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.     

Echocardiographic evaluation of the left atrium and left atrial appendage function in patients with atrial septum aneurysm: implications for thromboembolic complications

BACKGROUND: Our study aimed to assess left atrium (LA) and left atrial appendage (LAA) function in patients with atrial septum aneurysm (ASA) and to relate it to thromboembolic complications. METHODS: The study group comprised 25 patients with isolated ASA (group I) and 17 clinically healthy subjects (control group = group II). Transthoracic and transesophageal echocardiography were performed in all investigated patients. RESULTS: In group I, the following parameters were significantly higher than in the controls: LA minimal dimension (LA (min)) was 2.13 vs. 1.7 cm; LA presystolic dimension (LA (a)) was 2.66 vs. 2.29 cm and LA pre-ejection period/LA ejection time index (PEP/ETLA) was 1.26 vs. 0.41 ( P < 0.05). There were no statistically significant differences between groups as to P wave and PR-interval duration, which were 69 vs. 72 ms and 167 vs. 173 ms, respectively. All LAA parameters were investigated, but LAA minimal areas (LAA (area min)) were higher in the study group than in controls: LAA transversal dimension (LAA (trans)) was 1.89 vs. 1.32 cm; LAA longitudinal dimension (LAA (long)) was 4.24 vs. 3.11 cm; LAA maximal area (LAA (area max)) was 4.35 vs. 3.1 cm (2); LAA ejection fraction (EFLAA) was 56 vs. 33 %; LAA peak emptying (LAAE) was 0.64 vs. 0.41 m/s, and filling velocities (LAAF) was 0.55 vs. 0.42 m/s ( P < 0.05). The results indicate a depression of LA systolic and an enhancement of LAA function in patients with ASA compared with clinically healthy subjects. CONCLUSION: (1) Atrial septum aneurysm impairs left atrium systolic function. (2) In patients with atrial septum aneurysm, left atrium appendage function changes; its systolic as well as a reservoir function improve. (3) The enhancement of LAA function in ASA may be a compensatory mechanism for LA systolic function deterioration. (4) As LAA systolic function is enhanced, it is rather unlikely that LAA is the place of origin of thrombi, which occur relatively frequently (according to the literature) in patients with ASA. The thrombi seem to be formed in the bulging sack of ASA, i.e., in the part of the LA whose systolic function is depressed.     

Relationship of left atrial appendage function to left ventricular function

BACKGROUND: The study was conducted to evaluate the relationship of left atrial appendage function to left ventricular function and to analyze, if left ventricular dysfunction predisposed to left atrial appendage thrombus formation even in the presence of sinus rhythm. METHODS AND RESULTS: The study was conducted in 78 patients with a mean age of 53+/-8.5 years, all of whom were in sinus rhythm. Transesophageal echocardiography was performed to record the left atrial appendage emptying and filling velocity and to look for the presence of spontaneous echo contrast and thrombus. Patients with severe left ventricular dysfunction (Group I--left ventricular ejection fraction < 35%) and patients with moderate left ventricular dysfunction (Group II--left ventricular ejection fraction 35-45%) had lower left atrial appendage emptying velocity (33.6+/-16 and 39.7+/-19.5 cm/s, respectively) and filling velocity (41+/-14.7 and 41+/-17 cm/s, respectively) when compared to patients with preserved systolic function (Group II--left ventricular ejection fraction >45%), who had emptying and filling velocity of 55+/-16 and 56+/-15 cm/s, respectively (p <0.05). Twelve out of 32 (38%) patients with severe left ventricular dysfunction (Group I) and 7 out of 25 (28%) patients with moderate left ventricular dysfunction (Group II) had presence of left atrial appendage thrombus as compared to none of the patients with preserved left ventricular ejection fraction (Group III) (p <0.001). CONCLUSIONS: Patients with left ventricular dysfunction also had left atrial appendage dysfunction as evidenced by lower emptying and filling velocities and had increased incidence of thrombus formation.     

