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Abnormalities of left atrial function after cardioversion: an atrial strain rate study.

BACKGROUND AND OBJECTIVES: The role of atrial myocardial dysfunction after cardioversion is unclear. In a comparison of patients after successful cardioversion from chronic atrial fibrillation (CAF) and normal controls, we sought to determine whether Doppler-derived atrial strain rate (A-sr) could be used to measure global left atrial function and whether A-sr was reduced in patients with CAF. METHODS: A-sr was measured from the basal septal, lateral, inferior and anterior atrial walls from the apical four-chamber and two-chamber views in 37 patients with CAF who had been cardioverted to sinus rhythm and followed up for 6 months, and in a cohort of 37 healthy people. Conventional measures of atrial function included peak transmitral A-wave velocity, A-wave velocity time integral, atrial fraction and the left atrial ejection fraction. Doppler tissue imaging was used to estimate atrial contraction velocity (A' velocity). In addition to amplitude parameters, the time to peak A-sr was measured from aortic valve closure. RESULTS: Immediately after cardioversion, A-sr in the CAF cohort (baseline) was significantly lower than in controls (mean (SD) -0.53 (0.31) v -1.6 (0.75) s(-1); p<0.001); the A-sr correlated with A' velocity (r = 0.63; p<0.001) in patients. Atrial function improved over time, with maximal change observed in the initial 4 weeks after cardioversion. The time to peak A-sr was increased in the CAF group compared with controls (0.55 (0.15) v 0.46 (0.12) s), but this failed to normalise over time. CONCLUSION: A-sr is a descriptor of atrial function, which is reduced after cardioversion from CAF and subsequently recovers.

Aged↗

Plasma von Willebrand factor, fibrinogen and soluble P-selectin levels in paroxysmal, persistent and permanent atrial fibrillation. Effects of cardioversion and return of left atrial function.

BACKGROUND: Atrial fibrillation is associated with increased risk of stroke and thromboembolism, possibly by conferring a prothrombotic or hypercoagulable state. However, it is unclear whether or not this differs in the clinical subgroups of chronic atrial fibrillation patients, that is, in those with paroxysmal, persistent or permanent atrial fibrillation. We therefore hypothesized that: (i) there are differences in the prothrombotic state between these patients; and (ii) reduction in indices of hypercoagulability would follow elective electrical cardioversion of persistent atrial fibrillation and the return of left atrial function. PATIENTS AND METHODS: We studied 69 patients with chronic atrial fibrillation: 23 with paroxysmal atrial fibrillation (16 males; mean age 65 years+/-SD 13); 23 with persistent atrial fibrillation (16 males; 65 years+/-13), with a mean duration of atrial fibrillation of 3 months (range 2 to 6 months); and 23 with permanent atrial fibrillation (16 males; 67 years+/-10). Blood results were compared to 20 age- and sex-matched healthy controls. The patients with persistent atrial fibrillation then underwent elective DC cardioversion, with Doppler echocardiographic examinations and bloods tests performed prior to cardioversion, and at 3 and 12 weeks afterwards. The prothrombotic state was quantified by measurement of plasma levels of fibrinogen, soluble P-selectin (an index of platelet activation) and von Willebrand factor (a marker of endothelial dysfunction). RESULTS: Permanent atrial fibrillation was associated with significantly raised levels of von Willebrand factor, soluble P-selectin and fibrinogen (all P<0.001); paroxysmal atrial fibrillation with significantly elevated levels of plasma von Willebrand factor (P=0.0067) and fibrinogen (P=0.0001) but not soluble P-selectin (P=0.472); and persistent atrial fibrillation with normal levels of fibrinogen, von Willebrand factor and soluble P-selectin when compared to healthy controls (all P=ns). Stepwise multiple regression analyses demonstrated that the presence of atrial fibrillation was an independent predictor of abnormal von Willebrand factor, fibrinogen and soluble P-selectin levels. Electrical cardioversion of the patients with persistent atrial fibrillation did not significantly alter levels of von Willebrand factor (P=0.766), soluble P-selectin (P=0.726) or fibrinogen (P=0.50) despite maintenance of sinus rhythm and a significant return of left atrial systolic function (as quantified by the presence of A wave on Doppler echocardiography) at 3 months. CONCLUSION: There were significant differences in the prothrombotic state when patients with paroxysmal and permanent atrial fibrillation are compared to matched patients with persistent atrial fibrillation or controls in sinus rhythm. Cardioversion of persistent atrial fibrillation did not significantly alter indices of hypercoagulability even after 3 months maintenance of sinus rhythm, despite the return of atrial systole.

