Effect of left atrial size and function on P-wave dispersion: a study in patients with paroxysmal atrial fibrillation

BACKGROUND: Paroxysmal atrial fibrillation (PAF), a common arrhythmia, is caused by the fractionated and nonhomogeneous propagation of sinus impulse. HYPOTHESIS: This study was undertaken to examine the effect of left atrial (LA) dimension and function on P-wave dispersion (deltaP) in unselected patients with PAF and health controls. METHOD: In this study, 62 consecutive patients with PAF (32 men, 30 women, mean age 55+/-11 years) and 62 age- and gender-matched healthy controls (33 men, 29 women, mean age 52+/-13 years) were studied to compare the effect of LA size, volume, and function on deltaP (difference between maximum and minimum P-wave duration on 12-lead electrocardiogram). RESULTS: P-wave dispersion in patients with PAF and normal LA diastolic diameter (LAD) was longer than that in controls with normal LA size (53+/-8 vs. 34+/-8 ms, p < 0.001). P-wave dispersion increased in patients with PAF (62+/-12 vs. 53+/-8 ms, p = 0.003) and controls (40+/-7 vs. 34+/-8 ms, p = 0.005) with increased LAD. Presence or absence of PAF did not interact with LAD for their effect on deltaP (2 x 2 analysis of variance test p = 0.20). In the PAF group, deltaP correlated with LAD (r = 0.43, p = 0.002), LA diastolic volume (r = 0.6, p < 0.001), and LA ejection fraction (AEF) (r = - 0.33, p = 0.05). The AEF was preserved when LAD increased in the patients without PAF (0.52+/-0.07 vs. 0.57+/-0.10, p = NS), however was significantly decreased in the PAF group (0.37+/-0.12 vs. 0.49+/-0.10, p = 0.01). On multivariate logistic regression analysis, only deltaP retained significance on development of PAF. CONCLUSION: It was concluded that deltaP increased in patients with PAF and normal LA size. In controls with increased LA size, deltaP increased but did not reach the levels attained in patients with PAF. The AEF was decreased in patients with PAF but was preserved in those without PAF. These findings can be explained by the changes in LA microarchitecture which concurrently decreased atrial myocardial contraction, increased deltaP, and predisposed to PAF.     

Time course of left atrial mechanical recovery after linear lesions: normal sinus rhythm versus a chronic atrial fibrillation dog model

INTRODUCTION: The extent of left atrial (LA) mechanical function recovery after creation of linear lesions using the loop catheter has not been determined. METHODS AND RESULTS: LA mechanical function was assessed before and after linear lesions using transthoracic two-dimensional and Doppler echocardiography in two groups: (1) normal, which consisted of eight healthy dogs in normal sinus rhythm (NSR); and (2) atrial fibrillation (AF), which consisted of nine dogs in spontaneous AF for 6 months following rapid pacing-induced AF. NSR was restored with linear lesions in all AF dogs. All animals were in NSR 5 months after linear lesions. In the normal dogs, the maximal velocity of the transmitral flow "A" wave was reduced by 42% during the first week postablation and by 24% at 5 months versus preablation. At 5 months, no differences in LA function were noted between the normal and the AF group for all measured Doppler parameters. At 5 months, the LA systolic area in AF dogs was reduced by 40% (preablation 12.9 +/- 2.9 cm2, postablation 7.6 +/- 1.2 cm2; P < 0.01) and in the normal dogs by 21% (preablation 10.0 +/- 0.9 cm2, postablation 7.8 +/- 1.2 cm2; P < 0.02), being the same in both groups within 3 months of recovery. CONCLUSION: The creation of linear lesions with the loop catheter does not result in LA expansion. In normal dogs, LA mechanical activity is reduced for 3 weeks postablation. The time course of LA mechanical function recovery is the same for the AF and the NSR dogs, and it is complete at 3 months postablation. At 5 months, LA systolic function parameters in both groups are reduced by 24% versus the preablation values of the normal dogs. Linear lesions result in a significant reduction in LA size.     