Pattern of left ventricular diastolic filling associated with right ventricular enlargement

Right ventricular (RV) dilatation associated with pressure overload may alter left ventricular (LV) geometry resulting in abnormal diastolic function as demonstrated by a smaller LV diastolic volume for a given LV diastolic pressure. To determine whether abnormalities in LV geometry due to RV dilatation result in abnormalities in the LV diastolic filling pattern, we obtained pulsed Doppler transmitral recordings from 23 patients with RV dilatation with RV systolic pressure estimated to be less than 40 mm Hg (group 1), 18 patients with RV dilatation and RV systolic pressures greater than or equal to 40 mm Hg (group 2) and 33 normal patients. RV systolic pressures were estimated from continuous wave Doppler peak tricuspid regurgitation velocities using the modified Bernoulli equation. Diastolic filling parameters in group 1 patients were similar to normals. In group 2 patient, increased peak atrial filling velocity (76 +/- 14 vs 57 +/- 12 cm/s, p less than 0.001), decreased peak rapid filling velocity/peak atrial filling velocity (1.1 +/- 0.4 vs 1.5 +/- 0.4, p less than 0.01), increased atrial filling fraction (41 +/- 14 vs 30 +/- 10%, p less than 0.01) and prolongation of the atrial filling period (171 +/- 47 vs 152 +/- 39 ms, p less than 0.05) were noted compared with the normal group. RV end-diastolic size and LV end-systolic shape were significantly correlated with the atrial filling fraction in group 2 patients. In patients with RV dilatation and RV systolic pressures greater than or equal to 40 mm Hg, there is increased reliance on atrial systolic contribution to the LV filling volume.     

Left atrial dysfunction in patients with atrial fibrillation after successful rhythm control for > 3 months

BACKGROUND: Large-scale clinical trials have demonstrated that patients with atrial fibrillation (AF), when treated with a rhythm-control strategy, are still at risk for embolic events. We hypothesized that left atrial (LA) dysfunction persisted even after successful maintenance of sinus rhythm for > 3 months. METHODS: A total of 93 patients with AF and satisfactory rhythm control for > 3 months were included. Satisfactory rhythm control was defined as being free of AF based on patient-reported symptoms, monthly ECG follow-up, and ambulatory Holter ECG if needed. Among the 93 patients, 25 patients had sustained AF that was terminated by electrical or pharmacologic cardioversion, while 68 patients had paroxysmal AF under good medical control. Clinical data were obtained, and transthoracic and transesophageal echocardiography were performed after satisfactory rhythm control for > 3 months. RESULTS: Among the 93 patients, 34 patients (37%) had LA dysfunction, defined as LA appendage (LAA) peak emptying velocity < 40 cm/s or spontaneous echo contrast and/or thrombus in the LA or LAA. When compared to the other 59 patients without LA dysfunction, they had larger LA dimension (40 +/- 6 mm vs 36 +/- 8 mm [+/- SD], p = 0.018) but did not differ significantly regarding the left ventricular (LV) chamber size, LV ejection fraction, mitral or tricuspid inflow, and ratio of the amplitude of the waves created by early diastolic filling and atrial contraction. We also analyzed the relationship between LA function and clinical risk factors for stroke, including hypertension, diabetes mellitus, coronary artery disease, age > 65 years, and prior cerebral vascular accident. LA dysfunction was found in 10 of 17 patients (59%) with three or more risk factors. The odds ratio for having LA dysfunction was 3.1 (p = 0.04; 95% confidence interval, 1.1 to 9.1) when compared with patients with less than three risk factors. CONCLUSIONS: LA dysfunction was present in more than one third of AF patients after satisfactory rhythm control for > 3 months. Patients with higher burden (three or more) of clinical risk factors were more likely to have impaired LA function.     