Adult↗

Influence of left atrial function on Doppler transmitral and pulmonary venous flow patterns in dilated and hypertrophic cardiomyopathy: evaluation of left atrial appendage function by transesophageal echocardiography.

Information regarding the relation of left atrial (LA) function to transmitral and pulmonary venous (PV) flow is limited. Using transesophageal echocardiography, we analyzed this relation in 23 patients with dilated cardiomyopathy (DCM) and 25 patients with hypertrophic cardiomyopathy (HCM). Left atrial appendage (LAA) function was assessed as a substitute for overall LA function. Transmitral and PV flow-velocity variables, the LAA emptying flow velocity (LAA-A), and the LAA ejection fraction (LAA-EF) were determined. Each patient group was divided into two subgroups with a normal ( < 15 mm Hg) or elevated ( > or = 15 mm Hg) mean pulmonary wedge pressure (PWP). Transmitral and PV flow patterns as well as LA function were similar in the two subgroups with a normal PWP (11 patients with DCM and 14 patients with HCM). For the subgroups with an elevated PWP, however, the peak velocity ratio of the early filling wave (E) to atrial contraction wave (A) was higher in DCM patients (n = 12) than in HCM patients (n = 11) (2.1 +/- 0.7 vs 1.3 +/- 0.2; p < 0.01). This difference mostly resulted from a lower A velocity in the DCM group than in the HCM group (30 +/- 10 cm/sec vs 43 +/- 7 cm/sec; p < 0.05). In addition, the reverse flow velocity at atrial contraction in the PV was lower in the DCM group than in the HCM group (19 +/- 8 cm/sec vs 37 +/- 8 cm/sec; p < 0.01). These findings were associated with poorer LA systolic function in the DCM group (LAA-A, 35 +/- 13 cm/sec vs 60 +/- 11 cm/sec; LAA-EF, 37% +/- 12% vs 55% +/- 15%, p < 0.05, respectively). Our data suggest that a restrictive transmitral flow pattern develops more easily in DCM than in HCM because LA dysfunction is present in DCM, and that LA contractility plays an important role in determining the atrial contraction wave of transmitral and PV flows with elevated LA pressure.

Atrial Function, Left↗

Left atrial function after Cox's maze operation concomitant with mitral valve operation.

BACKGROUND: This study examined whether the atrial fibrillation that commonly occurs in patients with a mitral valve operation could be eliminated by a concomitant maze operation. METHODS: Left atrial function after Cox's maze operation performed concomitantly with a mitral valve operation was evaluated in 10 patients ranging in age from 38 to 67 years (mean age, 54 years). Seven patients who had had coronary artery bypass grafting served as the control group. Using transthoracic echocardiography, the ratio between the peak speed of the early filling wave and that of the atrial contraction wave (A/E ratio) and the atrial filling fraction (AFF) were determined from transmitral flow measurements. These two indices have been considered to represent the contribution of left atrial active contraction to ventricular filling. RESULTS: The A/E ratio and the AFF were significantly lower in the maze group (0.35 +/- 0.17 versus 0.97 +/- 0.28 [p < 0.01] and 17.6% +/- 8.8% versus 36.8% +/- 6.4% [p < 0.01], respectively). The A/E ratio and the AFF correlated inversely with age (r = -0.72, p < 0.05 and r = 0.76, p < 0.05, respectively) in the maze group. In an angiographic study, the mean left atrial maximal volume index in the maze group was approximately three times larger than that in the control group (117.5 +/- 24.3 mL/m2 versus 35.3 +/- 6.6 mL/m2 [p < 0.01]). The left atrial active emptying volume index was significantly smaller in patients in the maze group (7.2 +/- 2.5 mL/m2 versus 13.1 +/- 4.6 mL/m2 [p < 0.01]). CONCLUSIONS: After the maze procedure performed concomitantly with a mitral valve operation in patients with a dilated left atrium, left atrial contraction is detectable but incomplete in the elderly.

