Influence of regression of left ventricular hypertrophy on left atrial size and function in patients with moderate hypertension

OBJECTIVES: The aim of the study was to evaluate the effect of regression of left ventricular (LV) hypertrophy on left atrial (LA) size and function in patients treated with telmisartan, an angiotensin II receptor blocker. METHODS: Patients population included 80 patients with mild-moderate LV hypertrophy treated with telmisartan. Patients were followed over a period of 12 months from the start of telmisartan treatment. LA size was measured during systole from the parasternal long-axis view from M-mode. Atrial function was assessed by Doppler-echocardiography and the following parameters were measured: transmitral peak A velocity, atrial filling fraction, atrial ejection force (AEF), peak E velocity, deceleration time and isovolumic relaxation time, LA maximal and minimal volume, and LV cardiac mass index (LVMI). RESULTS: All patients had an increased LVMI and decrease during follow-up. LA dimensions were greater at baseline and reduced after 1 year of treatment. LA volume indexes maximal volume, minimal volume and P volume were reduced compared with baseline value (maximal volume from 35+/-5 to 32+/-5, p<0.05; minimal volumes from 14+/-2 to 10+/-4, p<0.05). AEF, a parameter of atrial systolic function, increased from 12+/-3 to 15+/-2.4 (p<0.01). The reduction of LA volumes correlate with reduction of LVMI (LA maximal volume and LVMI r = 0.45; p<0.01; LA minimal volume and LVMI r = 0.34; p<0.05). A positive correlation was also found between LV mass index and P volume (r = 0.41; p<0.01), LV mass index and LA active emptying volume (r = 0.39; p<0.01), and LV mass index and LA total emptying volume (r = 0.38; p<0.05). CONCLUSIONS: The present study suggests that regression of LV hypertrophy due to telmisartan is associated with reduction of LA volumes that expresses variation of LV end-diastolic pressure. The reduction of LV end-diastolic pressure is associated with an increase in diastolic filling and with a significant reduction of active and passive emptying contribution of left atrium to LV stroke volume.     

高血压心脏病左心房收缩功能的超声心动图评价

目的应用超声心动图技术分析高血压病人的左心房收缩功能。方法60例高血压患者、20例健康对照者。根据左室质量指数将高血压病人分为左室构型正常组及左室肥厚组，取组织多普勒的速度模式，将取样容积放在二尖瓣瓣环处，测量心房收缩期的组织运动速度(A’)、衡量其与传统的评价左心房功能的参数如左房射血力、左房动能等的相关性。结果伴随高血压病情的加重，A’、心房收缩期血流峰值速度(A)、LAEF、LASV、左房射血力、左房动能明显增加，高血压组、左室肥厚组、左室构型正常组与健康对照组差异有显著性意义(P＜O．01)；A’与LAEF(r=O．81，P＜O．01)，LASV(r=O．73，P＜O．01，左房射血力(r=O．84，P＜O．01)，左房动能(r=O．81，P＜O．01)呈高度正相关。结论QTVI技术测定的A’是评价高血压病左心房收缩功能有意义的指标。     

Comparison of left atrial volume and function after linear ablation and after cardioversion for chronic atrial fibrillation

Several techniques for treatment of atrial fibrillation (AF) have been developed, including the direct placement of radiofrequency for lesions at open heart surgery. Detailed evaluation of left atrial (LA) function has not been performed after these procedures and has not been compared in patients with chronic AF. We compared the atrial function of patients with sustained sinus rhythm (SR) after linear ablation with a group who underwent direct-current cardioversion and a group of normal controls to investigate the measurable deleterious effects, if any, on atrial function after the surgical procedure. Twenty-one consecutive patients who had maintained SR for >6 months after a linear radiofrequency ablation (LRFA) procedure were studied. As control subjects, we examined 33 patients with chronic AF successfully restored to SR by cardioversion who maintained SR for >6 months and 42 age-matched normal subjects. LA function was decreased in both the LRFA and cardioverted AF groups compared with normal controls. The parameters of LA function, atrial fraction, LA ejection fraction, and the A' velocity were lowest in the LRFA group, intermediate in the cardioverted AF group, and highest in the normal controls (LA function: 15.8 +/- 10%, 26 +/- 10%, 33 +/- 7%; p = 0.0001; LA ejection fraction: 31 +13%, 41 +/- 12%, 51 +/- 9%; p = 0.0001; A' velocity: 4.2 +/- 1.4, 7.6 +/- 2.2, 9.5 +/- 1.9 cm/s; p = 0.0001). LA volumes were increased in the LRFA and cardioverted AF groups compared with normals (62.8 +/- 22 vs 70.6 +/- 17 vs 38.7 +/- 9.8 ml; p = 0.0001). Thus, although LA function is restored and maintained after LRFA has been performed during open heart surgery, LRFA use is associated with a measurable decrease in LA function over and above that found after conventional cardioversion.     