Effect of elevated left ventricular diastolic filling pressure on the frequency of left atrial appendage thrombus in patients with nonvalvular atrial fibrillation

We investigated the relation between left ventricular diastolic dysfunction and left atrial appendage (LAA) thrombus in patients with atrial fibrillation (AF). We performed transesophageal echocardiography to examine LAA thrombus or spontaneous echo contrast (SEC) and to measure LAA emptying flow velocity in consecutive 376 patients with AF. We estimated diastolic filling pressure as the ratio of early transmitral flow velocity (E) to mitral annular velocity (e') on transthoracic echocardiogram. E/e' ratio in 28 patients (7.4%) with LAA thrombi was higher than that in patients without thrombus (18.3 ± 9.3 vs 11.4 ± 5.9, p <0.0001). The fourth quartile of E/e' (>13.6) consisted of 19 patients with thrombi and had a higher prevalence of thrombi than the others (p <0.0001). Multivariate regression analysis selected E/e' ≥13 as an independent predictor of LAA thrombus with an odds ratio of 3.50 (1.22 to 10.61) in addition to LA dimension and ejection fraction. Increased quartile of E/e' was negatively associated with LAA flow velocity and positively with rate of SEC. In conclusion, increased diastolic filling pressure is associated with a higher rate of LAA thrombus in AF, partly through blood stasis or impaired LAA function.     

Early predictors of alterations in left atrial structure and function related to left ventricular dysfunction in asymptomatic patients with hypertension

Our aim was to investigate the relationships between left atrial (LA) structural and functional changes and left ventricular (LV) dysfunction related to LV pressure overload in asymptomatic patients with hypertension. One hundred and twenty-six asymptomatic patients with hypertension and LV ejection fraction (EF) ≥60% were studied. Conventional, pulsed and tissue Doppler, and two-dimensional speckle-tracking echocardiography (2DSTE) were performed to seek the independent determinants for alterations in LA structure and function. LA volume index (LAVI) correlated with age, body mass index (BMI), end-diastolic ventricular septal thickness (VSth), end-diastolic LV posterior wall thickness, relative LV wall thickness (RWT), LV mass index, peak A velocity of transmitral flow, E/e’, and peak systolic and early diastolic LA strains and strain rates. Peak LA strain during ventricular systole (S-LAs) correlated with age, BMI, heart rate (HR), end-systolic LV diameter, LAVI, VSth, RWT, LVEF, e’, E/e’, peak systolic LV radial strain, and peak early diastolic LV longitudinal strain rate. Multivariate regression analyses indicated that LV mass index, peak A velocity, E/e’, and S-LAs are defined as strong predictors related to LAVI, and that BMI, HR, LAVI, and peak systolic LV radial strain are defined as strong predictors related to S-LAs. In conclusion, 2DSTE demonstrated that alterations in LA structure and function are mainly associated with LV diastolic and systolic dysfunction, respectively, in preclinical patients with hypertension.     

Atrial contraction after surgical isolation of the left atrial posterior wall concomitant with mitral valve replacement.

BACKGROUND: Surgical isolation of the left atrial posterior wall (LA-PW isolation) can terminate chronic atrial fibrillation associated with mitral valve disease. However, atrial contraction after LA-PW isolation has not been evaluated. METHODS AND RESULTS: The study group comprised 14 patients (mean age, 63+/-14 years) with mitral valve disease who recovered and maintained regular sinus rhythm after LA-PW isolation. Before the procedure, and 2-3 weeks and 1 year after the LA-PW isolation, the patients underwent an echocardiographic study. The left atrial (LA) diameter decreased after the LA-PW isolation and the change became significant 1 year later (before: 50.1+/-5.1 mm, after 2-3 weeks: 46.0+/-4.9 mm; p<0.05, after 1 year: 44.0+/-6.1 mm; p<0.05 vs before the operation). The left ventricular (LV) end-diastolic diameter, LV ejection fraction and LV fractional shortening did not change significantly from before the LA-PW isolation and after 1 year. The time - velocity integral of the atrial wave (Ai) and atrial filling fraction significantly increased (Ai: 4.5+/-2.1 cm vs 5.8+/-2.3 cm; p<0.05; atrial filling fraction: 15.4+/-7.7% to 19.2+/-8.3%; p<0.05) during the follow-up period. CONCLUSION: LA-PW isolation can benefit the restoration of regular sinus rhythm and, furthermore, the recovery of atrial contraction.     

Effects of captopril on left ventricular systolic and diastolic function after acute myocardial infarction.