Adult↗

The relative importance of left atrial function versus dimension in predicting atrial fibrillation after coronary artery bypass graft surgery.

BACKGROUND: Atrial fibrillation (AF) is a common complication after coronary artery bypass graft (CABG) surgery. The purpose of this study was to determine whether pre-existing left atrial dysfunction is a predictor of postoperative AF compared with other clinical predictors. METHODS: Ninety-three patients undergoing CABG were prospectively studied. Intraoperatively, transesophageal echocardiography was performed to measure left atrial size, transmitral flow velocity, and other routine parameters. Left atrial function was estimated by the following formula: Atrial index = Transmitral VTI total x LAEF/Left atrial maximal area (where VTI = velocity time integral of E and A waves, LAEF = left atrial ejection fraction). The association of potential clinical predictors with the occurrence of postoperative AF was evaluated by chi2 or Fisher exact tests, followed by stepwise multivariate logistic regression model. P values and odds ratios (OR) with 95% CIs were reported. Significance was set at P <.05. RESULTS: Postoperative AF occurred in 28 of 93 patients (30.1%). Patients with postoperative AF were older (67.0 +/- 8.3 vs 61.5 +/- 9.6 years, P =.0075), had larger left atrial maximal area (14.3 +/- 4.6 cm(2) vs 10.9 +/- 4.3 cm2, P <.001), lower atrial index (0.54 +/- 0.56 vs 0.82 +/- 0.64, P =.008), larger body surface area (BSA) (OR 57, 95% CI 3.97-827), longer aortic cross-clamp time (OR 1.03, 95% CI 1.00-1.05), and more likely to have a postoperative myocardial infarction (OR 3.28, 95% CI 0.99-10.87) compared with those without AF. By multivariate analysis, only age (OR 1.11, 95% CI 1.04-1.19, P =.002) and atrial dimension (OR 1.75, 95% CI 1.03-2.96, P =.038) were significant independent predictors of postoperative AF. Body surface area also increased the odds of postoperative AF, but the CI was wide (OR 114, 95% CI 4.65-2810, P =.004). CONCLUSIONS: Our results demonstrate that age and atrial enlargement, rather than atrial function, were independent predictors of postoperative AF.

Adult↗

Left atrial function in patients with a high C-reactive protein level and paroxysmal atrial fibrillation.

