiography.

OBJECTIVES: Our objective was to evaluate whether normal left atrial volume index (LAVI) is a predictor of a normal stress echocardiogram and thus a predictor of low ischemic risk. BACKGROUND: Left atrial enlargement is closely related to the chronicity and intensity of the burden of increased ventricular filling pressure. Typically ischemic heart disease (IHD) has a long period of subclinical dysfunction. Increased filling pressure, reflected by enlarged LAVI, is hypothesized to mirror the burden of subclinical and overt IHD. We hypothesized that a normal LAVI might also be useful in predicting low IHD risk. METHODS: One hundred eighty randomly selected patients (mean age, 63 +/- 15 years; 53% men) underwent outpatient exercise or dobutamine stress echocardiography for known or suspected coronary artery disease. Left atrial volume index was measured retrospectively with the biplane area-length method. The stress echocardiogram was interpreted as abnormal if wall motion abnormalities (WMAs) were noted at rest and/or with stress. RESULTS: Left atrial volume index was categorized as < or =28 ml/m2 (normal), 28.1 to 32 ml/m2, 32.1 to 36 ml/m2, and >36 ml/m2. Abnormal stress echocardiography was identified in 57 patients (31.7%). The percentage of abnormal stress echocardiograms in each LAVI category was 5.7%, 21.9%, 38.7%, and 54.7%, respectively. The negative predictive value for LAVI < or =28 ml/m2 was 94.3%. CONCLUSIONS: Normal resting LAVI (< or =28 ml/m2) was strongly predictive of a normal stress echocardiogram. Left atrial volume index might be a simple means of identifying patients with low ischemic risk and should be further evaluated as a complement to the assessment of ischemic risk.     

Assessment of echocardiographic left atrial size: accuracy of M-mode and two-dimensional methods and prediction of diastolic dysfunction

Background: Despite the American Society of Echocardiography recommendation to use left atrial volume indexed for body surface area (LAVI) for quantification of left atrial size, a variety of methods are used in clinical practice. Our objectives were to evaluate the accuracy of M‐mode and two‐dimensional (2D) echocardiographic LA size estimates to LAVI and to determine their ability to predict left ventricular diastolic dysfunction. Methods: In 150 consecutive patients, LA diameter (LAD), LA diameter indexed for body surface area (LADI), LA area in the apical two‐ and four‐chamber views (LAA 2c and LAA 4c), biplane area–length LA volume (LAV), and LAVI were obtained. The accuracy of these methods to quantify LA enlargement by LAVI, correlation with clinical parameters, and ability to act as a surrogate for diastolic dysfunction were determined using Pearson correlation coefficients along with univariate and multiple logistic analysis. Results: The true degree of LA size (with LAVI as standard) was identified by LAD in 45%, LADI in 42%, LAA 4c in 43%, and LAA 2c in 41%. All methods showed positive correlation with age, E/E′, mitral regurgitation, and right atrial size and negative correlation with ejection fraction. LAVI was the strongest method to predict any (c = 0.655, P = 0.012) or moderate–severe (P = 0.856 and P < 0.001) diastolic dysfunction. All methods have greater capacity to identify moderate or severe diastolic dysfunction than any degree of diastolic dysfunction alone. Conclusions: One‐dimensional and 2D methods inaccurately quantify LA size and are inferior to LAVI to predict diastolic dysfunction. (Echocardiography 2012;29:379‐384)     