The left ventricle progressively dilates in some patients after acute myocardial infarction (AMI). Both systolic and diastolic left ventricular (LV) dysfunction can be of significance in the development of heart failure. Captopril has been shown to prevent dilatation, but the effect on LV diastolic function is unknown. In a placebo-controlled double-blind parallel study, 58 AMI patients with heart failure or low ejection fraction, or both, were consecutively randomized at day 7 to either placebo or captopril (25 mg twice daily). No differences were present between the groups at baseline. Fifty-three patients completed the 6-month study period. Both LV diastolic and systolic volume indexes increased significantly in the placebo group (17 and 14%, respectively); in the captopril group there was no change in LV diastolic volume index, but a 13% reduction in LV systolic volume index. Ejection fraction increased significantly in the captopril group. The peak flow velocities of the early and atrial filling phases were measured, and the ratio between the velocities was calculated. A significant reduction was observed during the study period in early peak flow velocity (65 to 52 cm/s) and in the ratio between early and atrial peak flow velocity (1.3 to 0.8) in the placebo group (p less than 0.05), but no significant changes occurred in the captopril group. No correlation was found between dilatation of the left ventricle and reduction in early peak flow velocity or the ratio between early and atrial peak flow velocity. In conclusion, captopril prevented LV dilatation, improved ejection fraction and prevented LV diastolic dysfunction in AMI patients with early signs of LV systolic dysfunction.     

Right ventricular dysfunction in chronic heart failure patients

AIM: To evaluate any differences in haemodynamic and echocardiographic parameters in patients with both left (LV) and right ventricular (RV) systolic dysfunction and in patients with isolated LV systolic dysfunction. STUDY GROUP: One hundred patients with RV systolic dysfunction defined as peak velocity of tricuspid annular motion in systole (Sa)<11.5 cm/s, and 55 patients without RV systolic dysfunction Sa>11.5 cm/s. All patients had LV systolic dysfunction, LV ejection fraction (EF) below 40%, NYHA II-IV. METHODS: LV diameters, volumes and EF were measured by echocardiography. Patients underwent tissue Doppler imaging (TDI) of tricuspid annular motion with measurement of peak systolic velocity (Sa), peak early (Ea) and peak late (Aa) diastolic velocities. Right heart catheterization was also performed. RESULTS: Patients with RV systolic dysfunction did not differ from those without RV systolic dysfunction in terms of LV function. Patients with RV systolic dysfunction had larger RV dimension 30.6+/-5.8 vs. 33.9+/-6.7 mm, p<0.002. The patients with RV systolic dysfunction had higher values on right heart catheterization: MPAP 29.6+/-12.1 vs. 24.9+/-11.4 mm Hg, p<0.02, PCWP 20.8+/-10.0 vs. 17.3+/-9.3 mm Hg, p<0.03, PVR 189.9+/-123.3 vs. 137.7+/-94.9 dyn s cm(-5), p<0.008, CVP 7.7+/-5.6 vs. 5.1+/-3.9 mm Hg, p<0.002. The patients with RV systolic dysfunction had more pronounced diastolic dysfunction measured by TDI: Ea 9.9+/-2.3 vs. 11.4+/-2.5 cm/s, p<0.0001 and Aa 13.1+/-4.0 vs. 16.5+/-4.7 cm/s, p<0.000007. CONCLUSION: Patients with heart failure and both left and right ventricular systolic dysfunction showed more serious findings on central haemodynamics as well as more pronounced right ventricular diastolic dysfunction than those with isolated left ventricular systolic dysfunction.     

Doppler echocardiographic evaluation of left ventricular diastolic filling in isolated valvular aortic stenosis

