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PubMed1993

Impact of electrical cardioversion for atrial fibrillation on left atrial appendage function and spontaneous echo contrast: characterization by simultaneous transesophageal echocardiography.

OBJECTIVES: This study assessed the function of the left atrial appendage in the pericardioversion period to gain insights into mechanisms involved in thromboembolism after cardioversion of atrial fibrillation. BACKGROUND: Systemic embolization associated with electrical cardioversion of atrial fibrillation is thought to originate from the left atrium or left atrial appendage, or both. However, the mechanism involved is poorly understood. METHODS: We studied left atrial appendage function with transesophageal echocardiography in 20 patients with atrial fibrillation before and after successful electrical cardioversion. We measured left atrial appendage emptying and filling velocities by pulsed wave Doppler echocardiography, characterized Doppler emptying patterns, measured atrial appendage areas and assessed the presence or absence of spontaneous echo contrast or thrombus. RESULTS: Organized left atrial appendage function returned in 16 (80%) of 20 patients immediately after cardioversion. Atrial appendage emptying velocities before cardioversion were greater in patients without (0.39 +/- 0.02 m/s) than in those with (0.25 +/- 0.12 m/s) spontaneous echo contrast (p = 0.045). Furthermore, emptying velocities before cardioversion were significantly greater than late diastolic emptying velocities after cardioversion (0.31 +/- 0.15 vs. 0.14 +/- 0.12 m/s, p = 0.0001), as well as in both the group with (0.25 +/- 0.12 vs. 0.13 +/- 0.13 m/s, p = 0.001) and the group without (0.39 +/- 0.02 vs. 0.15 +/- 0.12 m/s, p = 0.01) spontaneous echo contrast. In addition, left atrial and atrial appendage spontaneous echo contrast developed in 4 of 20 patients and increased in intensity in 3 of 20 patients in the immediate postcardioversion period. CONCLUSIONS: Organized left atrial appendage function returns in most patients immediately after cardioversion of atrial fibrillation. However, its function is impaired compared with that before cardioversion. Furthermore, spontaneous echo contrast increased in 7 (35%) of 20 patients after cardioversion. These observations suggest that stunned left atrial appendage function after cardioversion may predispose the chamber to thrombus formation, which may play a role in the mechanism involved in the occurrence of embolization after cardioversion.

Aged↗
PubMedDate not supplied

Is functional capacity related to left atrial contractile function in nonobstructive hypertrophic cardiomyopathy?

The mechanisms underlying reduced exercise capacity in patients with nonobstructive hypertrophic cardiomyopathy (NHCM) could include perturbations of ventricular relaxation, diastolic compliance, or compensatory atrial systolic function. We hypothesized that a loss of atrial contractility in NHCM patients leads to reduced functional capacity. To test this hypothesis, we compared resting noninvasive left atrial ejection phase indices in 49 consecutive patients with NHCM (ages 36+/-10 years; 41% female) and normal left ventricular ejection fraction (mean, 68%+/-8%) with objective metabolic exercise parameters. Left atrial active emptying fraction, ejection force, and kinetic energy failed to predict exercise capacity. Only left atrial total and active emptying volumes correlated weakly with minute volume/CO2 production slope (r=0.31 and r=0.33; p<0.05 for both). Furthermore, when subjects were stratified by New York Heart Association symptomatology, exercise parameters--but not atrial contractility--differed between groups. These data, obtained at rest, fail to suggest that NHCM-related heart failure symptoms are due to an atrial myopathy.

Adult↗
PubMed1994

A study on left atrial transport function. Effect of age or left ventricular ejection fraction on left atrial storage fraction.