Natriuretic peptide levels in atrial fibrillation: a prospective hormonal and Doppler-echocardiographic study

OBJECTIVES: The objective was to determine the independent association between atrial fibrillation (A-Fib) and activation of natriuretic peptides. BACKGROUND: The association of A-Fib with activation of N-terminal atrial and brain natriuretic peptides (N-ANPs and BNPs, respectively) is uncertain but of great importance for the diagnostic utilization of natriuretic peptides. This uncertainty is related to the lack of appropriate controls, with left ventricular (LV) and atrial overload similar to A-Fib. METHODS: We prospectively measured N-terminal atrial and BNPs and endothelin-1 levels in 100 patients and 14 age- and gender-matched control subjects. The 32 patients with A-Fib were compared with 68 patients in sinus rhythm and similar LV and atrial overload (due to mitral regurgitation or LV dysfunction) measured simultaneously with hormonal levels with comprehensive Doppler echocardiography. RESULTS: Patients with A-Fib compared with those in sinus rhythm had similar symptoms, comorbid conditions, cardioactive medications, pulmonary pressure, left atrial volume, and LV ejection fraction and filling characteristics but demonstrated higher N-ANP levels (2,613 +/- 1,681 vs. 1,654 +/- 1,323 pg/ml, p = 0.007) even after adjustment for the underlying cardiac disease (p < 0.0001). Conversely, BNP levels were similar in both groups (165 +/- 163 vs. 160 +/- 269 pg/ml, p = 0.9). In multivariate analysis, a higher N-ANP level was associated with A-Fib (p = 0.0003), symptom class (p < 0.0001) and endothelin-1 level (p = 0.032) independently of left atrial volume and LV ejection fraction. Conversely, BNP showed no independent association with and was most strongly associated with LV ejection fraction (p < 0.0001). CONCLUSIONS: Atrial fibrillation is an independent determinant of higher N-ANP levels and blurs its association with LV dysfunction. Conversely, the BNP is not independently associated with A-Fib and is strongly determined by LV dysfunction, for which it is an independent marker.     

心房颤动患者复律前后左心房功能变化的超声研究

目的　探讨心房颤动 ( AF )复律后左心房功能变化的特点。方法　选择 AF病人 96例 ,按心脏节律转复的方式分为自发性复律 ( A)组 2 4例 ,药物复律 ( B)组 40例及直流电复律 ( C)组 3 2例 ;分别应用超声心动图测定其左心房内径和容积 ,计算左心房主动和被动排空容积 ,并评价左心房功能。结果　AF时所有病人的左心房扩大 ,而恢复窦性心律后 A、B及 C组左心房内径降低者分别为 10 0 %、74%及 5 2 %。 62例左心房机械功能正常患者与 3 4例左心房功能降低患者比较有更强的左心房射血力 ( LAEF ) ,这与复律后左心房内径降低有关。左心房功能异常( L AEF<7达因 )患者左心房内径和容积分别与左心房射血力呈负相关 ( r=-0 .72和 -0 .76,P<0 .0 0 1)。左心房主动排空分数降低而管道容积却增加。结论　心房颤动复律后 ,左心房机械功能的延迟恢复与持续存在的的左心房扩大有关     

Serial evaluation of left atrial dimension after cardioversion for atrial fibrillation and relation to atrial function