OBJECTIVE: We evaluated left atrial dimensions and function in high C-reactive protein (CRP) patients with paroxysmal atrial fibrillation. BACKGROUND: In patients with increased plasma levels of CRP left atrial dysfunction may enhance the occurrence of arrhythmias. METHODS: Two-dimensional and pulsed Doppler echocardiography, were performed in 20 consecutive patients with high CRP levels and paroxysmal atrial fibrillation (group CRf) and in 20 patients with high CRP levels without this arrhythmia (group CR). Twenty normal subjects (group N) were also investigated. Groups were matched for age and gender. RESULTS: CRP was increased in the CRf (median = 1.03 mg/dl), CR (median = 0.84 mg/dl) and N groups (median = 0.23 mg/dl), (p < 0.001) for all comparisons. The CRf, CR and N groups had similar systolic and diastolic blood pressure, left ventricular mass index, left ventricular ejection fraction, isovolumic relaxation time and peak early and late transmitral Doppler flow velocities. Maximal left atrial volume was greater only in the CRf group (54.4 +/- 6.3 ml) compared with the N group (50.3 +/- 4.9 ml, p < 0.05). Left atrial volume preceding atrial contraction was similar in all groups, p=NS. Left atrial minimal volume decreased from 23.0 +/- 1.8 ml in the CRf group, to 19.8 +/- 1.8 ml in the CR group, p < 0.001 and to 18.1 +/- 2.1 ml in the N group, (p < 0.02). The passive emptying fraction of the CRf and CR groups was comparable to that of normal subjects. The CRf group had a decreased left atrial active emptying fraction (0.25 +/- 0.08) compared with the CR (0.36 +/- 0.09) and N groups (0.39 +/- 0.08), p < 0.001 for both comparisons. The reservoir fraction was decreased only in the CRf group compared to normal subjects (1.37 +/- 0.25 vs. 1.82 +/- 0.43, p < 0.001). CONCLUSIONS: These results suggest that the occurrence of paroxysmal atrial fibrillation in patients with a high CRP level is associated with enlargement of the left atrium, depression of its contractile function and is independent of left ventricular hypertrophy and function. The mechanisms linking these variables remain undefined.

Aged↗

Impaired left atrial function after heart transplantation: disparate contribution of donor and recipient atrial components studied on-line with quantitative echocardiography.

BACKGROUND: Because of a lack of noninvasive techniques, left atrial function after orthotopic heart transplantation has not been well characterized. METHODS: Global left atrial performance and the relative contributions of donor and recipient atrial components were assessed with transthoracic echocardiography with on-line automated border detection in 20 patients with normal left ventricular systolic function 1 to 6 years (mean 3.5 +/- 0.3 years [standard error]) after heart transplantation. RESULTS: The mean left atrial area at ventricular end-systole was 22.9 +/- 1.5 cm2, the mean left atrial emptying fraction ([left atrial area at ventricular end-systole--left atrial area at ventricular end-diastole]/left atrial area at ventricular end-systole) was 29.7% +/- 2.6%, and the fractional area change caused by active contraction was 27.8% +/- 3.1%. Compared with controls, patients had larger atria, depressed emptying, and reduced fractional active contraction. Although the recipient to donor area ratio was 3:2, the proportion of atrial emptying (change in area from mid-to-late ventricular diastole divided by the total left atrial change during ventricular diastole) contributed by the recipient component was greatly diminished when compared with that of the donor component (1.4% +/- 3.5% versus 31% +/- 2.7%) (p = 0.0001). CONCLUSIONS: Despite being anatomically smaller, the functional contractile contribution of the donor component dominated atrial emptying. Thus, after heart transplantation, global left atrial function is depressed, predominantly because of dysfunction of the recipient atrial component.

Adult↗

Impairment of left atrial function predicts post-operative atrial fibrillation after coronary artery bypass graft surgery.

AIMS: Despite the prevalence of atrial fibrillation (AF) occurring after cardiac surgery, its pathophysiology is incompletely understood. Specifically, whether left atrial (LA) structural remodelling occurs, contributing to a decrement in atrial function and AF has not been previously determined. This study sought to determine the relationship between LA function and post-operative AF. METHODS AND RESULTS: Three hundred patients undergoing elective coronary artery bypass graft surgery were monitored with intraoperative transoesophageal echocardiography to determine LA function and dimensions. Post-operative AF was monitored with continuous telemetry until hospital discharge. The relationship between clinical factors versus LA function and dimension was assessed using multi-variate logistic regression. By univariate analysis, patients who subsequently developed post-operative AF had a larger LA area and LA appendage area, and lower LA ejection fraction measured in the pre-bypass period compared to those without subsequent AF. By multivariable analysis, in addition to clinical data including age (odds ratio [OR] 1.11, 95% confidence interval [CI] 1.05-1.16, P<0.0001), body surface area (OR 13.31, 95% CI 1.87-94.5, P=0.0097) and white race, post-bypass atrial systolic function (atrial filling fraction 0.36, OR 2.51, 95% CI 1.03-6.13, P=0.04) and abnormal relaxation of the left ventricle (E duration 270 ms) (OR 2.89, 95% CI 1.34-6.24, P=0.0067) independently increased the risk of post-operative AF. CONCLUSION: These results demonstrate that some of the structural and functional changes in the atria common to chronic AF in the elderly population are also prevalent in surgical patients who develop post-operative AF, suggesting that post-operative and chronic AF may have similar pathophysiology.

