Left Atrial Appendage-Flow Velocity Predicts Cardioversion Success in Atrial Fibrillation

The Long-Term Results of Three Catheter Ablation Methods in Patients With Paroxysmal Atrial Fibrillation: A 4-Year Follow-Up Study

Aims: Catheter ablation of paroxysmal atrial fibrillation (PAF) has been shown to be effective and safe. However, recurrence of PAF varies between 10 and 30% for radiofrequency ablation. There have been no reports comparing long-term recurrence rates following radiofrequency ablation, cryoablation, and three-dimensional guided cryoablation plus radiofrequency ablation. The aim of this study was to observe the long-term recurrence rate of PAF when treated by these three catheter ablation methods, and to explore clinical factors that can potentially predict PAF recurrence following catheter ablation. Methods: There were 238 patients involved in this study, including 106 radiofrequency (RF) ablation cases (RF group), 66 cryoablation cases (Freeze group), and 66 cases treated by three-dimensional guided cryoablation combined with radiofrequency ablation (Freeze-plus-RF group). All patients underwent standardized follow-up. The recurrence rate of atrial fibrillation (AF) in the three groups was calculated. Predictive factors for the recurrence of AF were also investigated. Results: At 48 months (the median follow-up period), the sinus rhythm maintenance rate was 77.4% in the RF group, 72.7% in the Freeze group, and 81.8% in the Freeze-plus-RF group. The maintenance rate of sinus rhythm was highest in the Freeze-plus-RF group, but differences among the three groups were not statistically significant. Further analysis found that the preoperative left atrial appendage emptying velocity (LAAEV) (recurrence vs. no recurrence, 56.58 ± 18.37 vs. 65.59 ± 18.83, respectively, p = 0.003), left atrial (LA) anteroposterior dimension (recurrence vs. no recurrence, 36.56 ± 4.65 vs. 35.00 ± 4.37, respectively; p = 0.028), and LA vertical dimension (recurrence vs. no recurrence, 56.31 ± 6.96 vs. 53.72 ± 6.52, respectively; p = 0.035) were related to postoperative recurrence. Multiple Cox regression analysis showed that only LAAEV was predictive of postoperative recurrence of PAF (hazard ratio: 0.979; 95% confidence interval: 0.961-0.997). Conclusion: Our study found that there was no statistically significant difference in long-term recurrence rates among the RF, Freeze, and Freeze-plus-RF groups. Preoperative LAAEV is an independent predictor of postoperative recurrence of PAF.

Morphologic and functional features of left atrial appendage in Iranian population: an echocardiographic study

Introduction: Cardioembolic events are accompanied by left atrial appendage (LAA) in patients suffering from atrial fibrillation (AF); therefore, the LAA closure is implemented as a preventive strategy. The detection of LAA morphologies and function is a paramount step before establishing the LAA closure. Herein, we sought to determine the morphologic features of the LAA in an Iranian population using echocardiographic evaluation.

Methods: Seventy-two near-normal heart patients were investigated by conducting a cross-sectional study. All patients were examined using the 2-dimensional and 3-dimensional transesophageal echocardiography (2D- and 3D-TEE) method. The anatomical features and functions of LAA were examined. All images were stored and analyzed offline.

Results: The patients’ mean age was 39 ± 15.5 year and 33 (45.8%) were female. The most frequent shape of LAA was wind sock . More LAA lobes was observed in patients with AF compared to those with NSR. In comparison with AF group, the NSR had higher LAA flow velocity (P < 0.01). The paroxysmal AF had greater LAA flow velocity and LAA ejection fraction in comparison with the chronic AF (39 ± 19 vs. 75 ± 22, P < 0.01; and 49±4 vs. 72±14, P < 0.003; respectively). The paroxysmal AF had smaller systolic LAA orifice area in comparison with the chronic AF (P < 0.02).

Conclusion: The morphologic features of LAA in Iranian population were within the range of other studies and LAA length and orifice diameters in 2D- and 3D-TEE were consistent. In addition, AF influenced the morphologies and functions of LAA compared to sinus rhythm.

Assessment of Left Atrial Appendage Morphology and Function in Patients with Non-valvular Paroxysmal Atrial Fibrillation with Different Rhythms Using Real-Time 3D Transesophageal Echocardiography

The aim of this study was to evaluate the morphology and function of the left atrial appendage (LAA) in different rhythms of paroxysmal atrial fibrillation (PaAF) patients using real-time 3D transesophageal echocardiography. This study included 46 patients with PaAF-24 with PaAF with sinus rhythm (PaAF-S) and 22 with PaAF with fibrillation (PaAF-F)-and 23 healthy volunteers. Real-time 3D transesophageal echocardiography images of the LAA were acquired in all patients. LAA end-diastolic volume increased in PaAF-S and PaAF-F, whereas LAA end-systolic volume increased only in PaAF-F. LAA emptying index, end-diastolic volume and end-systolic volume were strongly negatively correlated. LAA emptying index was positively correlated with percentage changes in LAA area and diameter, as well as flow velocity. The co-occurrence of spontaneous echo contrast and thrombus gradually increased in the PaAF-F group, compared with the PaAF-S group. The morphology and change in function of the LAA in patients with paroxysmal PaAF can be evaluated with superior feasibility and reproducibility using real-time 3D transesophageal echocardiography. Morphologic changes in the LAA appeared earlier than changes in LAA function during the course of PaAF. Spontaneous echo contrast and thrombus co-occurred more often in PaAF-F than in PaAF-S.

Left atrial stiffness and its implications for cardiac function

Proper atrial function is essential for overall cardiovascular performance, mainly by its four major functions, namely, bioelectrical, hormonal, metabolic and hemodynamic. With regard to the latter, atria modulate ventricular filling by smoothing the transformation of the continuous venous return to the intermittent filling pattern of the ventricles during diastole through three main components: a phase of reservoir mainly during ventricular systole, a conduit phase during ventricular diastole and an active phase in late ventricular diastole. Although the atria assume a dynamic role in ventricular filling progression, atrial function and emptying pattern is, conversely, highly influenced by the ventricular diastolic wall stress, underlying the close connection observed between these chambers. This review focuses essentially on left atrial mechanical role, particularly on the physiological and clinical consequences of disturbed atrial compliance.

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.