三维超声心动图及斑点追踪成像评价左心房不同构型阵发性房颤患者左心房功能的临床研究

目的应用实时三维超声心动图(3D-RTE)及二维斑点追踪成像(2D-STI)评价左心房不同构型的阵发性房颤患者(PAF)左心房结构和功能。方法入选2017年1月至2018年12月于解放军总医院第七医学中心收治的阵发性房颤患者98例。根据二维超声左心房容积指数(LAVI-2D)将房颤患者分为左心房容积正常组(LAN组,LAVI<34 ml/m^2,50例)和左心房容积扩大组(LAE组,LAVI≥34 ml/m^2,48例)。选择同期38例临床资料匹配者为对照组。实时三维超声心动图测定左心房最大容积(LAVmax),左心房最小容积(LAVmin),左心房容积指数(LAVI-3D)和左心房总排空分数(LATEF)。斑点追踪显像获取左心房纵向时间-应变曲线,记录收缩期平均应变(SSL)和各时相平均应变率(mSRs、mSRe、mSRa)。结果PAF患者LAVI平均水平高于对照组,且LAE组LAVI水平高于LAN组,LAVI-3D测量值较LAVI-2D测量值高(P均<0.05)。PAF患者LATEF平均水平低于对照组,且LAE组LATEF水平小于LAN组(P均<0.05)。与对照组比较,PAF患者mSSL、mSRs、mSRe和mSRa水平均降低,LAE组mSSL、mSRs、mSRe和mSRa水平小于LAN组,差异有统计学意义(P均<0.05)。结论三维超声心动图较二维测量左心房容积大,能更准确评估左心房容积。左心房容积无明显增大房颤患者,已出现左心房功能减低。左心房扩大者应变指标进一步下降,左心房功能减低明显。三维超声心动图及斑点追踪成像能早期评价房颤患者左心房功能异常。     

Increased left atrial volume index is an independent predictor of raised serum natriuretic peptide in patients with suspected heart failure but normal left ventricular ejection fraction: Implication for diagnosis of diastolic heart failure

BACKGROUND: Left atrial volume index (LAVI) is increasingly recognised as a relatively load-independent marker of left ventricular (LV) filling pressures. We assessed the capacity of LAVI to predict LV diastolic dysfunction in comparison with N-terminal pro B-type natriuretic peptide (NTproBNP) in patients with suspected heart failure and a normal ejection fraction (EF). METHODS: 137 patients with suspected heart failure (HF), referred from the community for echocardiography, prospectively underwent Doppler echocardiography, LAVI and NTproBNP estimation. Raised LAVI and reduced LV systolic function were defined as >26 ml/m2 and LV EF <50% respectively. RESULTS: Of 137 patients, 21 were excluded (2 with significant mitral valve disease and 19 with atrial fibrillation). Of the remaining 116 subjects, 92 showed normal LV systolic function. The univariate predictors of serum log NTproBNP were age (p < 0.001), LA dimension (p = 0.001), LAVI (p < 0.001), A wave (p = 0.001), E:A (p = 0.07) and septal wall thickness (p = 0.004). However on multivariate analysis, LAVI was found to be the most consistent and significant predictor of NTproBNP. The area under the curve of the receiver operating characteristic (ROC) curve for NTproBNP in detecting patients with LVEF > or = 50% and LAVI >26 ml/m2 was 0.81 (p < 0.0001) and for patients with LAVI > 26 ml/m2 with and without LVEF > or = 50% was 0.82 (p < 0.0001). CONCLUSION: This data confirms that LAVI on resting echocardiography, specifically in patients with suspected HF and normal LV systolic function is a powerful independent predictor of LV diastolic dysfunction as predicted by serum NTproBNP. In a population with a high suspicion of diastolic heart failure, LAVI may significantly contribute to diagnostic precision.     

Usefulness of left atrial volume index to predict heart failure hospitalization and mortality in ambulatory patients with coronary heart disease and comparison to left ventricular ejection fraction (from the Heart and Soul Study)

The predictive value of left atrial (LA) dilatation in ambulatory adults with coronary artery disease is not known. It was hypothesized that echocardiographic LA volume index (LAVI) predicts heart failure (HF) hospitalization and mortality with similar statistical power as left ventricular ejection fraction (LVEF) in ambulatory adults with coronary artery disease. We measured LAVI in 935 adults without atrial fibrillation, atrial flutter, or significant mitral valve disease in the Heart and Soul Study. LAVI was calculated using the biplane method of disks. Outcomes included HF hospitalization and mortality. Logistic regression odds ratios (ORs) were calculated and adjusted for age, demographics, medical history, left ventricular mass, diastolic function, and LVEF. Mean LAVI was 32 +/- 11 ml/m2, and mean LVEF was 62 +/- 10%. Sixty-six patients (7%) had LAVI >50 ml/m2. There were 108 HF hospitalizations and 180 deaths at 4.3 years of follow-up. C statistics calculated as the area under the receiver-operator characteristic curve were the same (0.60) for LAVI and LVEF in predicting mortality. The unadjusted OR for HF hospitalization was 4.4 for LAVI >50 ml/m2 and 5.3 for LVEF <45% (p <0.001). In those with normal LVEF, the ORs for LAVI >50 ml/m2 were 5.2 for HF hospitalization (p <0.0001) and 2.5 for mortality (p = 0.006). After multivariate adjustment, LAVI >50 ml/m2 was predictive of HF hospitalization (OR 2.4, p = 0.02), and LAVI >40 ml/m2 was predictive of mortality (OR 1.9, p = 0.005). In conclusion, LAVI had similar predictability as LVEF for HF hospitalization and mortality in ambulatory adults with coronary artery disease.     