Atrial Fibrillation↗

Left ventricular Doppler filling pattern in dilated cardiomyopathy: relation to hemodynamics and left atrial function.

This study attempted to examine the relation of left ventricular filling patterns to hemodynamic status and left atrial function in dilated cardiomyopathy. Transesophageal echocardiography and cardiac catheterization were performed in 41 patients with dilated cardiomyopathy (six with an ischemic origin). Transmitral, left atrial appendage, and pulmonary venous flow velocities were recorded with the pulsed Doppler method. Left atrial systolic function was assessed by the peak velocity of the left atrial appendage emptying wave and pulmonary venous flow reversal during atrial systole. Patients were classified into three groups according to their left ventricular filling patterns. Group 1 showed an abnormal relaxation pattern (E wave/A wave ratio <1, n = 17), group 2 had a normal or pseudonormal pattern (1 < or = E/A < 2, n = 11), and group 3 had a restrictive pattern (E/A > or = 2, n = 13). No differences were found among the groups with regard to age, gender, heart rate, and M-mode echocardiographic indices of left ventricular function. Compared with patients in group 1, those in groups 2 and 3 had more symptoms (New York Heart Association functional class III or IV) and had higher left ventricular filling pressures. The sensitivity of an E/A ratio > or = 1 for predicting a pulmonary capillary wedge pressure > or = 15 mm Hg was 75% and the specificity was 94%. Despite a similar increase of filling pressures, group 3 patients had a lower left atrial appendage emptying velocity, pulmonary venous flow reversal velocity, and mitral A velocity than did group 2 patients. The sensitivity and specificity of an E/A ratio > or = 22 for detecting left atrial dysfunction (left atrial appendage emptying velocity < or = 40 cm/sec) was 85% and 86%, respectively. In conclusion, among patients with dilated cardiomyopathy, those who had a restrictive or pseudonormal filling pattern were in a higher functional class and had higher filling pressures. Further studies are needed to determine the therapeutic and prognostic significance of left atrial dysfunction, which was common in patients with a restrictive pattern.

Adult↗

Extensive ablation during pulmonary vein antrum isolation has no adverse impact on left atrial function: an echocardiography and cine computed tomography analysis.

BACKGROUND: Although pulmonary vein antrum isolation (PVAI) may cure atrial fibrillation (AF) and improve left atrial (LA) function, the effect of extensive LA ablation on LA function is not well known. OBJECTIVE: To assess the impact of PVAI on LA function remotely postablation. METHODS: Consecutive patients undergoing PVAI had either transthoracic (TTE) and transesophageal (TEE) echocardiography (n = 41) or cine EBCT (n = 26) performed preablation and 6 months postablation. Only patients with paroxysmal and persistent, but not permanent, AF were included. Imaging was done in sinus rhythm for all patients. LA diameter (LAD), LA systolic and diastolic areas, and left atrial fractional area change (LFAC) were assessed by TTE. Transmitral (TMF), left atrial appendage (LAA), and pulmonary venous (PVF) Doppler flows were measured by TEE. Peak A on TMF, LAA peak emptying velocity (LAAF), and peak A reversal (AR) on PVF were used as surrogates of LA contractile function. Peak S on PV flow was used as a surrogate of reservoir function. LA areas, volumes, and LA ejection fraction (LAEF) were measured from cine EBCT. RESULTS: Mean radiofrequency ablation time was 45 +/- 21 minutes. All four PVs were isolated for all patients; there were no cases of PV stenosis. Echocardiography revealed a significant reduction in LAD and LA areas post-PVAI. Both peak A and peak AR were also higher post, while other variables showed strong trends toward improvement. In the subset of patients with persistent AF, post-PVAI improvements were seen in LA size, peak A, and even peak S (P = 0.04). Cine EBCT showed a significant decrease in both LA areas and volumes post-PVAI. There was also a significant improvement in LAEF post-PVAI from 17 +/- 6% to 22 +/- 5% (P = 0.01). CONCLUSION: Extensive ablation during PVAI does not cause deterioration in LA function, and may cause long-term improvement, especially in patients with higher AF burden.