Left atrial (LA) storage fraction is defined as the ratio of storage volume of the left atrium (LA) during ventricular systole to left ventricular (LV) stroke volume. To test their hypothesis that left atrial (LA) storage fraction is increased to compensate for impaired LV filling in the heart of aged subjects or with impaired LV ejection fraction, the authors studied 33 "normal" subjects and 25 patients with coronary artery disease. LA volume was measured by LA cineangiocardiography, and LV stroke volume and LV ejection fraction were measured by LV cineangiocardiography. To further evaluate the determinants of changes in LA storage fraction, they measured the ratio of LA active release volume to LV stroke volume, and the ratio of LA passive release volume to LV stroke volume. In "normal" subjects, LA storage fraction was increased with age (r = 0.584, P < 0.01). In patients with coronary artery disease, LA storage fraction was increased as LV ejection fraction was decreased (r = -0.525, P < 0.01). In both cases, LA active release fraction was significantly associated with changes in LA storage fraction rather than in LA passive release fraction. They conclude that LA storage fraction may be an important determinant of LV filling mainly through the LA active release fraction.

Adolescent↗
PubMed2000

Noninvasive indexes of left atrial diastolic function in hypertrophic cardiomyopathy.

OBJECTIVES: Our goal was to noninvasively assess left atrial diastolic function and its relation to the impaired left ventricular filling in patients with hypertrophic cardiomyopathy. METHODS AND RESULTS: We studied 34 patients with hypertrophic cardiomyopathy, 26 patients with secondary forms of left ventricular hypertrophy (aortic stenosis, fixed subaortic stenosis, hypertension), and 21 control subjects. Left atrial diastolic function was assessed by measuring acceleration time (SAT), deceleration time (SDT), and the EF (mean deceleration rate) slope of the pulmonary venous flow systolic wave (SW). Left ventricular diastolic function assessed by transmitral Doppler included peak early left ventricular and peak atrial filling velocities, the ratio of early-to-late peak velocities, isovolumic relaxation time, deceleration time, and EF slope. In patients with hypertrophic cardiomyopathy, acceleration time was significantly reduced (P<.05), deceleration time was significantly prolonged (P<.0001), and EF slope was significantly reduced (P<.01). These indexes were similar among the other two groups. No statistically significant difference existed between the subgroups of hypertrophic cardiomyopathy in the above indexes. Patients with hypertrophic cardiomyopathy and secondary forms of left ventricular hypertrophy had evidence of left ventricular diastolic dysfunction. In patients with hypertrophic cardiomyopathy, no correlation existed between left atrial and left ventricular diastolic function indexes (r = -0.26 to 0.33). CONCLUSIONS: Echocardiographic indexes of left atrial relaxation and filling are abnormal in patients with hypertrophic cardiomyopathy but not in secondary forms of left ventricular hypertrophy. These indexes are abnormal in all forms of hypertrophic cardiomyopathy irrespective of left ventricular outflow tract obstruction and distribution of hypertrophy; they are not solely attributable to left ventricular diastolic dysfunction. The above may imply that hypertrophic cardiomyopathy is a cardiac myopathic disease that involves the heart muscle as a whole, irrespective of distribution of hypertrophy and obstruction.

Adolescent↗
PubMed2001

Left atrial systolic function in relation to electrical and mechanical remodeling in a canine model.

Rapid atrial activation causes electrical remodeling that promotes the occurrence and maintenance of atrial fibrillation. The aim of this research was to compare the relationship between mechanical remodeling and atrial electrophysiology. Eight dogs (beagles) were subjected to rapid atrial pacing (AP) at 400 beats/min for 16 days. After a complete recovery of electrical variables and left ventricular function evaluated by echocardiography, they underwent high-rate ventricular pacing (VP) at 240 beats/min of equal duration. In half of them, the study was started by VP and in the other half by AP. Left atrial systolic function was assessed by transesophageal echocardiography. Atrial effective refractory period (AERP) at a basic cycle length of 400 ms decreased significantly after either type of pacing (AP: 115 +/- 17 ms, VP: 136 +/- 22 ms) compared with baseline values (153 +/- 23 ms); the difference between tachycardias was significant too (p < 0.02). Significant increases (p < 0.05) in left atrial dimensions (LA-A) (AP: 2.41 +/- 0.23 cm ,VP: 2. 43 +/- 0. 34 cm vs. basal: 2. 16 +/- 0. 21 cm) indicated atrial dilatation after either type of pacing, the differences between two groups being insignificant. Atrial reversal pulmonary venous flow (AR velocity) decreased in AP (-0.13 +/- 0. 02 m/s) and VP (-0. 17 +/- 0. 04 m/s). The difference was highly significant as compared to basal values (-0.25 +/- 0.05 m/s) and also with respect to both tachycardias (p < 0.01). In both groups, atrial remodeling occurred in a relatively short period of time. The echocardiographic findings suggested that left atrial systolic function was significantly more disturbed in the AP group than in the VP group. Mechanical changes are an important substrate of electrical remodeling, yet the deterioration of electrical variables was more pronounced in AP than in VP.