Evaluation of left atrial mechanical function and atrial conduction abnormalities in Maras powder (smokeless tobacco) users and smokers

Tobacco use can be classified into smoking and smokeless tobacco. Smokeless tobacco is chewed or is absorbed by the nasal and oral mucosae. A type of smokeless tobacco called Maras powder (MP) is used mostly in the south-eastern region of Turkey, and in many cases users become addicted. It is obtained from a tobacco plant species known as Nicotiana rustica Linn. Nicotine concentrations in the tobacco used to produce MP are eight to 10 times higher than those in tobacco used to produce cigarettes.1 MP and its negative effects on the cardiovascular system have been well studied. MP is consumed in such a way that increase in oxidative stress is inevitable and as a result it accelerates the atherosclerotic process.2,3Cigarette smoke includes nicotine and toxic substances such as carbon monoxide and polycyclic aromatic hydrocarbons.4 Inhalation of these substances predisposes to several different atherosclerotic syndromes,5,6 and is also associated with the occurrence of cardiac arrhythmia.7,8The pathophysiological mechanism of cigarette smoking-induced cardiac arrhythmia is complicated, and the pro-fibrotic effect of nicotine on myocardial tissue with its consequent increased susceptibility to catecholamines, may play a role. Moreover, other components of cigarette smoking, such as carbon monoxide, as well as oxidative stress, are likely to cause the generation of arrhythmias. It is also known that cigarette smoking leads to cardiac autonomic dysfunction,9 and it has been implicated in prolonged QT intervals in healthy individuals.10 However, the nicotine concentration in the blood is more likely to cause the pro-arrhythmic effect of cigarette smoking.7,11 The risk of atrial and ventricular arrhythmia rises due to increased nicotine levels.9-12The prolongation of intra- and inter-atrial electromechanical intervals and the inhomogeneous propagation of sinus impulses are well-known electrophysiological characteristics of atria that are prone to fibrillation.13 Left atrial (LA) volume and LA mechanical function have recently been identified as a potential indicator of cardiac disease and arrhythmias.14,15 Prolongation of atrial electromechanical interval and impaired LA mechanical function are associated with adverse clinical events, including atrial fibrillation, stroke, diastolic dysfunction and left ventricular failure.16,17LA mechanical function and atrial conduction abnormalities have not been investigated in MP users and smokers. Therefore, our study was planned to evaluate whether MP damages intra- and inter-atrial conduction intervals and LA mechanical function as much as cigarette smoking.     

P wave dispersion and left atrial appendage function for predicting recurrence after conversion of atrial fibrillation and relation of p wave dispersion to appendage function

BACKGROUND: We investigated P wave dispersion and left atrial appendage (LAA) function for predicting atrial fibrillation (AF) relapse, and the relationship between P wave dispersion and LAA function. METHODS: Sixty-four consecutive patients with AF lasting /=5 days, LA size >/=45 mm, maximum P wave duration >/=112 ms, P wave dispersion >/=47 ms, spontaneous echo contrast, minimum LAA area >/=166 mm(2), and LAA emptying velocity <36 cm/sec were univariate predictors of recurrence (each P < 0.05). By multivariate analysis, LA size (P = 0.02), P wave dispersion (P < 0.001), and LAA emptying flow (P = 0.01) identified patients with recurrent AF. Their positive predictive values were 91, 97, and 72%, respectively. CONCLUSION: The increased P wave dispersion in addition to the dilated LA and the depressed LAA emptying flow can identify patients at risk of recurrent AF after cardioversion.     