Atrial Fibrillation↗

Left atrial functions after myocardial infarction.

Acute myocardial infarction results in not only left ventricular but also left atrial dysfunction. Left atrial function is important for optimal filling of the left ventricle. In this study, we aimed at evaluating left atrial functions 6 months after acute myocardial infarction in three different patient groups (thrombolytic therapy, primary percutaneous intervention, or no reperfusion strategies). Between October 2002 and May 2003, 48 patients with ST elevation myocardial infarction who were either administered thrombolytic therapy (group T, n=16), underwent primary angioplasty (group A, n=20), or underwent no reperfusion therapy (group C, n=12) at our unit were enrolled into the study. Echocardiography was performed in these patients 6 months after acute myocardial infarction. Left atrial contractility was assessed by atrial ejection force. Left atrial contribution was assessed by atrial fractional shortening and left atrial volume was calculated. The left atrial volume was significantly higher in group C (P<0.05), but there was no significant difference between groups A and T (P>0.05). Patients in group C had significantly lower atrial ejection force values compared with the other groups (P<0.05). Atrial fractional shortening was not significantly different among the three groups (P>0.05). Atrial ejection force, which is an indicator of left atrial contractility, is better with either angioplasty or thrombolysis. Left atrial volume is higher in patients who were not treated with reperfusion strategies. Further studies are needed to explain the mechanism involved.

Aged↗

Usefulness of intracardiac Doppler assessment of left atrial function immediately post-pulmonary vein antrum isolation to predict short-term recurrence of atrial fibrillation.

Doppler assessments of pulmonary venous (PV) and left atrial appendage flows are useful surrogates of left atrial (LA) function, but it is unknown if these can predict atrial fibrillation (AF) recurrence after pulmonary vein antrum isolation. We compared Doppler surrogates of LA function immediately after pulmonary vein antrum isolation in patients with AF recurrence versus matched patients without recurrence. Patients with a 6-month recurrence had significantly lower LA appendage peak emptying velocity (19 +/- 10 vs 29 +/- 11 cm/s) and lower peak PV systolic wave velocity (36 +/- 17 vs 46 +/- 22 cm/s) compared with those without, suggesting that intracardiac Doppler assessment of LA function after AF ablation predicts AF recurrence.

Aged↗

Assessment of left atrial function in patients with hypertensive heart disease.

Left atrial function in patients with hypertensive heart disease was compared with that in control subjects. In patients with hypertensive heart disease, the time constant of left ventricular relaxation was significantly greater than that in controls (54 +/- 18 vs 31 +/- 16 msec; p less than 0.01). The ratio of left ventricular filling volume before atrial contraction (left atrial reservoir volume/left atrial emptying volume before atrial contraction, and conduit volume/flow volume from the pulmonary vein into the left ventricle) to left ventricular stroke volume was significantly smaller than that in controls (65 +/- 13 vs 76 +/- 7%; p less than 0.05). In patients with hypertensive heart disease, the ratio of reservoir volume to stroke volume was not significantly different from that in controls, while the ratio of conduit volume to stroke volume was significantly smaller than that in controls (43 +/- 13 vs 57 +/- 9%; p less than 0.05). The latter ratio was inversely correlated with the time constant of left ventricular relaxation (r = -0.05, p less than 0.05). In patients with hypertensive heart disease, the ratio of left ventricular filling volume during atrial contraction to stroke volume was significantly larger than that in controls (35 +/- 13 vs 24 +/- 7%; p less than 0.05). The ratio of left ventricular filling volume during atrial contraction to stroke volume had a significant inverse correlation with the ratio of conduit volume to stroke volume (r = -0.84, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Normal left atrial function determined by 2-dimensional echocardiography.