肥胖和高血压与左心房增大关联度的比较研究

目的 探讨高血压、肥胖对左心房大小的影响.方法 按是否患高血压或肥胖将383例受试者分为非高血压非肥胖组(NS组,n=95)、单纯高血压组(HT组,n=97)、单纯肥胖组(OB组,,n =98)及高血压合并肥胖组(HT+ OB组,n=93),比较4组临床资料、超声心动图指标及左心房大小.结果 (1)4组左心房容积指数(LAVI)由高到低分别是:HT+OB组(28.07±6.63)ml/m＞ OB组(24.61±4.89) ml/m＞ HT组(22.73±5.16) ml/m＞ NS组(19.18±4.82)ml/m(P ＜0.05);校正年龄、性别、心率、空腹血糖、总胆固醇、甘油三酯、高密度脂蛋白胆固醇后:4组之间LAVI比较仍有显著性差异(P＜0.05).(2) Pearson相关分析表明,体质指数(BMI)与LAVI相关性明显大于收缩压、舒张压(r值分别为0.505、0.240、0.209,P＜0.001),校正其他影响因素后,BMI与LAVI之间仍有显著相关性(β=0.411,P＜0.001),而收缩压、舒张压与之无显著相关;BMI每增加1个单位,左心房内径增加0.052 cm,左心房容积增加1.053 ml,LAVI增加0.710 ml/m.结论 肥胖较高血压引起左心房增大更加明显,肥胖和高血压对左心房增大有协同作用.     

Left atrial appendage anatomy and function: short term response to sustained atrial fibrillation

OBJECTIVE—To determine whether there is significant atrial or atrial appendage enlargement or functional remodelling as a result of one to two months of sustained atrial fibrillation, a duration similar to that experienced by patients undergoing warfarin anticoagulation before elective cardioversion.
METHODS—To test the hypothesis that left atrial and left atrial appendage enlargement develop as a result of short term atrial fibrillation, serial anatomical and functional indices were measured using transoesophageal echocardiography (TOE) in 20 patients with recent onset atrial fibrillation (14 men, six women; mean (SEM) age 67 (2) years). Serial TOE was performed 2.5 months apart in patients with sustained atrial fibrillation.
RESULTS—There was no significant change in left atrial area (23.7 cm² to 24.1 cm², p = 0.98); length (5.7 cm to 5.7 cm, p = 0.48); width (5.2 cm to 5.2 cm, p = 0.65); volume (83 cm³ to 87 cm³, p = 0.51) or left atrial appendage area (7.9 cm² to 8.1 cm², p = 0.89); length (4.6 cm to 4.5 cm, p = 0.8); or width (2.5 to 2.4 cm, p = 0.87). Peak left atrial appendage velocity ejection (0.2 m/s to 0.2 m/s, p = 0.57), and presence of severe spontaneous echo contrast in the left atrial appendage (n = 15 (75%) to n = 13 (72%)) were also not significantly different. There was no correlation between changes in left atrial or left atrial appendage dimensions.
CONCLUSIONS—In the setting of sustained atrial fibrillation, significant left atrial and left atrial appendage functional and anatomical remodelling do not occur with atrial fibrillation of a duration similar to that used for conservative anticoagulation in preparation for cardioversion.