Doppler echocardiography was used to study left ventricular (LV) diastolic filling in 49 adults with isolated aortic stenosis (AS), selected from 155 consecutive patients with AS by excluding coexisting mitral disease (n = 41) and/or significant aortic regurgitation (n = 80). There were no differences between patients with AS and age-matched normal subjects for early diastolic filling (E) velocity (68 +/- 17 vs 67 +/- 13 cm/s), late diastolic filling (A) velocity (79 +/- 25 vs 67 +/- 21 cm/s), E/A ratio (1.00 +/- 0.78 vs 1.06 +/- 0.32) or early diastolic deceleration slope (264 +/- 151 vs 319 +/- 137 cm/s2, differences not significant for all). There was no correlation between any LV filling parameter and AS severity, but late diastolic filling velocity was higher in patients with AS who had LV hypertrophy (n = 33) vs those who did not (n = 16) (86 +/- 23 vs 65 +/- 26 cm/s, p less than 0.01). In the patients with AS and systolic dysfunction (LV ejection fraction less than 50%) (n = 6), early diastolic filling velocity was higher (88 +/- 20 vs 65 +/- 15 cm/s, p less than 0.01), late diastolic filling velocity lower (53 +/- 23 vs 83 +/- 23 cm/s, p less than 0.01), E/A ratio higher (2.20 +/- 1.80 vs 0.84 +/- 0.28, p less than 0.01), deceleration slope steeper (439 +/- 230 vs 240 +/- 121 cm/s2, p = 0.02) and LV end-diastolic pressure higher (23 +/- 9 vs 10 +/- 6 mm Hg, p less than 0.01) than in patients with AS and normal systolic function.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Effect of cardiac resynchronization therapy on left atrial appendage function and pulmonary venous flow pattern

BACKGROUND: Previous studies have shown improvement in left ventricular function and development of the reverse remodeling in the left ventricle and left atrium after cardiac resynchronization therapy (CRT). The aim of this study was to investigate the effect of CRT on left atrial appendage (LAA) function and pulmonary venous flow pattern. METHODS: Eighteen patients with systolic heart failure and complete left bundle branch block underwent implantation of biventricular pacemaker devices. In order to follow changes in LAA, transthoracic and transesophageal echocardiographic examinations were performed 1 week before and repeated 1 and 6 months after pacemaker implantation. RESULTS: CRT resulted in significant clinical improvement and decrease in NYHA functional class in 17 patients (94%). Maximum and minimum areas of left atrial appendage (LAAAmax and LAAAmin) decreased, with a concomitant increase in LAA ejection fraction. [LAAAmax: from 4.6+/-2 to 4.2+/-1.8 cm2 at the first (P < 0.001) and to 4.0+/-1.8 cm2 at the sixth month (P < 0.001); LAAAmin: from 2.7+/-1.3 to 2.3+/-1.2 cm2 at the first (P < 0.001) and to 2.2+/-1.2 cm2 at the sixth month (P < 0.001) and LAA ejection fraction: from 41+/-12% to 46+/-10% at the first (P = 0.007) and to 47+/-8% at the sixth month (P = 0.003)]. LAA active emptying and filling flow and pulmonary venous systolic velocities also increased after CRT. The appendage active emptying velocity correlated significantly with left ventricular ejection fraction (r = 0.50, P = 0.002), LAA ejection fraction (r = 0.51, P = 0.002), left atrial maximal volume, LAVmax (r = -0.44, P = 0.007), left atrial minimal volume, LAVmin (r = -0.50, P = 0.002) and pulmonary vein systolic flow velocity (r = 0.33, P = 0.05). CONCLUSION: Treatment of heart failure by CRT results with marked improvements in LAA function and increases pulmonary venous systolic velocity.     

Assessment of left atrial appendage function by transesophageal echocardiography. Implications for the development of thrombus