The size of the left atrium is usually increased during atrial fibrillation (AF). The aim of the present study was to evaluate changes in left atrial (LA) dimension after cardioversion for AF, and the relation between LA dimension and atrial function. The initial study population included 171 consecutive patients. Patients who had spontaneous cardioversion to sinus rhythm (56 patients) were compared with patients who had random cardio-version with drugs (50 patients) or direct-current (DC) shock (50 patients). Echocardiographic evaluations included LA size and volume. LA passive and active emptying volumes were calculated, and LA function was assessed. Atrial stunning was observed in 18 patients reverted with DC shock and in 7 patients reverted with drugs. The left atrium was dilated in all patients during AF (48 +/- 5 mm). The size of the left atrium decreased after restoration of sinus rhythm in all patients with spontaneous reversion to sinus rhythm, in 73% of patients reverted with drugs, and in 50% of patients reverted with DC shock. The comparison between patients with a normal mechanical atrial function and patients with reduced atrial function showed that a higher atrial ejection force was associated with a more marked reduction in LA size after restoration of sinus rhythm. A relation between LA volumes and atrial ejection force was observed in the group of patients with depressed atrial mechanical function (r = -0.78; p <0.001). The active emptying fraction was lower, although not significantly, in this group, whereas the conduit volume was increased. Thus, a depressed atrial mechanical function after cardioversion for AF was associated with a persistence of LA dilation.     

心房颤动复律前后左房结构和功能变化的超声心动图研究

目的应用超声心动图观察心房颤动(简称房颤)患者复律前后左房结构和功能的变化。方法选择房颤患者20例,按心脏复律的方式分为直流电复律组7例,药物复律组13例,分别于复律前、复律后第1天、第3天、第7天、第1个月时应用超声心动图测定左房内径和容积,记录二尖瓣血流频谱A峰流速(VA)、A峰速度时间积分(A-VTI)、心房充盈分数(AFF)和左房射血力(LAEF)。分析左房内径、容积变化与左房收缩功能的关系。应用心房肌超声组织定征技术在左房后壁心肌和心包处测量背向散射积分值(IBS)及背向散射积分周期变异幅度(CVIB)评价心肌组织的声学特征。结果房颤时所有患者均存在左房扩大,而恢复窦性心律后直流电复律组和药物复律组的左房上下径均显著降低(P<0.05或0.01)。恢复窦性心律后第1天、第3天直流电复律与药物复律组比较,左房最大和最小容积显著增大(P<0.05或0.01),VA、A-VTI、AFF和LAEF明显降低。房颤时左房心肌标化IBS较健康对照组增大,而CVIB则降低(P均<0.01),直流电复律组恢复窦性心律后第1天、第3天左房心肌标化IBS及CVIB与房颤时比较无差异(P>0.05),而药物复律组左房IBS%与房颤时和直流电复律组比较显著降低,CVIB则显著增大。恢复窦性心律后第7天、第1个月时,两组左房IBS%与房颤时比较均显著降低,CVIB显著增大(P均<0.01),两组无差异。结论两种复律方式成功复律后随时间推移均可改善房颤患者的左房结构重构和功能。     

The left atrial function index: a rhythm independent marker of atrial function.

AIMS: This study evaluates a simple echocardiographic rhythm independent expression of left atrial (LA) function, 'the left atrial function index' (LAFI). BACKGROUND: Quantitation of LA function is challenging and often established parameters including peak A are limited to sinus rhythm (SR). We hypothesized that atrial function could be characterized independent of rhythm by combining analogues of LA volume, reservoir function and LV stroke volume. METHODS: Seventy-two patients with chronic atrial fibrillation (CAF) were followed for six months post cardioversion (CV). Thirty-seven age matched healthy subjects were controls. The LAFI = LAEF x LVOT-VTI/LAESVI (LAEF = LA emptying fraction, LAESVI = maximal LA volume indexed to BSA, LVOT-VTI = outflow tract velocity time integral). RESULTS: The LAFI pre-CV in the CAF group was depressed vs controls (0.10 +/- 0.05 vs 0.54 +/- 0.17; P = 0.0001). Post-CV, LAFI was lower in persistent AF than in those restored to SR (AF vs SR: 0.08 +/- 0.03 vs 0.15 +/- 0.08; P = 0.0001), improved progressively in SR and was unchanged when AF persisted. CONCLUSION: The LAFI, a simple, rhythm independent expression of atrial function, appears sensitive to differences between individuals in AF and those restored to SR and justifies clinical and investigative applications.     