Keywords: atrial fibrillation; left atrial appendage; remodelling     

冷冻球囊消融与射频消融对阵发性心房颤动患者心房重构的影响

目的:比较冷冻球囊消融(CBA)与射频消融(RFA)对阵发性心房颤动(房颤)患者心房重构的影响.方法:本研究选取在2014年5月-2017年5月于郑州大学第一附属医院因阵发性房颤行CBA或RFA治疗的患者.所有患者均于术前、术后半年、1年、2年和3年时行12导联心电图或24 h动态心电图和超声心动图检查.左心房电重构通...     

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。     

Left atrial volume as an index of left atrial size: a population-based study

OBJECTIVES: We studied left atrial volume (LAV) as an index of atrial size. BACKGROUND: Increased left atrial dimension (LAD) measured by M-mode echocardiography is a risk factor for atrial fibrillation, stroke, and death. METHODS: A random sample of residents of Olmsted County, Minnesota, age > or =45 years (n = 2,042) underwent Doppler echocardiography with assessment of LAD and LAV. A subgroup of the population (n = 767) with no cardiovascular disease and normal systolic and diastolic function was used to develop reference ranges for LAD and LAV. In the total population, the prevalence of left atrial enlargement and the association between cardiovascular disease and left atrial size as determined by both indexes were assessed. RESULTS: In the normal subgroup, both indexes were associated with gender and body size, thus models controlling for body size were used to determine gender-specific reference ranges for LAD and LAV. In the total population, left atrial enlargement was common, with a prevalence of 18% (men) and 12% (women) using LAD/body surface area (BSA) and of 16% (men and women) using LAV/BSA. The agreement between the indexes was only fair (kappa = 0.53). Adjusting for age and gender, LAV/BSA was more strongly associated with the presence of cardiovascular diseases than LAD/BSA. CONCLUSIONS: We described a simple technique of measuring LAV, examined methods for indexing LAV, and described its normal range in a large, healthy reference cohort. Further, we find that in the community, left atrial enlargement is common and reflects the burden of cardiovascular disease.     

Long-term prognostic significance of left atrial volume in acute myocardial infarction

OBJECTIVES: The aim of this study was to evaluate the significance of increased left atrial (LA) volume determined within the first 48 h of admission as a long-term predictor of outcome in patients with acute myocardial infarction (MI). BACKGROUND: The LA volume reflects left ventricular (LV) diastolic properties. Whereas other LV Doppler diastolic characteristics are influenced by acute changes in LV function, LA volume is stable and reflects diastolic properties before MI. METHODS: Clinical and echocardiographic parameters were prospectively collected in 395 consecutive patients with acute MI. Patients with LA volume index (LAVI) >32 ml/m(2) (normal + 2 standard deviations) were compared with those with LAVI <==32 ml/m(2). Independent clinical and echocardiographic prognostic risk factors for five years' mortality were determined by the Cox proportional hazard model. RESULTS: Left atrial volume index >32 ml/m(2) was found in 63 patients (19%) who had a higher incidence of congestive heart failure on admission (24% vs. 12%, p < 0.01), a higher incidence of mitral regurgitation, increased LV dimensions, and reduced LV ejection fraction when compared with patients with LAVI <==32 ml/m(2). Their five-year mortality rate was 34.5% versus 14.2% (p < 0.001). Significant independent risk predictors of five years' mortality were age (10 years) (odds ratio [OR] 1.45; 95% confidence interval [CI]1.14 to 1.86), Killip class >/=2 on admission (OR 2.30; 95% CI 1.29 to 4.09), LAVI >32 ml/m(2) (OR 2.22; 95% CI 1.25 to 3.96), diabetes (OR 1.94; 95% CI 1.15 to 3.28), and LV restrictive filling pattern (OR 1.89; 95% CI 1.09 to 3.31). CONCLUSIONS: In patients with acute MI, increased LA volume, determined within the first 48 h of admission, is an independent predictor of five-year mortality with incremental prognostic information to clinical and echocardiographic data.     