BACKGROUND. The predilection of the left atrial appendage (LAA) for thrombus formation has long been known. METHODS AND RESULTS. We prospectively studied the two-dimensional echocardiographic and Doppler patterns of LAA function in 82 patients by transesophageal echocardiography. In the 63 patients in sinus rhythm, LAA area was measured during LAA diastole at the onset of the electrocardiographic (ECG) P wave (LAAmax) and after LAA systole at the ECG R wave (LAAmin) and LAA ejection fraction was calculated as (LAAmax-LAAmin)/LAAmax; peak Doppler velocity was recorded from the LAA outlet. The 58 patients in sinus rhythm without LAA thrombus were grouped according to left atrial size on transthoracic echocardiography; 39 patients had a left atrial size of less than 40 mm (group 1) and 19 had a left atrial size of 40 mm or greater (group 2). Five patients in sinus rhythm had LAA thrombus. In the 19 patients with atrial fibrillation or flutter LAAmax was measured independent of the ECG; three of these patients had LAA spontaneous contrast, four had thrombus, and one had both. Patients in sinus rhythm without LAA thrombus demonstrated a characteristic pattern of a contractile LAA apex and a noncontractile base with color flow and pulsed Doppler evidence of LAA emptying that coincided with the P wave. Patients in sinus rhythm with LAA thrombus had a mean +/- SD LAAmax (8.0 +/- 1.5 cm2) larger than that in group 1 (5.0 +/- 1.9 cm2) (p less than 0.01) but not group 2 (6.7 +/- 3.1 cm2), LAAmin (6.5 +/- 1.0 cm2) larger than that in both group 1 (2.3 +/- 1.5 cm2) and group 2 (4.2 +/- 2.7 cm2) (p less than 0.01), and LAA ejection fraction (17 +/- 11%) and LAA velocity (0.24 +/- 0.10 m/sec) less than those in both group 1 (55 +/- 21% and 0.48 +/- 0.24 m/sec, respectively) and group 2 (45 +/- 27% and 0.46 +/- 0.24 m/sec, respectively) (p less than 0.01). Patients with atrial fibrillation or flutter with LAA spontaneous contrast and/or thrombus had LAAmax (10.4 +/- 6.6 cm2) greater than that in patients with atrial fibrillation or flutter without LAA contrast and/or thrombus (6.8 +/- 3.0 cm2) (p less than 0.05). The LAA appeared as a static pouch in seven of eight of the former compared with in two of 11 of the latter. When attempted, Doppler demonstrated a recognizable fibrillatory LAA outflow velocity pattern in none of three in the former versus four of seven in the latter group. CONCLUSIONS. We conclude that the LAA has a characteristic pattern of emptying in sinus rhythm. LAA thrombus formation in sinus rhythm and atrial fibrillation is associated with both poor LAA contraction and LAA dilation.     

Pulmonary venous flows reflect changes in left atrial hemodynamics during mitral balloon valvotomy

Patients with mitral stenosis have usually blunted pulmonary venous (PV) flow, because of decreased mitral valve area and diastolic dysfunction. The authors compared changes in Doppler PV velocities by using transesophageal echocardiography (TEE) against hemodynamics parameters before and after mitral balloon valvotomy to observe relevance of PV velocities and endsystolic left atrial (LA) pressure-volume relationship. In 25 patients (aged 35 +/- 17 years) with mitral stenosis in sinus rhythm, changes in LA pressure and volumes were compared with PV velocities before and after valvotomy. Mitral valve area, mitral gradients, and deceleration time were obtained. Mitral valve area and mitral gradients changed from 1 +/- 0.2 cm2 and 14.6 +/- 5.4 mmHg to 1.9 +/- 0.3 cm2 and 6.3 +/- 1.7 mmHg, respectively (p<0.001). AR peak reverse flow velocity and AR duration decreased from 29 +/- 13 cm/s and 110 =/- 30 msec to 19 +/- 6 cm/s and 80 +/- 29 msec respectively (p<0.001). Transmitral Doppler E wave deceleration time decreased from 327 +/- 85 to 209 +/- 61 s and cardiac output increased from 4.2 +/- 1.0 to 5.2 +/- 1.1 L/minute (p<0.001). The changes in LA pressure were correlated with changes in S/D (r=0.57, p<0.05). The changes in endsystolic LA pressure-volume relationship were also correlated with changes in S/D (r=0.52, p<0.05). Endsystolic LA pressure-volume relationship decreased after mitral balloon valvotomy, as a result of a large decrease in pressure. PV systolic/diastolic (S/D) waves ratio reflects endsystolic LA pressure-volume relationship and may be used as another indicator of successful valvotomy.     