左房机械功能对持续性心房颤动电复律术后疗效的影响

目的探讨左房机械功能对持续性心房颤动(简称房颤)电复律术后疗效影响。方法选择30例持续性房颤成功电复律患者,应用超声心动图测定其电复律术后48 h静息时窦性心律(简称窦律)下最大二尖瓣口面积、A波速度峰值(PMA),E波速度峰值(PME),计算左房射血力,测量左房内径,随访2个月,分析左房机械功能指标与持续性房颤电复律术后复发的关系。结果有11例(36.7%)患者电复律术后2个月复发,复发组左房射血力较窦律维持组明显下降[(8.5±2.4)×10-5N vs(11.4±3.6)×10-5N,P=0.020〗;复发组6例左房机械功能低下,较窦律维持组(5例)显著升高(54.5%vs 26.3%,χ2=4.9,P=0.042)。而复发组左房内径有增大的趋势(37.3±4.1mm vs 34.4±4.2 mm,P=0.077)。结论左房机械功能低下是持续性房颤电复律术后近期复发的危险因素。     

Effects of left ventricular systolic dysfunction on left atrial appendage and left atrial functions in patients with chronic nonvalvular atrial fibrillation

OBJECTIVE: It has been claimed that left ventricular (LV) systolic dysfunction impairs left atrial (LA) and left atrial appendage (LAA) functions. In this study, we compared the LA and LAA function parameters in patients with chronic nonvalvular atrial fibrillation (AF) with and without LV systolic dysfunction. METHODS AND RESULTS: The study population consisted of 28 patients with chronic nonvalvularAF. Group I consisted of 12 patients with LV systolic dysfunction (mean age: 61 +/- 14 years; LV ejection fraction: 44 +/- 6%), group II of 16 patients with normal LV systolic function (mean age: 52 +/- 15 years; LV ejection fraction: 65 +/- 3%). LV ejection fraction (EF) was measured by echocardiography utilizing bi-plane area length method.The following LA and LAA transoesophageal echocardiography parameters were obtained: I) LA diameter, 2) LAA ejection velocity, 3) LAA filling velocity, 4) LAA ejection fraction, 5) pulmonary venous (PV) systolic velocity, 6) PV diastolic velocity, 7) PV systolic velocity/diastolic velocity ratio.The left atrium diameter was significantly larger in group I than in group 11 (4.7 +/- 0.7 cm vs. 3.8 +/- 0.6 cm, p < 0.05).The LAA ejection velocity and LAA ejection fraction were significantly lower in group I than in group 11 (22.6 +/- 15.5 cm/s vs 37.5 +/- 11.3 cm/s and 26.9 +/- 20.8% vs. 41.3 +/- 10.9%, p < 0.05 for both comparisons).The PV systolic velocity and PV systolic velocity/diastolic velocity ratio were significantly smaller in group I than in group II (26.2 +/- 14.8 cm/s vs. 51.5 +/- 22 cm/s and 0.7 +/- 0.6 vs. 1.2 +/- 0.5, p < 0.05 for both comparisons).Although decreased LAA filling and PV diastolic velocities were determined in group I, no significant difference existed between groups I and II.Thrombus and/or spontaneous echo contrast (SEC) in the LA and/or LAA were more frequent in group I (75% vs. 18%, p < 0.05). CONCLUSION: These results indicate that LV systolic dysfunction impairs various LA and LA function parameters and is associated with an increased frequency of SEC and/or LA thrombus in patients with chronic nonvalvularAF.     

Value of left atrial function in predicting exercise capacity in heart failure with moderate to severe left ventricular systolic dysfunction

Left atrial (LA) function is associated with left ventricular (LV) diastolic filling and cardiac output response to exercise. But the relation between LA function and exercise performance has not been adequately evaluated. The aim of this study was to investigate the relation between LA function and exercise capacity in dilated cardiomyopathy (DCM) with cardiopulmonary exercise testing. Forty-four patients with a left ventricular end-diastolic dimension (LVDd) > or = 60 mm and an ejection fraction (EF) < or = 40%, and in normal sinus rhythm were included in this study. Patients were divided into group 1 and group 2 according to their exercise peak oxygen uptake (VO2) (group 1: peak VO2 >14 mL/kg/min, group 2: peak VO2 < or = 14 mL/ kg/min). LA function indices were defined as follows: LA end-systolic diameter (LASd), end-diastolic diameter (LADd), LA systolic volume (LASV), LA diastolic volume (LADV), LA ejection volume (LAEV), and LA ejection fraction (LAEF). LASd, LADd, LASV, and LADV were significantly increased in group 2 (P < 0.001, P < 0.001, P < 0.05, P < 0.005). Group 1 had significantly higher LAEF (P < 0.001 ) and LVEF (P < 0.05). Group 2 had significantly shorter exercise duration, and decreased anaerobic threshold levels and minute ventilation volumes (P < 0.001, P < 0.001, P < 0.005 ). There was a positive correlation between peak VO2 and LVEF (r = 0.46, P = 0.002), and LAEF (r = 0.61, P < 0.001), peak A wave velocity (r = 0.39, P = 0.009), E wave deceleration time (r = 0.56, P < 0.001), and isovolumic relaxation time (IVRT) (r = 0.35, P = 0.04). There was a negative correlation between peak VO2 and LASd (r = -0.53, P < 0.001) LADd (r = -0.59, P < 0.001), LASVI (r = -0.34, P = 0.027), LADVI (r = -0.37, P = 0.001), and the E/A ratio (r = -0.41, P = 0.006), Decreased LAEF and increased LA sizes were associated with decreased peak VO2. The results clearly demonstrate that LA functions at rest are related to exercise performance in patients with heart failure.     