Animals↗
PubMed1994

Assessment of left atrial appendage function by biplane transesophageal echocardiography in patients with nonrheumatic atrial fibrillation: identification of a subgroup of patients at increased embolic risk.

OBJECTIVES: This study was conducted to identify a subgroup of patients with nonrheumatic atrial fibrillation with an increased risk for cardiogenic embolism by assessing left atrial appendage function. BACKGROUND: Patients with nonrheumatic atrial fibrillation have an increased risk for thromboembolic complications. The left atrial appendage is the most likely source for thrombus formation. It is likely that the appendage function (contraction, filling dynamics) is related to the pathogenesis of thrombus formation. METHODS: Twenty-nine patients with nonrheumatic atrial fibrillation (group I) underwent biplane transesophageal echocardiography. The maximal and minimal areas during a cardiac cycle and the peak emptying and filling velocities of the appendage were measured in both scan planes. For comparison, two additional groups were also analyzed. Group II consisted of 12 patients with chronic atrial fibrillation due to significant mitral stenosis, and group III consisted of 30 patients who were in sinus rhythm. RESULTS: Patients with nonrheumatic atrial fibrillation showed two distinct appendage flow patterns: either well defined peak filling and emptying waves (> or = 25 cm/s) with visible fibrillatory contractions of the appendage wall ("high flow profile") or irregular, very low, peak filling and emptying waves (< 25 cm/s) associated with almost no visible appendage contractions ("low flow profile"). The left atrial appendage function in the first subgroup resembles that seen in patients with sinus rhythm, whereas the appendage function in the latter subgroup resembles more the "static pouch" seen in patients with rheumatic atrial fibrillation. Events suggestive of cardiogenic embolism occurred in six patients from group I, five of whom were in the low flow profile subgroup (p < 0.05). The spontaneous echo contrast phenomenon was observed in 80% of the low flow profile subgroup but in only 5% in the high flow profile subgroup (p < 0.05). Three thrombi confined to the left atrial appendage were detected by transesophageal echocardiography in group I; all three of the patients were in the low flow profile subgroup. CONCLUSIONS: The assessment of left atrial appendage function by transesophageal echocardiography may be helpful to identify subgroups of patients with nonrheumatic atrial fibrillation with an increased risk of thrombus formation.

Atrial Fibrillation↗
PubMed2005

Normal human left and right ventricular and left atrial dimensions using steady state free precession magnetic resonance imaging.

PURPOSE: The aim of this project was to establish a database of left and right ventricular and left atrial dimensions in healthy volunteers using steady-state free precession cardiac magnetic resonance imaging, the clinical technique of choice, across a wide age range. METHODS: 108 healthy volunteers (63 male, 45 female) underwent cardiac magnetic resonance imaging using steady-state free precession sequences. Manual analysis was performed by 2 experienced observers. RESULTS: Left and right ventricular volumes and left ventricular mass were larger in males than females: LV end-diastolic volume 160 +/- 29 mL vs. 135 +/- 26 mL, LV end-systolic volume 50 +/- 16 mL vs. 42 +/- 12 mL; RV end-diastolic volume 190 +/- 33 mL vs. 148 +/- 35 mL, RV end-systolic volume 78 +/- 20 mL vs. 56 +/- 18 mL (p < .05 for all). Normalization of values to body surface area removed the statistical differences for LV volumes, but not for LV mass or RV volumes. With increased age, males showed a significant decrease in volume and mass indices for both ventricles, while female values remained unchanged. Compared to females, males had significantly larger maximal left atrial volumes (103 +/- 30 mL vs. 89 +/- 21 mL, p = .01) and left atrial stroke volumes (58 +/- 23 mL vs. 48 +/- 15 mL, p = .01). There was no difference in left atrial ejection fraction between the sexes. CONCLUSION: We have produced a large database of age-related normal ranges for left and right ventricular function and left atrial function in males and females. This will allow accurate interpretation of clinical and research datasets.