心房颤动患者经导管射频消融术后不同时期左心房结构及功能的动态变化

目的:观察射频消融术对阵发性和持续性心房颤动(房颤)患者左心房结构和功能不同时期的影响。方法:临床诊断房颤的79名患者作为研究对象(阵发性房颤组65例、持续性房颤组14例),随访1年,行超声心动图检查监测左心房最大面积(左心房左右径×上下径)、左心房最大容积(LAVmax)、左心房最小容积(LAVmin)、左心房P容积(LAVp)等左心房结构指标,并通过左心房被动射血分数(LAPEF),左心房主动射血分数(LAAEF),左心房排空容积等指标探讨左心房功能的变化。体检非房颤人群22例作为对照组。全部数据采用SPSS17.0软件包进行统计学分析。结果:①消融术前检测显示:房颤组左心房最大面积、LAVmax、LAVmin均高于正常对照组(P0.05);并且持续性房颤组左心房增大更显著(P0.05)。房颤组LAAEF低于正常对照组(P0.05),其中持续性房颤组下降更明显(P0.05)。LAPEF及左心房排空容积各组间差异无统计学意义。②两组房颤患者术后左心房最大面积、LAVmax较术前均有变小(P0.05),但两者出现变化的时间点不同,阵发性房颤组在术后1年明显变小(P0.05),持续房颤组在术后近期就出现明显变小(P0.05)。两组LAAEF、LAPEF、排空容积等较术前均无显著性变化。③持续性房颤组左心房最大面积术后近期、中期变化率大于阵发性房颤组(P0.05),但至术后1年变化率两者差异无统计学意义。结论:经导管射频消融术能缩小房颤患者增大的左房结构,近、中期在持续性房颤患者更加显著;经导管射频消融术本身对左心房功能无明显影响。     

Influence of age on left atrial appendage function in patients with nonvalvular atrial fibrillation

BACKGROUND: Age is an independent risk factor for thromboembolism in nonvalvular atrial fibrillation (NVAF). An association between low left atrial appendage (LAA) Doppler velocities and thromboembolic risk in NVAF has been reported. Hypothesis: The study was undertaken to identify age-related differences in LAA function that may explain the higher thromboembolic rates in older patients with NVAF. METHODS: Forty-two consecutive patients (age 69+/-2 years [range 42-92], 24 [57%] men) with NVAF underwent transthoracic and transesophageal echocardiography. The following were compared in 22 patients younger and 20 older than 70 years: left ventricular (LV) diameter, mass and ejection fraction, left atrial (LA) diameter and volume, LAA area and volume, LAA peak emptying (PE) and peak filling (PF) velocities, presence and severity of spontaneous echo contrast (SEC) and mitral regurgitation (MR). RESULTS: Left atrial diameter (4.6+/-0.1 vs. 4.5+/-0.2 cm), LA volume (105+/-10 vs. 92+/-8 ml), LAA area (6.8+/-0.6 vs. 5.2+/-0.8 cm2), and LAA volume (5.6+/-0.9 vs. 3.9+/-1.0 ml) were similar (p>0.05) in both groups. Older patients had lower LAA PE (26+/-2 vs. 34+/-3 cm/s, p = 0.02) and PF (32+/-2 vs. 41+/-4 cm/s, p = 0.04) velocities, lower LV mass (175+/-13 vs. 234+/-21 gm, p = 0.02), higher relative wall thickness (0.52+/-0.02 vs. 0.43+/-0.03, p = 0.02), smaller LV diastolic diameter (4.3+/-0.1 vs. 5.2+/-0.2 cm, p < 0.001), and higher LV ejection fraction (62+/-2 vs. 55+/-2%, p = 0.025). Frequency and severity of SEC and MR were similar in both groups. Multivariate analysis identified older age as the only significant predictor of reduced LAA velocities. CONCLUSION: Compared with younger patients, older patients with NVAF have lower LAA velocities despite higher LV ejection fraction, smaller LV size, and similar LA and LAA volumes. These findings may explain the higher thromboembolic rates in older patients with NVAF.     

Effect of age and sex on left atrial morphology and function.