原发性高血压患者左心房扩大及其影响因素

目的　分析 12 0例原发性高血压患者左心房大小及其影响因素。方法　原发性高血压患者 12 0例 ,男 5 9例 ,女 6 1例 ,年龄 33～ 78岁。全部患者分为两组 ,年龄≥ 6 0岁为老年组 (6 0例 ) ,年龄 <6 0岁为非老年组 (6 0例 )。每组根据心脏超声分为左心室肥厚和无左心室肥厚两个亚组。左心房内径大于 4cm为左心房扩大 ,面积 长度法左心室重量指数男性 >89g m2 ,女性 >77g m2 为左心室肥厚。结果　非老年组 4 3%、老年组 73%合并左心室肥厚 ;非老年组 14例 (2 3% )、老年组 2 2例 (37% )合并左心房扩大 ;37%患者左心房扩大和左心室肥厚同时并存 ,2 0 %患者仅有左心房扩大 ;两组左心房扩大者共 36例 ,其中老年组合并左心室肥厚占 5 0 % (18 36 ) ,非老年组合并左心室肥厚占 2 2 % (8 36 ) ;多因素分析提示超重、血压水平与左心房扩大无显著相关性 ,年龄和左心室重量指数同左心房扩大显著相关。结论　年龄与左心室肥厚是原发性高血压左心房扩大的重要影响因素。     

左心房容积指数在评价急性心肌梗死病例预后中的价值

目的探讨左心房容积指数(LAVI)与急性心肌梗死(AMI)预后之间的关系。方法选取收治的AMI病例312例,于急性期行超声心动图检查,测左心房容积、左心室的收缩和舒张功能,左心房容积通过体表面积来校正,将观察者按LAVI分为两组,即LAVI>30ml/m2共168例(占54%)和≤30ml/m2共144例(占46%)两组,自病例入院开始观察,若病例死亡观察结束。结果在平均36个月(0~60月)的观察随访过程中,共有50例死亡,其中LAVI≤30ml/m2死亡14例,LAVI>30ml/m2者死亡36例,P<0.001。LAVI是AMI病例预后的一个重要和独立危险因素(LAVI每增加1ml/m2,相对危险度为1.04,95%可信区间为1.03~1.06,P<0.001)。结论LAVI增大是AMI病例预后的一个独立危险因素,能够提供关于心肌梗死病例预后的信息,它和射血分数一起可以大大提高对心肌梗死病例预后的预测。     

Identification of factors associated with progression of left atrial enlargement in patients with atrial fibrillation

Left atrial (LA) enlargement frequently occurs in atrial fibrillation (AF) patients, and this enlargement is associated with the development of heart failure, thromboembolism, or atrial functional mitral regurgitation (AFMR). AF patients can develop LA enlargement over time, but its progression depends on the individual. So far, the factors that cause progressive LA enlargement in AF patients have thus not been elucidated, so that the aim of this study was to identify the factors associated with the progression of LA enlargement in AF patients. We studied 100 patients with persistent or permanent AF (aged: 67 ± 2 years, 40 females). Echocardiography was performed at baseline and 12 (5–30) months after follow-up. LA size was evaluated as the LA volume index which was calculated with the biplane modified Simpson's method from apical four-and two-chamber views, and then normalized to the body surface area (LAVI). The deterioration of AFMR after follow-up was defined as a deterioration in severity of mitral regurgitation (MR) by a grade of 1 or more. Multivariate regression analysis demonstrated that hypertension (p = .03) was an independently associated parameter of progressive LA enlargement, as was baseline LAVI. In addition, the Kaplan–Meier curve indicated that patients with hypertension tended to show greater deterioration of AFMR after follow-up than those without hypertension (log-rank p = .08). Hypertension proved to be strongly associated with progression of LA enlargement over time in patients with AF. Our findings provide new insights for better management of patients with AF to prevent the development of AFMR.     

Significance of echocardiographic left atrial enlargement in aortic stenosis

This study investigated the significance of echocardiographic left atrial enlargement as measured by the left atrial dimension corrected for body surface area in 24 patients with pure aortic stenosis established by cardiac catheterization. Echocardiographic evidence of left atrial enlargement occurred in 11 of 15 patients (73%) with an aortic valve area below 0.8 cm2 and in none of nine patients (0%) with an aortic valve area above 0.8 cm2, p less than 0.0025. All 11 patients (100%) with an enlarged left atrial dimension had an increased diastolic left ventricular dimension, whereas 1 of 13 patients (8%) with a normal left atrial dimension had an increased diastolic left ventricular dimension, p less than 0.00001. The 11 patients (100%) with an enlarged left atrial dimension had increased posterior left ventricular wall thickness, whereas 2 of 13 patients (13%) with a normal left atrial dimension had increased posterior left ventricular wall thickness (p less than 0.0005). These data lead one to conclude that in patients with pure aortic stenosis, echocardiographic evidence of left atrial enlargement as measured by an increased left atrial dimension corrected for body surface area should lead one to suspect severe aortic stenosis.     