Left atrial appendage function and pulmonary venous flow in patients with nonrheumatic atrial fibrillation and their relation to spontaneous echo contrast

This study analyzed the relation between frequency of left atrial appendage (LAA) contractions, pulmonary venous flow (PVF) parameters, and spontaneous echo contrast (SEC). Thirty-six patients (22 male, 14 female, mean age 61 plus minus 11 years) with nonrheumatic atrial fibrillation undergoing transesophageal echocardiography were studied. Doppler flow was obtained from both the LAA and the left upper pulmonary vein. Fourier analysis was applied to the LAA signal that exhibited the frequency of LAA contractions. LAA emptying velocity and PVF parameters were determined. There was no relation between velocity and frequency of LAA flow (r = 0.256, P = ns). Among LAA and PVF parameters, patients with left atrial SEC (n = 17) had a lower LAA velocity (16.8 +/- 10.8 cm/sec vs 35.6 +/- 13.2 cm/sec, P < 0.001), a larger LAA area (4.8 +/- 2.2 cm(2) vs 3.0 +/- 1.3 cm(2), P = 0.008), and a reduced systolic velocity time integral of PVF (3.4 +/- 2.2 cm vs 5.4 +/- 2.2 cm, P = 0.017) when compared with patients without SEC. Frequency of LAA contractions was similar between both groups (6.8 +/- 0.4 Hz vs 6.8 +/- 1.0 Hz, P = ns). In conclusion, the rate of LAA contraction does not correlate with LAA flow velocity and SEC. A low left atrial flow expressed by low LAA flow velocity and a reduction in systolic PVF is a major hemodynamic determinant for the occurrence of SEC.     

Effect of chronic afterload increase on left ventricular myocardial function in patients with congenital left-sided obstructive lesions

The effect of pressure-overloading distance on left ventricular (LV) function in patients with congenital aortic coarctation and aortic stenosis (AS) was investigated. LV long-axis motions were recorded using M-mode and tissue Doppler imaging (TDI) techniques in 46 consecutive patients with severe LV outflow tract obstruction (23 coarctation and 23 AS), and results were compared with those of 23 controls. TDI lateral and septal long-axis systolic velocities, early diastolic velocities, and M-mode systolic amplitudes were lower in patients with coarctation and AS than controls (lateral site long-axis systolic velocity 7.1 +/- 1.7 and 6.4 +/- 1.6 vs 9.7 +/- 1.7 cm/s, septal site long-axis systolic velocity 6.3 +/- 1.3 and 5.4 +/- 1.1 vs 7.7 +/- 1.3 cm/s; lateral site early diastolic velocity 10.5 +/- 2.2 and 8.2 +/- 2.6 vs 13.1 +/- 2.5 cm/s, septal site early diastolic velocity 7.4 +/- 1.9 and 6.0 +/- 1.8 vs 10.8 +/- 1.6 cm/s, lateral site M-mode systolic amplitude 1.4 +/- 0.2 and 1.3 +/- 0.2 vs 1.6 +/- 0.2 cm, septal site M-mode systolic amplitude 1.2 +/- 0.2 and 1.1 +/- 0.2 vs 1.4 +/- 0.2 cm, p <0.01 for all). Compared with patients with coarctation, those with AS had lower TDI velocities, higher early LV filling velocity/long-axis diastolic velocity ratios, and a higher prevalence of long-axis incoordination (p <0.05 for all) despite similar LV mass index, ejection fraction, and systolic wall stress. In conclusion, LV long-axis function is impaired in patients with a chronic increase in afterload. Worse deterioration in LV function and higher prevalence of long-axis incoordination independent of LV outflow resistance is seen in patients with proximally increased LV afterload (AS) compared with distal disease (aortic coarctation).     

Comparison of left atrial volume parameters in detecting left ventricular diastolic dysfunction versus tissue Doppler recordings