AIMS: Left atrial function is abnormal in a wide range of cardiac diseases. This study was designed to assess the effects of normal ageing and sex on left atrial morphology and function. METHODS AND RESULTS: Echocardiography was performed in 123 subjects (age 57 +/- 19 years, range 22 to 89 years, 59 women) with no evidence of cardiovascular disease. M-mode derived left atrial size, B-mode derived left atrial maximal and minimal volumes, and the volume at onset of atrial systole (P-volume) were measured. Left atrial filling, active and passive emptying volumes and ejections fractions, and expansion index were calculated. Subjects were divided into four groups according to age. Left atrial diameter increased with age, with significantly smaller left atrial size in younger subjects. The oldest subjects had significantly higher (P<0.05) left atrial minimal, maximal and P-volume indices. Filling volume index was highest in the oldest subjects (21.9 +/- 5.6 ml/m(2)). Passive emptying volume index was the lowest in those of middle age (10.5 +/- 2.8 ml/m(2)). Active emptying volume index progressively increased with age (P<0.001). Left atrial expansion index and active emptying fraction were not different between the age groups. There was significant difference in passive emptying fraction (P<0.001) with highest values in the youngest (44.7 +/- 7.3%) and lowest values in the oldest subjects (33.6+/-5.4%). CONCLUSIONS: Age- and sex-related reference values of echocardiographic indices of left atrial morphology and function are reported. Ageing is associated with left atrial dilatation. Left atrial conduit function deteriorates with age while reservoir and pump function are maintained. Left atrial anteroposterior diameter is smaller in women than in men, but overall left atrial function is not influenced by sex.     

Left ventricular systolic and diastolic function after anthracycline chemotherapy in childhood

BACKGROUND: In childhood, late cardiotoxicity is characterized by inappropriately thin wall and consequent increased end-systolic wall stress, but the associations of impaired left ventricular geometry and function occurring under these circumstances need further investigation. HYPOTHESIS: The purpose of this study was to assess anthracycline late effects on the relationships occurring between increased end-systolic stress (ESS) and changes in both M-mode systolic measurements (i.e., endocardial and midwall fractional shortening) and Doppler diastolic indices in the pediatric age. METHODS: The population consisted of 101 children treated with anthracyclines for at least 12 months and 91 healthy children. Using M-mode echocardiography, end-systolic wall stress was calculated as index of afterload, and endocardial and midwall fractional shortening as systolic indices. Doppler transmitral measurements were made as diastolic indices. RESULTS: Patients treated with anthracyclines showed significantly lower relative wall thickness and left ventricular mass index, greater end-systolic wall stress, reduced endocardial and midwall fractional shortening and peak E/A ratio, prolonged deceleration, and isovolumic relaxation times. Direct relationships were found between end-systolic wall stress and both endocardial and midwall shortening. The use of midwall shortening in the relation showed a greater, but not significant increase (from 3 to 6%) in the proportion of patients with depressed systolic function than did endocardial shortening. In the anthracycline group, end-systolic wall stress was also inversely related to relative wall thickness and directly to isovolumic relaxation time. CONCLUSIONS: In childhood, reduced myocardial thickness and increased afterload explain much of systolic and diastolic dysfunction of late anthracycline toxicity. Midwall fractional shortening does not seem to add useful information for identifying subsets of children more prone to the development of heart failure.     

经导管环肺静脉左房线性消融术对阵发性心房颤动患者左心房结构和功能的影响

目的: 评价环肺静脉左房线性消融术对阵发性心房颤动（房颤）患者左心房结构和功能的影响。方法: 阵发性房颤患者33例,Carto系统下行环肺静脉左房线性消融术,应用超声心动图测定其消融术前1～3 d、术后1、3、6、12个月静息时窦性心律下左心房内径、容积指标、二尖瓣口A波速度峰值(VA)及E波速度峰值(VE),并计算左心房排空分数,分析消融术前后左心房结构和功能的变化。结果: 33例阵发性房颤患者均成功施行环肺静脉左房线性消融术,1年治愈率82%。左房前后径消融术后1个月较术前显著增大［(44±4)mm vs. （41±3）mm,P<0.01］,术后3个月、6个月时与术前比较无显著差异,随访1年时左房前后径较术前有显著减小［（40±3）mm vs. (41±3)mm,P<0.05］。与左心房辅助泵功能相关的左心房最小容积,术后1个月显著增大,左心房主动排空分数、左心房总排空分数显著降低（P<0.05),术后3个月时恢复到术前水平。VA术后均低于术前（P<0.05,P<0.01）,而VE/VA术后1个月显著上升（P<0.05,P<0.01）,但在随后的随访中与术前无显著差异。 结论: 阵发性房颤患者左房环肺静脉线性消融术后近期左房前后径增大,辅助泵功能下降,术后3个月恢复至术前水平,术后1年左房结构可部分逆重构。     