Adult↗
PubMed1994

Left atrial appendage function and thrombus formation in atrial fibrillation-flutter: a transesophageal echocardiographic study.

OBJECTIVES: The purpose of this study was to investigate left atrial appendage size, function and thrombus prevalence in patients with atrial "fibrillation-flutter." BACKGROUND: Thrombus formation and peripheral embolization in atrial fibrillation are related to left atrial appendage dysfunction. Embolization occurs less frequently in atrial flutter. It is not known whether the atrial appendage in fibrillation-flutter, which has an intermediate appearance on the surface electrocardiogram (ECG), has distinct characteristics that could affect thrombus formation. METHODS: Sixty-one patients with atrial tachyarrhythmias underwent transesophageal echocardiographic examination of the left atrial appendage. Appendage area, peak emptying velocity and the presence of thrombus and spontaneous echo contrast were determined. The results for 14 patients with fibrillation-flutter (based on ECG fibrillatory wave characteristics) were compared with those for 30 patients with atrial fibrillation and 17 patients with atrial flutter. RESULTS: Both fibrillation-flutter and atrial fibrillation were associated with chaotic appendage flow patterns with similarly low peak emptying velocities (18 +/- 8 and 17 +/- 10 cm/s, mean +/- 1 SD, respectively). Atrial flutter was associated with a regular pattern of appendage contraction and a significantly higher peak emptying velocity (42 +/- 18 cm/s, p < 0.0001). Mean appendage area was similar for fibrillation-flutter and fibrillation (6.3 +/- 2.2 and 6.7 +/- 2.1 cm2, respectively) but was significantly smaller for atrial flutter (5.3 +/- 1.4 cm2, p < 0.05). The prevalence of left atrial appendage thrombus was similar for fibrillation-flutter and atrial fibrillation (40% and 29%, respectively), whereas no patient with atrial flutter had a thrombus (p < 0.05). Similarly, the presence of spontaneous echo contrast was higher for fibrillation-flutter (50%) and atrial fibrillation (40%) than for atrial flutter (6%, p < 0.05). CONCLUSIONS: Left atrial appendage size and function in atrial fibrillation-flutter are indistinguishable from those of typical atrial fibrillation, and the frequency of thrombus and spontaneous echo contrast is similarly high. This is in contrast to atrial flutter, which is characterized by a smaller, more contractile left atrial appendage and a lower frequency of thrombus and spontaneous echo contrast.

Aged↗
PubMed2004

Left atrial systolic function in primary and familial amyloidosis: assessment from left atrial volume change.

The severity of left ventricular involvement may differ between primary (PA) and familial amyloidosis (FA). This study examined whether differences in left atrial (LA) systolic function are also present. Twenty-eight patients (18 men, 10 women, aged 59 +/- 12 years) with PA, 17 (11 men, 6 women, aged 40 +/- 11 years) with FA, and 25 normal controls (18 men, 7 women, aged 56 +/- 14 years) underwent transthoracic M-mode, two-dimensional, and Doppler echocardiography. Left atrial volumes were determined at mitral valve (MV) opening (maximal, Vmax), electrocardiographic P wave (onset of atrial systole, Vp), and MV closure (minimal, Vmin) from the apical two-and four-chamber views using the biplane area-length method. Left atrial systolic function was assessed with the LA active emptying volume (ACTEV) = Vp-Vmin and fraction (ACTEF) = ACTEV/Vp. The E/A ratio was increased (1.34 +/- 0.93 vs. 0.89 +/- 0.3), whereas deceleration time was decreased (168.1 +/- 33.7 vs. 196.2 +/- 34.2 ms) in PA compared with FA (p<0.05). Vmax and Vp were similar in PA and FA and greater than in the controls (46.6 +/- 14 vs. 40 +/- 11.4 vs. 27.1 +/- 6.3 cm3/m2, p<0.01, and 33.4 +/- 11.6 vs. 29.7 +/- 10.8 vs. 16.8 +/- 3.8 cm3/m2, p<0.01, respectively). The ACTEV was lower in PA and in the controls than in FA (6.7 +/- 2 vs. 6.2 +/- 2.2 vs. 8.5 +/- 3.3, respectively, p<0.05). The ACTEF was lower in PA than in FA and both were lower than those in the controls (20 +/- 5% vs. 28 +/- 7% vs. 36 +/- 11%, respectively, p<0.01). Despite a similar increase in LA volume, LA systolic dysfunction is more pronounced in PA than in FA. This is most likely due to the restrictive left ventricular physiology possibly associated with depressed LA contractility in the former.