To obtain normal values for left atrial function noninvasively, volumes of the left atrium and ventricle were calculated in 52 volunteers by 2-dimensional echocardiography. A light pen digitizing and computation system, controlled by a microprocessor, was used to outline the left atrium and ventricle in orthogonal apical views. Then, to calculate end-systolic and end-diastolic atrial and ventricular volumes, a modified Simpson's rule formula was used. End-systolic left atrial volume (mean +/- standard deviation) was 37 +/- 11.7 ml or 21 +/- 6.6 ml/m2. The change in left atrial volume from end-systole to end-diastole was 24 +/- 7.6 ml or 13.5 +/- 4.3 ml/m2, which represented 37 +/- 12.9% of left ventricular stroke volume. The mean fractional emptying of the left atrium was 65 +/- 8.9% and the conduit volume was 41 +/- 14.0 ml or 23 +/- 7.9 ml/m2. These values are similar to those reported in studies in which left atrial function was calculated from contrast angiography.

Adult↗

Left atrial function and ventricular filling in hypertensive patients with paroxysmal atrial fibrillation.

OBJECTIVES: We evaluated left atrial dimensions and function, as well as left ventricular structure and filling, in hypertensive patients with paroxysmal atrial fibrillation. BACKGROUND: In hypertensive patients, left atrial dilation and enhanced volume transport may facilitate arrhythmias. METHODS: Left ventricular two-dimensional and M-mode echocardiograms and pulsed Doppler echocardiography of transmitral flow were performed in 17 consecutive primary hypertensive patients with paroxysmal atrial fibrillation (group EHf) and in 34 patients with high blood pressure without this arrhythmia (group EH). Seventeen normal subjects (group N) were also investigated. Groups were matched for age and gender. RESULTS: The EH and EHf groups had similar systolic arterial pressures ([mean +/- SD] group EH 185 +/- 27, group EHf 173 +/- 25 mm Hg, p = NS) and left ventricular mass index (group EH 154 +/- 55, group EHf 131 +/- 57.8 g/m2, p = NS), and their M-mode left ventricular systolic wall stress and fractional shortening were comparable to those of normal subjects. M-mode left atrial maximal (group N 37.8 +/- 6, group EH 37.9 +/- 4.6, group EHf 44.6 +/- 6.7 mm, p < 0.05 for group EHf vs. groups N and EH) and minimal diameters and the diameter preceding atrial contraction (group N 31 +/- 3.6, group EH 34.5 +/- 5, group EHf 40.4 +/- 6.9 mm, p < 0.001 for group EHf vs. group N; p < 0.05 for group EHf vs. group EH) were greater in group EHf than in group EH and group N subjects, whereas only the latter diameter was increased in group EH (p < 0.05 vs. group N), so that left atrial fractional shortening was higher than normal only in group EH (group N 10.8 +/- 4.4%, group EH 14.6 +/- 5.5%, group EHf 9.3 +/- 5.3%; group EH vs. group N, p < 0.05; group EHf vs. group EH, p < 0.05). The pulsed Doppler ratio of early to late transmitral flow rates (E and A wave velocity/time integrals x mitral annulus area) was lower than normal in group EH (group N 2.9 +/- 2.2, group EH 1.75 +/- 0.8, group EHf 2.8 +/- 0.8; group EH vs. group N, p < 0.05; group EHf vs. group EH, p < 0.001; group EHf vs. group N, p = NS) and was "normalized" in group EHf, early flow being increased in this group (group N 42 +/- 13, group EH 39 +/- 29, group EHf 60 +/- 17 ml; group EHf vs. group N, p < 0.05; group EHf vs. group EH, p < 0.05). CONCLUSIONS: These results suggest that the occurrence of paroxysmal atrial fibrillation in hypertension is associated with enlargement of the left atrium, depression of its contractile function and "normalization" of the pattern of left ventricular filling and is independent of left ventricular hypertrophy and systolic wall stress. The mechanisms linking these variables remain undefined.