Assessment of systolic and diastolic left ventricular and left atrial function using vector velocity imaging in Takotsubo cardiomyopathy

Five adult patients with Takotsubo cardiomyopathy (TC) diagnosed by usual criteria were studied with velocity vector imaging (VVI) on admission and at follow-up, when their LV function had improved, as assessed by 2D TTE wall-motion score (WMS) index. Averaged peak segmental longitudinal strain (S) in systole, and velocity (V) and strain rate (SR) in both systole and diastole were measured from apical 4- (A4C) and 2-chamber views (A2C) in all patients. The data obtained by VVI were analyzed separately for involved and uninvolved segments, which were independently assessed by WMS. In the involved segments, systolic S, V, SR, and diastolic SR improved (P-value < 0.05) on follow-up. Diastolic V showed a trend toward improvement but did not reach statistical significance. In the uninvolved segments, none of the parameters improved significantly either during systole or diastole. In three of these five patients, left atrial (LA) walls were also studied by placing region of interest (ROI) points in the middle of each wall. Peak segmental LA systolic and diastolic V and SR as well as systolic S were obtained for both involved and uninvolved LA walls which were assessed independently using WMS similar to LV. In the involved LA walls, none of the atrial systolic and diastolic parameters changed significantly but all parameters with the exception of systolic V showed a tendency toward improvement during follow-up. Among the uninvolved LA walls, none changed significantly but atrial systolic SR and, diastolic V and SR tended to increase during follow-up. Our retrospective study using VVI demonstrates that TC patients also have LV systolic and diastolic longitudinal dysfunction, not just systolic radial dysfunction as assessed by traditional 2D TTE indices. Longitudinal LA dysfunction may also be present.     

二维斑点追踪技术在同年龄段尿毒症患者左房功能中的研究

目的 应用超声心动图评价尿毒症患者左房大小及功能,并探讨年龄对其影响.方法 选取金山医院肾内科2016年1月-2018年6月期间常规透析治疗尿毒症患者174例及性别、年龄相匹配的正常人55例为研究对象,按年龄＜45岁、45～64岁及≥65岁分成青年组、中年组和老年组.超声心动图测量左房内径、容积及左房射血分数(LAEF...     

Left atrial conduit function for left ventricular filling dynamics in patients with myocardial infarction

This study observed the left atrial function in determining filling dynamics of the left ventricle in patients with myocardial infarction. The study consisted of eight control subjects and ten patients with myocardial infarction. The left ventricular filling volume is considered to be composed of the left atrial passive emptying, active emptying, and conduit volumes. The change of left ventricular filling volume was correlated with that of conduit volume (r = .87, P < .01). However, the change of left ventricular filling volume did not have any correlation to those of left atrial passive emptying and active emptying volumes. These results suggested that the left atrial conduit function was important in determining filling dynamics of the left ventricle.     