Adult↗
PubMed2004

Color Doppler tissue imaging to evaluate left atrial appendage function in patients with mitral stenosis in sinus rhythm.

Two-dimensional color Doppler tissue imaging (CDTI) has so far been used, in general, to evaluate ventricular function. In this study, the left atrial appendage (LAA) tissue velocity was measured by CDTI. LAA function in 38 patients with mitral stenosis in sinus rhythm (SR) and 19 healthy subjects undergoing transesophageal echocardiography were examined by CDTI. Systolic tissue appendage velocity (SaV, m/s) was measured at the tip of the LAA in the basal short-axis view. LAA emptying (LAAEV) and filling (LAAFV) velocities (m/s) were also recorded 1 cm below the orifice of the appendage. LAA ejection fraction was also measured. In addition, two-dimensional imaging was used to determine the presence of thrombus and/or spontaneous echo contrast (SEC). Patients with mitral stenosis in SR had significantly decreased LAAEV, LAAFV, SaV, and LAA ejection fraction compared to controls (0.34 +/- 0.15 vs 0.72 +/- 0.17, 0.37 +/- 0.13 vs 0.63 +/- 0.19, 0.050 +/- 0.015 vs 0.071 +/- 0.093, and 39 +/- 14% vs 69 +/- 13%, respectively, P < 0.001, P < 0.001, P < 0.001, and P < 0.001). Among the patients with mitral stenosis in SR, 10 patients had SEC and one had LAA thrombus. Compared with patients without SEC, patients with SEC had decreased LAAEV, LAAFV, SaV, and LAA ejection fraction (0.24 +/- 0.05 vs 0.37 +/- 0.16, 0.29 +/- 0.05 vs 0.39 +/- 0.14, 0.039 +/- 0.087 vs 0.055 +/- 0.015, and 28 +/- 14% vs 43 +/- 12%, respectively, P = 0.01, P = 0.02, P = 0.01, and P = 0.006). In conclusion, these results suggest that the LAA dysfunction may occur in patients with mitral stenosis in SR and CDTI can successfully be used for the quantification of contraction at the tip of the LAA.

Adult↗
PubMed2004

A rapid method to quantify left atrial contractile function: Doppler tissue imaging of the mitral annulus during atrial systole.

AIMS: Assess the value of peak atrial systolic mitral annular velocity (Aann) measured by Doppler tissue echocardiography to quantify left atrial systolic function. METHODS: We studied a total of 61 adults; 10 subjects without history of heart disease and 51 patients with a history of atrial fibrillation or undergoing evaluation for left ventricular systolic or diastolic dysfunction. Aann was obtained by averaging peak atrial systolic mitral annular velocities from the septal, lateral, anterior, and inferior annulus. Left atrial fractional area change (FAC) and fractional volume change (FVC) during atrial systole were calculated. The correlation between peak atrial systolic mitral annular velocity (Aann) and left atrial systolic FAC and FVC was determined. RESULTS: Mean FAC and FVC were 27 +/- 12 and 40 +/- 14%, respectively; mean Aann was 11.2 +/- 3.2 cm/s. Linear regression analysis showed correlation between Aann and FAC (r = 0.71; p<0.001) and between Aann and FVC (r = 0.74; p<0.001). CONCLUSIONS: Peak systolic mitral annular velocity correlates well with left atrial systolic FAC and FVC, thus providing an easy means to assess left atrial systolic function.