Aged↗

Left atrial systolic function assessed by left atrial ejection force in patients with sick sinus syndrome and paroxysmal atrial fibrillation.

We evaluated left atrial systolic function using left atrial ejection force (LAEF) in 19 patients with sick sinus syndrome (SSS) and in 20 with paroxysmal atrial fibrillation (Paf) whose ages ranged from 48 to 80 years. We also evaluated 35 normal individuals for comparison. The LAEF was calculated as 1/3 x mitral valve area x (peak velocity of A wave)2 using two-dimensional and pulsed-Doppler echocardiography according to Newton's law of motion and hydrodynamics. In normal individuals, LAEF positively correlated with age (r = 0.82, p < 0.01). Normal LAEF was calculated as 0.098 x age - 0.74 (kdynes) from the regression line. Because of this correlation, we used age-corrected LAEF (%LAEF) that was calculated as (measured LAEF / normal LAEF) x 100. The results showed that this value was 53+/-26% in patients with SSS and 54+/-26% in patients with Paf. Both were significantly lower than normal individuals (p < 0.001). Among SSS subtypes, %LAEF was lower in types II and III than in type I (51+/-14%, 37+/-19%, and 81+/-35%, respectively). In conclusion, left atrial systolic function is depressed in patients with Paf and SSS, in particular, types II and III. These results suggest that the pathological abnormalities extend not only to the sinus node but also to the left atrial muscle in patients with SSS and Paf.

Aged↗

Left atrial functional reserve in patients with nonischemic dilated cardiomyopathy: an echocardiographic dobutamine study.

OBJECTIVE: To evaluate left atrial functional reserve in patients with chronic heart failure and nonischemic dilated cardiomyopathy (DCM). BACKGROUND: Left ventricular functional status has been investigated using echocardiographic dobutamine. METHODS: In 35 consecutive patients (29 men and 6 women; mean +/- SD age, 42.37 +/- 13.5 years), peak oxygen consumption (O(2)max) was measured; the day after, a low-dose dobutamine (5 to 10 micro g/kg/min, of 5 min each step) study was performed. Left atrial volumes at mitral valve opening, onset of left atrial systole, and mitral valve closure were measured by using two-dimensional echocardiography. Left atrial active emptying volume (LAEV) [volume at onset of atrial systole - minimal volume] was calculated, as was left atrial active emptying fraction (LAEF): [(volume at onset of atrial systole - minimal volume)/volume at onset of atrial systole] x 100. The changes (values obtained after inotropic stimulation minus those obtained at baseline) of the above-mentioned echocardiographic variables were considered as left atrial functional reserve. RESULTS: In the entire study group after dobutamine infusion, increases in LAEV (3.34 +/- 7.54 mL, p = 0.01) and LAEF (6 +/- 13.2%, p = 0.01) were observed. The changes in the above-mentioned parameters were correlated with O(2)max values (r = 0.73 and r = 0.71, respectively; p < 0.001). After inotropic stimulation, LAEV and LAEF were increased in patients with O(2)max values > 14 mL/kg/min (5.62 +/- 7.28 mL and 10.04 +/- 13.13%, respectively) and decreased in patients with O(2)max values < 14 mL/kg/min (- 1.08 +/- 6.13 mL and - 1.6 +/- 9.9%, respectively; p = 0.01 for both). CONCLUSION: Echocardiographic dobutamine can evaluate left atrial functional reserve in patients with nonischemic DCM.

Adult↗