Stunning of the Left Atrium after Conversion of Atrial Fibrillation: Predictor for Maintenance of Sinus Rhythm?

Recurrence of atrial fibrillation (AF) after cardioversion (CV) to sinus rhythm (SR) is determined by various clinical and echocardiographic parameters. The aim of this study was to determine the value of mitral inflow A-wave velocity, performed at 24 hours after CV in estimation of AF recurrence. The study group consisted of 187 consecutive patients with nonvalvular atrial fibrillation, who had been cardioverted to SR from 1998 to 2000. Transthoracic echocardiography was performed in all cases recruited for the study 24 hours after CV. Left atrial (LA) diameter, left ventricular ejection fraction, and mitral inflow A-wave velocity were measured. The patients were evaluated in five groups according to their recurrence time (<30 days, 31-90 days, 91-180 days, 181-365 days, and >365 days). Maintenance of SR was determined to have a negative linear correlation with age (r =-0.97, P = 0.006), LA diameter (r =-0.93, P = 0.02), and AF duration (r =-0.93, P = 0.02), while having a positive linear correlation with mitral inflow A-wave velocity (r = 0.96, P = 0.008). In the maintenance of sinus rhythm, age, LA diameter, and AF duration were not affected from the method of CV, while mitral inflow A-wave velocity was found to be affected with the method of CV. No relationship was determined between mitral inflow A-wave velocity and the maintenance of sinus rhythm in those performed electrical cardioversion, while frequency of recurrence was found to be higher in those with slow mitral inflow A-wave velocity who were performed pharmacological cardioversion (r = 0.89, P = 0.004). In conclusion, age, duration of AF, LA diameter, and the mitral inflow A-wave velocity can be used to predict the maintenance of SR after CV.     

Changes in left ventricular filling and left atrial function six months after nonsurgical septal reduction therapy for hypertrophic obstructive cardiomyopathy.

OBJECTIVES: The purpose of this study was to evaluate changes in left ventricular (LV) filling, left atrial (LA) volumes and function six months after nonsurgical septal reduction therapy (NSRT) for hypertrophic obstructive cardiomyopathy (HOCM). BACKGROUND: Patients with HOCM frequently have enlarged left atria, which predisposes them to atrial fibrillation. Nonsurgical septal reduction therapy results in significant reduction in left ventricular outflow tract (LVOT) obstruction and symptomatic improvement. However, its effect on LV passive filling volume, LA volumes and function is not yet known. METHODS: Thirty patients with HOCM underwent treadmill exercise testing as well as 2-dimensional and Doppler echocardiography before and six months after NSRT. Data included clinical status, exercise duration, LVOT gradient, mitral regurgitant (MR) volume, LV pre-A pressure and LA volumes. Left atrial ejection force and kinetic energy (KE) were computed noninvasively and were compared with 12 age-matched, normal subjects. RESULTS: New York Heart Association (NYHA) class was lower and exercise duration was longer (p < 0.05) six months after NSRT. The LVOT gradient, MR volume and LV pre-A pressure were all significantly reduced. HOCM patients had larger atria, which had a higher ejection force and KE, compared with normal subjects (p < 0.01). After NSRT, LV passive filling volume increased (p < 0.01), whereas LA volumes, ejection force and KE decreased (p < 0.01). Reduction in LA maximal volume was positively related to changes in LV pre-A pressure (r = 0.8, p < 0.05) and MR volume (0.4, p < 0.05). Changes in LA ejection force were positively related to changes in LA pre-A volume (r = 0.7, p < 0.01) and KE (r = 0.81, p < 0.01). The increase in exercise duration paralleled the increase in LV passive filling volume (r = 0.85, p < 0.05). CONCLUSIONS: Nonsurgical septal reduction therapy results in an increase in LV passive filling volume and a reduction in LA size, ejection force and KE.     