Monitoring left ventricular function in adults receiving anthracycline-containing chemotherapy

AIMS: To assess prospectively (1) the incidence of early anthracycline-induced cardiotoxicity; (2) the best predictor for identifying individuals at risk of developing functional cardiotoxicity; and (3) the most sensitive standard echocardiographic measure for the detection of anthracycline-induced changes in left ventricular (LV) function. METHODS: Sixty-seven consecutive patients (45 male, mean age 50+/-18 years) requiring doxorubicin-containing chemotherapy were enrolled. Clinical and echocardiographic assessments occurred before they received any anthracycline, after low-dose anthracyclines and 1-3 months after completion of their chemotherapy. RESULTS: Twenty six percent of patients without significant pre-existing cardiac disease developed cardiotoxicity. The parameter that best predicted the development of functional cardiotoxicity was the change in EF between baseline and low dose with an area under the curve of 0.92. The Tei index detected declines in LV function earlier in the course of treatment with anthracyclines and to a greater significance than any other standard echocardiographic measurement but did not predict functional cardiotoxicity. CONCLUSIONS: All patients receiving potential cardiotoxic chemotherapy should be under the care of a cardiologist and have their EF monitored closely.     

Assessment of left atrial appendage function by transesophageal echocardiography in patients two weeks after acute coronary syndromes

Background For many years in ischemic heart disease, ventricles rather than atria received attention so not much is known about left atrial function in left ventricular ischemia. Objective Our study aimed to evaluate left atrial appendage (LAA) function by means of biplane transesophageal echocardiography in patients ten days after acute coronary syndromes (ACS). Methods The study was performed on 16 adult patients (65.9±9.9 years old) in whom transesophageal echocardiography was done 10 days after ACS. The following left atrial appendage (LAA) planimetric parameters were analyzed: LAA transversal dimension, LAA longitudinal dimension,LAA maximal area, and LAA minimal area. LAA ejection fraction was calculated and analyzed. The following LAA Doppler parameters were analyzed: the peak LAA emptying and the peak LAA filling velocities. The control group consisted of 14 patients (43±14.6 years old) without cardiovascular diseases. Results Both LAA longitudinal dimension and LAA transversal dimension were significantly higher in patients with ACS than in control patients. The same was observed for LAA maximal area. Also LAA ejection fraction was higher in patients with ACS . LAA minimal area did not differ in the patients in either group. LAA peak emptying flow (LAAE) and LAA peak filling flow (LAAF) were significantly higher in patients of the study group than of the control group. Conclusion Our study shows that two weeks after acute coronary syndrome LAA as a reservoir as well as a pump works at a higher level than it does in the control group. (J Geriatr Cardiol 2005; 2(4):198-201)     

Strain and strain rate imaging in evaluating left atrial appendage function by transesophageal echocardiography

BACKGROUND: This study was planned to assess whether strain rate (Sr) and strain (S) echocardiography is a useful method for functional assessment of the left atrial appendage (LAA). MATERIAL AND METHODS: Fifty-seven consecutive patients underwent a clinically indicated study. LAA late empty velocity (LAAEV) was calculated as a gold standard for left atrial appendage function. Real-time 2-dimensional color Doppler myocardial imaging data were recorded from the LAA at a high frame rate. Analysis was performed for LAA longitudinal strain rate and strain from midsegment of lateral wall of LAA. LAA strain determines regional lengthening expressed as a positive value or shortening expressed as a negative value. Peak systolic values were calculated from the extracted curve. RESULTS: Spearman correlation test results showed a statistically significant positive correlation was between the S, Sr variables and LAAEV (LAAEV vs S; r = 0.886, P < 0.001; LAAEV vs Sr: r = 0.897, P < 0.001, respectively). Strain and strain rate values were also significantly lower in patients with spontaneous echocardiographic contrast when compared with those without (strain; 2.42 +/- 0.98 vs 13.1 +/- 5.9, P < 0.001 and strain rate: 0.97 +/- 0.54 vs 3.34 +/- 1.15, P < 0.001, respectively). In addition, LAA strain and strain rate values were significantly lower in the patients with LAA thrombus (strain; 2.15 +/- 0.96 vs 8.35 +/- 6.9, P < 0.001, strain rate; 0.79 +/- 0.46 vs 2.30 +/- 1.48, P < 0.001, respectively). CONCLUSION: S and Sr imaging can be considered a robust technique for the assessment of the LAA systolic deformation.     