Adult↗
PubMed2000

Clinical and echocardiographic characteristics of left atrial spontaneous echo contrast in sinus rhythm.

OBJECTIVES: In this study we attempt to define the clinical and echocardiographic characteristics of patients with left atrial spontaneous echo contrast (LASEC) in sinus rhythm (NSR). BACKGROUND: Left atrial spontaneous echo contrast in atrial fibrillation (AF) is associated with increased risk of thromboembolism. Little is known about its significance in NSR. METHODS: We reviewed reports of 1,288 transesophageal echocardiogram (TEE) studies done with a 5 MHz probe. Patients with swirling LASEC who were in NSR during TEE were analyzed. We compared them with a control group of 45 age matched patients selected to have NSR, left atrium (LA) > 4.0 cm but no SEC. RESULTS: Spontaneous echo contrast in NSR was noted in 24 patients (2%) and formed our study group. All patients with SEC had enlarged LA, mean 5.6 cm +/- 0.6 cm. There was a higher prevalence of cerebrovascular accident (CVA) in patients with SEC when compared with controls with no SEC, 83% versus 56%, p = 0.02. Patients with SEC had larger LA, 5.6 versus 4.9 cm, p < 0.0001 and lower mean peak left atrial appendage emptying velocity (LAAEV), 38 versus 56 cm/s, p = 0.001. Thirteen percent of patients with SEC had LA thrombus as compared with none in the control group, p = 0.02. By multivariate analysis, SEC in NSR was found to be associated with CVA, larger LA size and decreased mean LAAEV. Even after adjusting for LA size, patients with SEC had a higher prevalence of CVA than controls, p = 0.03. CONCLUSIONS: Spontaneous echo contrast in NSR occurs in patients with significantly dilated LA and depressed atrial function. Left atrial thrombus is noted in 13% of such patients despite NSR. Spontaneous echo contrast in NSR is associated with a higher prevalence of CVA. Further, SEC is found to be an independent and more powerful correlate of CVA than reduced LAAEV or atrial size. These data indicate that LASEC in NSR is a prothombotic condition.

Aged↗
PubMed1995

Clinical significance of fibrillatory wave amplitude. A clue to left atrial appendage function in nonrheumatic atrial fibrillation.

Seventy-eight patients with chronic nonrheumatic atrial fibrillation were studied by transesophageal echocardiography with regard to the left atrial appendage function and its relation to the coarseness of atrial fibrillation on electrocardiogram. These 78 patients (52 men and 26 women; mean age, 66 +/- 10 years; range, 40 to 94 years) were classified into two groups according to the presence of coarse (group 1, n = 46; those with the greatest amplitude of fibrillatory wave in lead V1 > or = 1 mm) or fine (group 2, n = 32; those without the coarse fibrillatory wave in lead V1) atrial fibrillation on a standard 12-lead electrocardiogram within 1 month of echocardiographic studies. There were no significant differences in age, sex, mean duration of atrial fibrillation, left ventricular end-diastolic dimension, left ventricular end-systolic dimension, left ventricular ejection fraction, and left atrial dimension between the two groups. In group 1, however, the left atrial appendage ejection fraction (24.4 +/- 14.2% vs 32.6 +/- 14.8%; p < 0.05) and the peak emptying velocity (21.7 +/- 12.6 cm/s vs 30.4 +/- 14.3 cm/s; p < 0.01) were lower than those in group 2. There were higher incidences of left atrial appendage spontaneous echo contrast (26/46 vs 7/32; p < 0.005) and thrombus (8/46 vs 0/32; p < 0.05) in group 1 patients. The coarse atrial fibrillation revealed a sensitivity of 80.0%, a specificity of 58.1%, a positive predictive value of 60.9%, and a negative predictive value of 78.1% for the presence of left atrial appendage spontaneous echo contrast and/or thrombus formation. In conclusion, in patients with coarse nonrheumatic atrial fibrillation, the left atrial appendage function is usually poor and the incidence of spontaneous echo contrast and thrombus formation appears to be higher in these patients.