Left atrial volume in patients with asymptomatic aortic valve stenosis (the Simvastatin and Ezetimibe in Aortic Stenosis study)

Left atrial (LA) size is known to increase with persistently increased left ventricular (LV) filling pressure. We therefore hypothesized that LA volume might reflect the severity of aortic valve stenosis (AS). Transthoracic echocardiography was performed in 1,758 patients with asymptomatic AS (transaortic Doppler velocity > or =2.5 and < or =4 m/s) in the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study. LA volume was measured in end-systole in the apical 4-chamber view in 1,503 patients (85%), and aortic valve area (AVA) was estimated by the continuity equation and indexed by body surface area. Mean values for age and AVA were 67 +/- 10 years and 1.27 +/- 0.5 cm2, respectively, and 574 were women (38%). Mean value for LA volume indexed (LAVI) was 36 +/- 13 ml/m2. Enlargement of LA volume (> or =32 ml/m2) was found in 57% of patients. AVA indexed was significantly correlated to LAVI (r = -0.1, p = 0.0002). Multivariate analysis showed that LAVI was significantly related to AVA indexed (beta = -4.1, p = 0.007) in a model that also included mitral regurgitation (beta = 2.8, p <0.0001), history of hypertension (beta = 2.2, p = 0.002), LV end-diastolic volume (beta = 0.05, p <0.0001), presence of LV hypertrophy (beta = 3.4, p <0.0001), and restrictive LV filling pattern (beta = 3.5, p = 0.01). Gender and LV ejection fraction were eliminated from the final model. In conclusion, LA volume is often enlarged in asymptomatic patients with AS. Furthermore, LA volume is related to AVA even when adjusting for other known risk factors for increased LA volume including of measurements of diastolic function.     

Improvement of atrial function and atrial reverse remodeling after cardiac resynchronization therapy for heart failure.

OBJECTIVES: We sought to examine whether cardiac resynchronization therapy (CRT) improves atrial function and induces atrial reverse remodeling. BACKGROUND: Cardiac resynchronization therapy is an established therapy for advanced heart failure with prolonged QRS duration, which improves left ventricle (LV) function and is associated with LV reverse remodeling. METHODS: A total of 107 heart failure patients (66 +/- 11 years) who received CRT and were followed up for 3 months were studied. Atrial function was assessed by M-mode, 2-dimensional echocardiography, transmitral Doppler, tissue Doppler velocity, and strain (epsilon) imaging. Left atrial (LA) emptying fraction based on the change in areas (LAA-EF) and volumes (LAV-EF) were calculated. The LV reverse remodeling was defined by a reduction of LV end-systolic volume >10%. RESULTS: In the responders of LV reverse remodeling (n = 62), LAA-EF and LAV-EF were significantly increased (p < 0.001). Responders also had significant decrease in LA size area and volumetric measurements, both before (p < 0.05) and after atrial systole (p < 0.001). However, these parameters were unchanged in the nonresponders (n = 45, p = NS). In the responders, tissue Doppler velocity analysis showed improvement of contraction velocity in both left (p = 0.005) and right atria (p = 0.018), whereas epsilon in both atria were increased in all the phases of cardiac cycle, namely ventricular end-systole (p < 0.001), early diastole (p < 0.001), and late diastole (p = 0.007). CONCLUSIONS: Cardiac resynchronization therapy improves both left and right atrial pump function. The increase in atrial epsilon throughout the cardiac cycle is likely reflecting the improvement of atrial compliance. These changes lead to LA reverse remodeling with reduction of LA size before and after atrial systole.     