The interplay between haemodynamic load, brain natriuretic peptide and left atrial size in the early stages of essential hypertension

OBJECTIVE: Left atrial (LA) enlargement is an index of adverse cardiovascular events. We sought to investigate any possible correlation between haemodynamic load, neurohumoral factors and LA size in the early stages of essential hypertension. METHODS: We studied 94 consecutive middle-aged subjects, with newly diagnosed stage I-II essential hypertension without left ventricular (LV) hypertrophy and 34 age and sex-matched normotensive individuals. Ambulatory blood pressure (BP) monitoring, plasma levels of brain natriuretic peptide (BNP), metabolic profile and left atrial volume index (LAVI), an echocardiographic measurement of LA volume indexed for the body surface area, constituted the work-up of all subjects. RESULTS: Hypertensive compared with normotensive subjects had significantly increased office and ambulatory systolic and diastolic BP (P < 0.0001 for all cases) as well as body mass index and waist-to-hip ratio (P < 0.05 for both cases). BNP levels were greater in hypertensive compared with normotensive subjects but were not statistically significant (20.4 versus 17.1 pg/ml, P = NS). Hypertensive compared with normotensive subjects also had significantly increased LV mass index (105 versus 84 g/m, P < 0.0001), LA diameter (39 versus 36 mm, P < 0.0001), and LAVI (22 versus 19 ml/m, P < 0.05). In the hypertensive population, LAVI exhibited significant positive relationships with office systolic BP, ambulatory pulse pressure, LV mass index and BNP. In multiple linear regression analysis only LV mass index and BNP were significantly associated with LAVI (beta = 0.298, P = 0.030 and beta = 0.322, P = 0.009, respectively). CONCLUSIONS: Increased LAVI, closely associated with LV mass index and BNP, was still found in the early stages of essential hypertension. However, the clinical significance of these findings remains to be elucidated in future studies.     

Identification of good responders to rhythm control of paroxysmal and persistent atrial fibrillation by transthoracic and transesophageal echocardiography

BACKGROUND: Identification of good responders to rhythm control in the management of atrial fibrillation (AF) is worthwhile in terms of increasing hemodynamic benefit and decreasing the likelihood of unstable anticoagulation even after the Atrial Fibrillation Follow-Up Investigation of Rhythm Management. METHODS: We tested the hypothesis that atrial substrate determines the risk of recurrence on rhythm control both in patients with paroxysmal AF (PAF) and in those with persistent or sustained AF (> or =1 week, SAF). There were 90 consecutive patients (mean age 63 +/- 12 years, 67 males and 23 females) with previous PAF (n = 66) or SAF (n = 24). They were maintained in sinus rhythm successfully for at least 1 month after conversion and then studied by transthoracic and transesophageal echocardiography. All of the patients were followed regularly by determination of symptoms, 12-lead ECG and intermittent Holter recording to determine recurrence of AF after echocardiographic study. RESULTS: After 9.1 +/- 3.8 (range 3-12) months of follow-up, 23 of the 90 (26%) patients had documented recurrence of AF (67 without recurrence). Univariate analysis of demographic characteristics, medications, ECG and echocardiographic parameters revealed that, compared with the group of patients without recurrent AF, the group of those with it included more members of the SAF group (11/27 vs. 13/67, p = 0.039), included more male subjects (22/23 vs. 45/67, p = 0.045), had a larger left atrial volume index (LAVI; 27 +/- 9 vs. 22 +/- 9 ml/m2, p = 0.024) and had lower LA appendage peak emptying velocity (LAAPEV; 42 +/- 15 vs. 55 +/- 22 cm/s, p = 0.01). Multivariate Cox proportional hazards regression analysis adjusted for age, gender and AF group revealed that patients with LAVI <30 ml/m2 and LAAPEV >46 cm/s had the least recurrence of AF (relative risk 0.18, 95% confidence interval 0.06-0.55, vs. with LAVI >30 ml/m2 or LAAPEV <46 cm/s, p = 0.002). Kaplan-Meier probability of freedom from AF recurrence was significantly better when LAVI <30 ml/m2 (log-rank p = 0.02), LAAPEV > 46 cm/s (p = 0.013) or both (p = 0.004). The superiority to predict the rate of sinus rhythm maintenance was the same in the PAF and SAF groups. CONCLUSIONS: Good responders to rhythm control in the PAF and SAF groups share the characteristics of smaller LA volume and better LAA contractile function, emphasizing the critical role of atrial substrate remodeling in recurrence of AF.     