Adult↗
PubMed2004

Response of B-type natriuretic peptide to exercise in hypertensive patients with suspected diastolic heart failure: correlation with cardiac function, hemodynamics, and workload.

BACKGROUND: Diastolic heart failure (DHF) is characterized by dyspnea due to increased left ventricular (LV) filling pressures during stress. We sought the relationship of exercise-induced increases in B-type natriuretic peptide (BNP) to LV filling pressures and parameters of cardiovascular performance in suspected DHF. METHODS: Twenty-six treated hypertensive patients with suspected DHF (exertional dyspnea, LV ejection fraction >50%, and diastolic dysfunction) underwent maximal exercise echocardiography using the Bruce protocol. BNP, transmitral Doppler, and tissue Doppler for systolic (Sa) and early (Ea) and late (Aa) diastolic mitral annular velocities were obtained at rest and peak stress. LV filling pressures were estimated with E/Ea ratios. RESULTS: Resting BNP correlated with resting pulse pressure (r=0.45, P=0.02). Maximal exercise performance (4.6 +/- 2.5min) was limited by dyspnea. Blood pressure increased with exercise (from 143 +/- 19/88 +/- 8 to 191 +/- 22/ 90 +/- 10 mm Hg); 13 patients (50%) had a hypertensive response. Peak exercise BNP correlated with peak transmitral E velocity (r = 0.41, P <.05) and peak heart rate (r = -0.40, P <.05). BNP increased with exercise (from 48 +/- 57 to 74 +/- 97 pg/mL, P =.007), and the increment of BNP with exercise was associated with maximal workload and peak exercise Sa, Ea, and Aa (P <.01 for all). Filling pressures, approximated by lateral E/Ea ratio, increased with exercise (7.7 +/- 2.0 to 10.0 +/- 4.8, P <.01). BNP was higher in patients with possibly elevated filling pressures at peak exercise (E/Ea >10) compared to those with normal pressures (123 +/- 124 vs 45 +/- 71 pg/mL, P =.027). CONCLUSIONS: Augmentation of BNP with exercise in hypertensive patients with suspected DHF is associated with better exercise capacity, LV systolic and diastolic function, and left atrial function. Peak exercise BNP levels may identify exercise-induced elevation of filling pressures in DHF.

Atrial Function, Left↗
PubMed1997

[Is reduced left ventricular volume related to mechanisms of dynamic mid-ventricular obstruction provoked by dobutamine infusion?].

Forty-seven patients with unexplained chest pain and normal resting echocardiograms were examined to see whether dynamic mid-ventricular obstruction (MVO) is induced by dobutamine infusion. Dynamic MVO was provoked in 17 patients (MVO group), but not in the other 30 patients (Non-MVO group). Before dobutamine infusion, the blood pressure in the MVO group was higher than that in the Non-MVO group (p < 0.05), but end-diastolic volume index (p < 0.001), end-systolic volume index (p < 0.01), stroke volume index (p < 0.001), cardiac index (p < 0.001), end-diastolic volume (p < 0.01) and end-systolic volume (p < 0.05) of the apical territory of the left ventricle in the MVO group were significantly less than those in the Non-MVO group. The left atrial function, left ventricular ejection fraction and ejection fraction of the apical territory of the left ventricle did not differ between the groups. Seven patients in the MVO group were re-examined by dobutamine stress echocardiography after beta-blocker administration, showing that the dynamic MVO was completely suppressed. The end-diastolic volume tended to increase after beta-blocker administration, but no significant difference was found in any other variables except heart rate. The results suggest that a smaller left ventricle and higher blood pressure are important characteristics in patients with dobutamine-induced dynamic MVO, and additionally, the difference in local myocardial contractility may be an important cause of the induction of dynamic MVO.

Adrenergic beta-Agonists↗
PubMed2003

Fibrillatory wave amplitude as a marker of left atrial and left atrial appendage function, and a predictor of thromboembolic risk in patients with rheumatic mitral stenosis.