Influence of age on the relationship between left atrial performance and left ventricular systolic and diastolic function in systemic arterial hypertension

BACKGROUND: Changes in left ventricular (LV) systolic and diastolic properties may generate variations in left atrial (LA) size and function in many pathophysiological models of LV overload. Besides these states, increasing age may independently influence and magnify LA changes. OBJECTIVE: To investigate the relation of LA size and function to increasing age in hypertensive patients, and to evaluate whether this relationship is influenced by LV function. METHODS: Three hundred thirty-six patients were evaluated using Doppler echocardiography. Maximal LA volume and ejection force were used as indexes of LA size and performance, respectively. RESULTS: Age was positively associated with LA ejection force (r=0.34, P<0.001) and maximal volume (r=0.25, P<0.001). The effect of age was independent of LV mass and LV concentric geometry, which independently influenced LA parameters. The relationship between age and LA ejection force was maintained in patients with and without LV systolic dysfunction, and in those with normal diastolic function, whereas it was lost in those with LV diastolic dysfunction. The relationship between age and LA size was not influenced by either LV systolic or diastolic function. LA ejection force was associated with LV mass and LV concentric geometry in all groups of patients 56 years or older, while no association was found between these variables in patients younger than 56 years. LV mass was systematically linked to maximal LA volume in all classes of age, together with LV end-diastolic volume in all groups of patients 56 years of age or older, and LV concentric geometry in patients 68 years of age or older. CONCLUSIONS: There is a positive relationship between age and LA size and performance in hypertensive patients, which is independent of LV mass and geometry. The effect of age on LA performance is insignificant when diastolic dysfunction occurs.     

Pre-treatment with Irbesartan attenuates left atrial stunning after electrical cardioversion of atrial fibrillation.

AIMS: Left atrial (LA) stunning, the transient impairment of LA function, is responsible for an increased thrombo-embolic risk after cardioversion of atrial fibrillation (AF). Angiotensin receptor blockers (ARBs) attenuate atrial remodelling in AF and could theoretically influence LA stunning. We studied the effect of Irbesartan on LA stunning. METHODS AND RESULTS: We prospectively assigned 50 patients from the outpatient clinic undergoing electrical cardioversion for AF with duration of >4 weeks, into two matched groups: 25 patients were treated with Irbesartan (228+/-93 mg/day) for at least 2 weeks prior to cardioversion (Irbesartan group); 25 patients did not receive ARBs (control group). The groups did not differ concerning age (64+/-13 vs. 63+/-13 years, respectively), AF duration (20+/-18 vs. 20+/-19 weeks), underlying disease, LA diameter (46+/-7 vs. 47+/-9 mm), left ventricular dimensions, and ejection fraction (47.7+/-11.6 vs. 49.7+/-14.5%). We assessed LA appendage emptying velocities (LAAEV) and LA spontaneous echo contrast (LASEC) by transoesophageal echocardiography before and after cardioversion and at 2 weeks, and the A-wave by transthoracic echocardiography after cardioversion, at 2 and at 4 weeks. LA stunning was significantly attenuated in the Irbesartan group. The reduction of LAAEV immediately after cardioversion was significantly less in the Irbesartan group (LAAEV reduction of 9+/-49% from 28+/-9 cm/s before cardioversion to 25+/-13 cm/s immediately afterwards) than in the control group (reduction of 48+/-20% from 34+/-15 cm/s before cardioversion to 16+/-6 cm/s afterwards) (P = 0.048). New or increased LASEC occurred in eight patients (32%) in the Irbesartan vs. 16 patients (64%) in the control group (P = 0.046). CONCLUSION: Irbesartan significantly attenuates LA stunning after electrical cardioversion of AF. Therefore, ARBs may represent an important pharmacological supplementation in patients being prepared for cardioversion.     

Tissue Doppler echocardiographic evidence of atrial mechanical dysfunction in coronary artery disease

BACKGROUND: Atrial function is an integral part of cardiac function which is often neglected. The presence of coronary artery disease (CAD) may impair atrial function. This study investigated if atrial mechanical dysfunction was present in patients with CAD by tissue Doppler echocardiography (TDI). METHODS: Echocardiography with TDI was performed in 118 patients with CAD, and compared with 100 normal controls with comparable age and heart rate. Regional atrial function was assessed at the left (LA) and right (RA) atrial free wall and inter-atrial septum (IAS). The peak regional atrial contraction velocity of (V(A)) and the timing of mechanical events were compared. RESULTS: The V(A) in the LA (5.0+/-2.6 Vs 7.7+/-2.6 cm/s), IAS (4.8+/-1.7 Vs 5.7+/-1.5 cm/s) and RA (6.8+/-3.1 Vs 9.2+/-2.9 cm/s) were significantly decreased in patients with CAD when compared with controls (all p<0.001). Patients with impaired systolic function (ejection fraction50% (both p<0.001); and were lower in those with restrictive filling pattern (RFP) than non-RFP of diastolic dysfunction (both p<0.05). The V(A) in all the subgroups was lower than controls. In contrast, transmitral atrial velocity was unable to reveal any abnormality except in the subgroup with a RFP. The LA dimension, area and volume were increased in the disease groups, but were largely unchanged in the RA despite abnormal V(A). The physiological inter-atrial delay for the onset and peak atrial contraction between the RA and LA were unaffected by CAD. CONCLUSIONS: The atrial contractile function in both atria was impaired in the presence of CAD, especially in the LA. This was detected even in patients with preserved systolic function or mild diastolic dysfunction such as non-RFP. Direct assessment of atrial velocity by TDI may better reflect atrial mechanical function than transmitral atrial velocity.     