Because of diastolic coupling between the left atrium and left ventricle, we hypothesized that left atrial (LA) function mirrors the diastolic function of left ventricle. The aims of this study were to assess whether LA volume parameters can be good indexes of left ventricular diastolic dysfunction. Six hundred fifty-nine patients underwent cardiac catheterization and measurements of left ventricular filling pressure (LVFP). Echocardiographic examinations including tissue Doppler and LA volumes were also assessed. Ratio of early diastolic mitral inflow velocity to early diastolic mitral annular velocity and LVFP tended to increase after progression of diastolic dysfunction. The inverse phenomenon existed in LA ejection and LA distensibility. LA distensibility was superior to LA ejection fraction and early diastolic mitral inflow velocity/early diastolic mitral annular velocity for identifying LVFP >15 mm Hg (areas under receiver operating characteristic curve 0.868, 0.834, and 0.759, respectively) and for differentiating pseudonormal from normal diastolic filling (areas under receiver operating characteristic curve 0.962, 0.907, and 0.741, respectively). Multivariate logistic regression showed that LA ejection fraction and LA distensibility were associated significantly with the presence of pseudonormal/restrictive ventricular filling. In conclusion, LA volume parameters can identify LVFP >15 mm Hg and differentiate among patterns of ventricular diastolic dysfunction. For assessing diastolic function LA parameters offer better performance than even tissue Doppler.     

The effect of different atrioventricular delays on left atrium and left atrial appendage function in patients with DDD pacemaker

Background: Although it has been known that optimization of atrioventricular delay (AVD) has favorable effect on the left ventricular functions in patients with DDD pacemaker, the effect of different AVDs on left atrium (LA) and left atrial appendage (LAA) functions has not been exactly evaluated. The aim of the present study was to assess the effect of different AVDs on LA and LAA functions in DDD pacemaker implanted patients with atrioventricular block. Methods: Forty‐eight patients with DDD pacemaker were enrolled into the study. Patients were divided into two groups according to the echocardiographic diastolic function: Group I (normal diastolic function) and Group II (diastolic dysfunction). LAA emptying velocity on pulsed wave Doppler and LAA late systolic wave velocity by using tissue Doppler were recorded. Patients were paced for five successive continuous pacing periods of 10 minutes duration using five selective AVDs (80–250 ms). Results: Significant effect on LA and LAA functions has not been observed by the setting of AVD in Group I. However, when the AVD was gradually shortened form 150 ms to 80 ms, LA and LAA functions gradually decreased in Group II patients. When AVD increased to 200 ms, LA and LAA functions were improved. Further increase in AVD resulted in decreased LA and LAA functions. Conclusion: Setting of AVD has not significant effect on the LA and LAA functions in patients with normal diastolic function, but moderate prolongation of AVD in physiological limits improved LA and LAA functions in DDD pacemaker implanted patients with diastolic dysfunction. (Echocardiography 2011;28:626‐632)     

Patients with a hypertensive response to exercise have impaired left ventricular diastolic function

An exaggerated increase in systolic blood pressure prolongs myocardial relaxation and increases left ventricular (LV) chamber stiffness, resulting in an increase in LV filling pressure. We hypothesize that patients with a marked hypertensive response to exercise (HRE) have LV diastolic dysfunction leading to exercise intolerance, even in the absence of resting hypertension. We recruited 129 subjects (age 63+/-9 years, 64% male) with a preserved ejection fraction and a negative stress test. HRE was evaluated at the end of a 6-min exercise test using the modified Bruce protocol. Patients were categorized into three groups: a group without HRE and without resting hypertension (control group; n=30), a group with HRE but without resting hypertension (HRE group; n=25), and a group with both HRE and resting hypertension (HTN group; n=74). Conventional Doppler and tissue Doppler imaging were performed at rest. After 6-min exercise tests, systolic blood pressure increased in the HRE and HTN groups, compared with the control group (226+/-17 mmHg, 226+/-17 mmHg, and 180+/-15 mmHg, respectively, p<0.001). There were no significant differences in LV ejection fraction, LV end-diastolic diameter, and early mitral inflow velocity among the three groups. However, early diastolic mitral annular velocity (E') was significantly lower and the ratio of early diastolic mitral inflow velocity (E) to E' (E/E') was significantly higher in patients of the HRE and HTN groups compared to controls (E': 5.9+/-1.6 cm/s, 5.9+/-1.7 cm/s, 8.0+/-1.9 cm/s, respectively, p<0.05). In conclusion, irrespective of the presence of resting hypertension, patients with hypertensive response to exercise had impaired LV longitudinal diastolic function and exercise intolerance.