Echocardiographic left atrial enlargement. Comparison of vectorcardiogram and electrocardiogram for detection

Standard electrocardiograms (ECG) and Frank vectorcardiograms (VCG) were obtained in 43 consecutive patients in sinus rhythm who had echocardiographic evidence of left atrial enlargement (left atrial internal dimension greater than 4.0 cm; x +/- 1SD = 4.7 +/- 0.5 cm). High gain VCG P loop measurements for the study group were: maximal posterior magnitude, 0.11 +/- 0.03 mv; duration, 106 +/- 14 msec and ratio of maximal posterior to maximal anterior P vector magnitudes, 3.2 +/- 1.4. Thirty of 43 (70%) patients with echocardiographic determined left atrial enlargement had VCGs diagnostic of that condition. Utilizing New York Heart Association criteria for left atrial enlargement, 17 of 43 patients (40%) had ECGs which were diagnostic. Fifteen of 43 (35%) subjects manifested both ECG and VCG criteria for left atrial enlargement and only two patients had diagnostic ECGs and normal VCGs. It is concluded that analysis of high gain VCG P loops provides a 30% higher yield for the diagnosis of echocardiographically determined left atrial enlargement when compared with P wave examination on the standard ECG.     

Reassessment of electrovectorcardiographic signs of left atrial enlargement

Echocardiographic left atrial size was correlated with 27 electrovectorcardiographic parameters in 93 subjects. In 20 of them hemodynamic studies, including calculation of the left atrial volume, were performed. Subjects were divided into four groups as follows: Group I, 21 healthy subjects; group II, 45 patients with heart disease but no left atrial enlargement; group III, 15 patients with heart disease and left atrial size from 4.1 to 5 cm; and group IV, 12 patients with heart disease and a left atrial size exceeding 5 cm. A good correlation was found between left atrial size and the following parameters: Duration of P wave in standard lead II, voltage of both terminal forces of P wave in lead V1 and its maximal vector in the frontal and sagittal planes. A new index (duration/voltage of P wave in lead II) was postulated, which showed an excellent correlation with left atrial size (p less than 0.001). In all cases the superposition between groups was excessive. These findings indicate the limitations of the classical patterns and raise interest in new parameters concerning the electrocardiographic diagnosis of left atrial enlargement.     

Left atrial size—A risk factor for left atrial thrombi in mitral stenosis

In a follow-up study, 77 patients with predominant mitral stenosis were examined to investigate the role of left atrial (LA) enlargement in LA thrombi. Fifteen (19.4%) patients had LA thrombi. Of these, 2 (13.3%) were in sinus rhythm and 13 (86.7%) in atrial fibrillation. Fourteen (93.3%) of the patients with LA thrombi had an LA size≥4.8 cm. Only one (6.7%) patient had an LA size of 4.4 cm and was in atrial fibrillation. The median LA size in patients with LA thrombi was 5.2 cm compared with 4.75 cm in patients without LA thrombi (p<0.01). The relative risk for LA thrombi in patients with an LA size≥4.8 cm compared with patients with an LA size<4.8 cm was 10.0 (95% confidence interval 1.4 to 71.4). It was thus confirmed that LA enlargement≥4.8 cm is an in dependent risk factor for LA thrombi in patients with mitral stenosis.