BACKGROUND: Patients with mitral stenosis, especially those with atrial fibrillation, are at increased risk for thromboembolic complications. Size of the left atrium, left atrial appendage dysfunction and severity of mitral stenosis are known risk factors for thromboembolism in patients with mitral stenosis. It has been postulated that F-wave amplitude on surface ECG is correlated with left atrial size, left atrial appendage function, and risk of thromboembolism in patients with nonrheumatic atrial fibrillation. The aims of this study were as follows: (1) to examine the relationship between surface ECG F-wave amplitude and left atrial appendage function, and (2) to assess the clinical significance of F-wave amplitude as it relates to risk of thromboembolism in a group of patients with rheumatic mitral stenosis. MATERIAL AND METHODS: One hundred patients with rheumatic mitral stenosis and permanent atrial fibrillation but without moderate to severe mitral insufficiency were investigated by transthoracic and transesophageal echocardiography. Two groups were formed according to the presence of a coarse (Group 1; n=60; F-wave in lead V1> or =1 mm) or fine (Group 2; n=40; F-wave in lead V1<1 mm) F-wave on surface ECG. RESULTS: Comparison showed that Group 1 had significantly smaller mitral valve area (1.44+/-0.6 versus 1.7+/-0.74 cm2, respectively; P<0.05), lower peak left atrial appendage flow velocity (18.8+/-2.1 versus 25.6+/-1.9 cm/s, respectively; P<0.005), higher-grade spontaneous echo contrast (2.05+/-1.44 versus 0.98+/-1.14, respectively; P<0.0001), and higher prevalence of thromboembolism (35% versus 12.5%, respectively; P<0.012). Multiple logistic regression analysis revealed that mitral valve area, left atrial appendage peak velocity, and coarse F-wave were independent clinical risk factors for thromboembolism in this patient group. CONCLUSION: The data suggest that presence of a coarse F-wave on surface ECG is associated with left atrial appendage dysfunction, and indicates higher thromboembolic risk in patients with predominant rheumatic mitral stenosis.

Adolescent↗
PubMed1998

Left atrial appendage function assessed by transesophageal echocardiography before and on the day after elective cardioversion for nonvalvular atrial fibrillation.

We investigated left atrial appendage function by transesophageal echocardiography, on the day after external electrical cardioversion to sinus rhythm, in 41 patients with nonvalvular atrial fibrillation. After cardioversion, appendage contraction synchronized with the electrical and mechanical activity of the atrium, which was restored in about 70% of the patients.

Adult↗
PubMed2006

Early effects of percutaneous mitral valvuloplasty on left atrial mechanical functions.

It has been suggested that successful percutaneous balloon mitral valvuloplasty (PMV) decreases the intensity of spontaneous left atrial contrast, reduces the size of the left atrium, and improves left atrial function in patient with mitral stenosis. However, left atrial mechanical functions immediately after PMV have not been extensively evaluated yet. The aim of this study was to evaluate the effects of PMV on left atrial mechanical functions. Twenty patients with critical mitral stenosis who have normal sinus rhythm (male/female: 4 to 16; mean age: 33 +/- 8 years) were included in the study. Left atrial mechanical functions were evaluated before and after PMV, including left atrial passive emptying volume, LA passive emptying fraction, conduit volume, left ventricular stroke volume, LA active emptying volume, LA active emptying fraction, LA total emptying volume and LA total emptying fraction. PMV resulted in a significant increase in the mitral valve area (p < 0.001) and a substantial reduction in the mean transmitral pressure gradient (p < 0.001) as well as LA diameter (p < 0.002). LA maximal volume, minimal volume and atrial presystolic volumes were significantly decreased after PMV (p: 0.001; p: 0.002; p: 0.001, respectively). The conduit volume was increased and LA total emptying volume was decreased after PMV (p: 0.014; p: 0.035). The other left atrial volumes were not altered after PMV. The early increase in conduit volume and the decrease in left atrial presystolic volume indicate that PMV has favorable effects on atrial reservoir and conduit functions. PMV therefore improves atrial mechanic functions.

Adult↗