斑点追踪技术评价乳腺癌化疗前后左心室局部收缩功能

目的探讨斑点追踪技术（STI）对乳腺癌化疗前后左心室局部收缩功能的评价。方法应用STI检测乳腺癌术后化疗患者左室短轴切面,乳头肌水平的前间壁、后壁的应变曲线,分析并计算左心室局部收缩功能,并与健康对照组进行比较分析。结果①对照组乳头肌水平切面前间壁平均心肌运动速率（MV）、环向应变率（CSR）、径向应变率（RSR）、角速度（AV）、角位移（AE）分别为（2．745±0．330）cm／s、（1．265±0．330）s-1、（1．462±0．460）s-1、（51．224±0．420）°／s和（2．598±0．330）°,化疗组分别为（1．282±0．300）cm／s、（0．271±0．290）S-I、（0．319±0．280）s-1、（25．812±0．290）o／s和（O．339±0．270）°;对照组乳头肌水平切面后壁平均MV、CSR、RSR、AV、AE分别为（2．504±O．240）cm／s、（1．149±0．360）s-1、（1．234±0．210）s-1、（25．998±0．310）°／s和（0．976±0．340）-1,化疗组分别为（1．133±0．280）cm／s、（0．359±0．300）s-1、（0．179±0．220）s-1、（10．915±0．210）。／s和（0．212±0．270）。。与对照组比较,化疗组乳头肌水平切面前间壁、后壁的MV、CSR、RSR、AV、AE均减低,差异具有统计学意义（P〈0．05）。②对照组平均左室射血分数（LVEF）、收缩末期左室内径（LVDd）、收缩末期室间隔厚度（IvsTd）、收缩末期左室后壁厚度（LVPwTd）分别为（65．12±1．45）％、（41．53±2．45）mm、（7．71±0．42）mm和（7．61±0．32）mm,化疗组分别为（63．87±1．03）％、（40．56±2．16）mm、（8．44±0．67）mm和（8．29±0．61）mm,两组比较差异无统计学意义（P〉0．05）。结论斑点追踪技术能够早期、准确地评价乳腺癌化疗前后左室局部收缩功能,为临床早期治疗及预后判断提供有价值的信息。     

Relationship between left atrial appendage function and plasma concentration of atrial natriuretic peptide.

BACKGROUND: It has been reported that the most intensely granuled cardiocytes secreting atrial natriuretic peptide (ANP) are located in the atrial appendages. AIMS: To evaluate the mechanisms of ANP release in congestive heart failure. METHODS AND RESULTS: The relationship between ANP and left atrial appendage (LAA) function was evaluated in 36 patients who underwent both transoesophageal echocardiography and cardiac catheterization. ANP level correlated positively with mean pulmonary capillary wedge pressure (mPCWP; r=0.75, P<0.0001), whereas it showed no significant correlation with the mean right atrial pressure. mPCWP correlated positively with the maximal LAA area (LAAa; r=0.79, P<0.0001) and negatively with the LAA ejection fraction during atrial contraction (LAA-EF; r=-0.61, P<0.0001) and peak late diastolic LAA emptying flow velocity (LAAF; r=-0.69, P<0.0001). ANP level correlated negatively with the LAA-EF (r=-0.56, P<0.001) and with LAAF (r=-0.61, P<0.0001). ANP level correlated more closely with the LAAa (r=0.79, P<0.0001) than with maximal LA volume (r=0.34, P<0.05). Multiple stepwise regression analysis selected LAAa as the only factor independently related to the plasma concentration of ANP (ANP=-22.4+28.6 LAAa, r=0.79, P<0.0001). CONCLUSIONS: We conclude that the factor most predictive for ANP in patients with left-sided cardiac dysfunction is distension of the LAA wall rather than elevation in the LA pressure or distension of the body of LA. This is consistent with the known distribution of ANP-secreting cardiocytes.