Clinical value of left atrial appendage flow velocity for predicting of cardioversion success in patients with non-valvular atrial fibrillation.

BACKGROUND: Echocardiographic parameters for predicting cardioversion outcome in patients with non-valvular atrial fibrillation are not accurately defined. OBJECTIVE: To evaluate the role of left atrial appendage flow velocity detected by transoesophageal echocardiography for prediction of cardioversion outcome in patients with non-valvular atrial fibrillation enrolled in a prospective. multicentre, international study. METHODS: Four hundred and eight patients (257 males, mean age: 66 +/- 10 years) with non-valvular atrial fibrillation lasting more than 48 h but less than 1 year underwent transthoracic echocardiography and transoesophageal echocardiography before either electrical (n=324) or pharmacological (n=84) cardioversion. RESULTS: Cardioversion was successful in restoring sinus rhythm in 328 (80%) and unsuccessful in 80 patients (20%). Mean left atrial appendage peak emptying flow velocity was significantly higher in patients with successful than in those with unsuccessful cardioversion (32.4 +/- 17.7 vs 23.5 +/- 13.6 cm x s(-1); P<0.0001). At multivariate logistic regression analysis, three parameters proved to be independent predictors of cardioversion success: the atrial fibrillation duration <2 weeks (P=0.011, OR=4.9, CI 95%=1.9-12.7), the mean left atrial appendage flow velocity >31 cm x s(-1) (P=0.0013, OR=2.8, CI 95%=1.5-5.4) and the left atrial diameter <47 mm (P=0.093, OR=2.0, CI 95%=1.2-3.4). These independent predictors of cardioversion success outperformed other univariate predictors such as left ventricular end-diastolic diameter <58 mm, ejection fraction >56% and the absence of left atrial spontaneous echo contrast. CONCLUSION: In patients with non-valvular atrial fibrillation, measurement of the left atrial appendage flow velocity profile by transoesophageal echocardiography before cardioversion provides valuable information for prediction of cardioversion outcome.     

A real-time three-dimensional echocardiographic quantitative analysis of left atrial function in left ventricular diastolic dysfunction

The evaluation of left ventricular diastolic function provides important information about hemodynamics and has prognostic implications for various cardiac diseases. In particular, left atrial (LA) volume is an increasingly significant prognostic biomarker for diastolic dysfunction. The aim of this study was to assess left ventricular diastolic function by measuring changes in LA volume using real-time 3-dimensional echocardiography. The 106 subjects were divided into 4 groups (normal, impaired relaxation, pseudonormal, and restrictive) on the basis of diastolic function, as assessed by transmitral flow patterns. LA volume was measured during a heart cycle using real-time 3-dimensional echocardiography. LA stroke volume (maximum LA volume - minimum LA volume) and the LA ejection fraction (LA stroke volume/maximum LA volume x 100) were calculated using Doppler imaging to assess their correlation with other parameters used to evaluate left ventricular diastolic function, including transmitral flow pattern and early diastolic mitral annular velocity (E'). LA volume indexed to body surface area was dilated in subjects with left ventricular diastolic dysfunction, whereas the LA ejection fraction was lower. The maximum LA volume, minimum LA volume, and LA ejection fraction were significantly different between each group, and each was significantly correlated with the ratio of early diastolic transmitral flow velocity (E) to E' (E/E'). The LA ejection fraction correlated best with E/E' (r = -0.68, p <0.0001). In conclusion, cyclic changes in LA volume could be measured using real-time 3-dimensional echocardiography, and measuring LA function with this method may be a viable alternative for the accurate assessment of left ventricular diastolic function.