The Left Atrial Appendage, a Small, Blind-Ended Structure

Predictors of left atrial appendage emptying velocity: Derivation and validation of CHIRP3(M-1) score

BACKGROUND

Atrial fibrillation (AF) leads to impaired left atrial appendage contractility, increasing the risk of thromboembolic stroke. The left atrial appendage emptying velocity (LAAev) measured on transesophageal echocardiogram (TEE) is a marker of increased thromboembolic risk.

OBJECTIVES

The purpose of this study was to evaluate predictors of reduced LAAev for identifying individuals at increased risk for cardiogenic stroke.

METHODS

This was a single-center retrospective review of TEEs and clinical charts. Predictors of LAAev <30 cm/s were identified using logistic regression. A risk prediction model was created using stepwise selection in a derivation set (n = 695) and separately tested in a validated set (n = 300).

RESULTS

We included TEEs on 995 patients (age 71.3±12.7 years; female 38.1%; history of AF 82.1%; in AF at evaluation 27.7%; CHA2DS2-VASc score 4.1 ± 1.9; LAAev 41.6 ± 21.0 cm/s). Significant multivariable predictors of LAAev <30 cm/s in derivation set were used to create the CHIRP3M-1 score containing 8 variables: Coronary artery disease (1), congestive Heart failure (1), Increased left atrial volume index ≥42 mL/m2 (1), current Rhythm AF (1), Paroxysmal AF (2), Persistent AF (3), longstanding Persistent/permanent AF (4), and greater than moderate Mitral regurgitation (-1). In the validation set, as compared to intermediate scores (3-4), those with low scores (≤2) and high scores (≥5) had odds ratios for LAAev <30 cm/s of 0.41 (0.21, 0.78, P = .007) and 2.58 (95% confidence interval 1.45-4.61, P = .001), respectively.

CONCLUSION

We developed and validated a novel risk stratification system to predict reduced LAAev using clinical and echocardiographic variables. This may help refine the stratification of cardiogenic stroke risk.

Echocardiographic assessment of left atrial appendage morphology and function-an expert proposal by the German Working Group of Cardiovascular Ultrasound

The left atrial appendage is a blind ending cardiac structure prone to blood stasis due to its morphology. This structure is a preferred region of thrombogenesis in relation to reduced myocardial contractility of the atrial wall. Blood stasis occurs primarily in low flow conditions. One of the tasks of echocardiography is the analysis of morphology and function of the left atrial appendage. The detection of thrombi by echocardiography is difficult and must be carried out thoroughly and carefully to avoid potential complications-especially in the context of rhythm control. The assessment of thromboembolic risk, especially in patients with unknown and presumed atrial fibrillation is a second challenge by characterizing atrial function and flow conditions in the left atrial appendage. Thus, this proposal focuses on the obvious problems of echocardiography when assessing left atrial appendage and the role of this method in planning a potential interventional closure of left atrial appendage.

Morphological and functional assessment of the left atrial appendage in daily practice: a comprehensive approach using basic and advanced echocardiography with practical tips

Cardioembolic stroke is the most serious and life-threatening complication of atrial fibrillation (AF), with an associated mortality up to 30% at 12 months. Approximately 47% of thrombi in valvular AF and 91% of thrombi in nonvalvular AF are localized in the left atrial appendage (LAA). Therefore, identification or exclusion of LAA thrombi is critical in many clinical situations. It is essential to assess LAA morphology and function using imaging modalities (particularly echocardiography) before, during, and after interventional procedures such as AF ablation and LAA occlusion. This review article describes the anatomical, physiological, and pathological background of the LAA, followed by an assessment of different echocardiographic modalities. Many practical points are included to improve the diagnostic accuracy and to minimize errors during image acquisition and interpretation. In each clinical scenario where LAA is the crucial target, specific and essential information and parameters are collected.

Modified Haller Index is inversely associated with asymptomatic status in atrial fibrillation patients undergoing electrical cardioversion: a preliminary observation

BACKGROUND

No previous study evaluated the possible influence of chest wall conformation on symptoms perception in atrial fibrillation (AF) patients candidates for electrical cardioversion (ECV). We aimed at evaluating the anthropometric and clinical characteristics of patients with persistent AF undergoing ECV, categorized according to the presence or absence of symptoms.

METHODS

This study retrospectively analyzed a series of persistent AF patients scheduled for early ECV who underwent pre-procedural clinical evaluation, MHI (the ratio of chest transverse diameter over the distance between sternum and spine) assessment, transthoracic and transesophageal echocardiography implemented with strain analysis of both left atrium and left atrial appendage. Thromboembolic risk and burden of comorbidities were assessed by CHA2DS2-VASc Score and Charlson Comorbidity Index (CCI), respectively. The independent predictors of "asymptomatic AF" were assessed.

RESULTS

A total of 25 asymptomatic and 90 symptomatic AF patients were retrospectively examined. Compared to symptomatic AF patients, those asymptomatic were significantly older (78.4±3.8 vs. 71.0±7.7 years, P<0.001), predominantly males (84 vs. 44.4%, P<0.001), with significantly lower MHI (2.0±0.1 vs. 2.4±0.1, P<0.001), higher CHA2DS2-VASc Score (5.8±1.1 vs. 3.6±1.1, P<0.001) and CCI (6.8±1.4 vs. 2.3±0.9, P<0.001), and greater impairment in biventricular systolic function and atrio-auricolar myocardial strain indices. On multivariate logistic regression analysis, CHA2DS2-VASc Score (OR=2.65, 95% CI: 1.53-4.60) and CCI (OR=2.36, 95% CI: 1.16-4.66) were linearly associated with the endpoint "asymptomatic AF," whereas MHI (OR 0.76, 95% CI 0.59-0.97) was inversely associated with the asymptomatic status. A MHI <2.2 was the best cut-off for detecting asymptomatic AF patients.

CONCLUSIONS

MHI is inversely associated with asymptomatic status in persistent AF patients undergoing ECV. MHI assessment might represent an innovative practical approach to AF patients.

Emergent Zero-Fluoroscopy Mapping and Thoracoscopic Ectomy of Appendage in Pregnant Women with Life-Threatening Atrial Tachycardia: A Case Report and Literature Review

Background: Focal atrial tachycardia (AT) originating from the right atrial appendage (RAA), often persistent and refractory, is clinically rare in pregnant woman, and the therapy is much more challenging. We report that a pregnant woman presented with hypotension due to persistent and refractory atrial tachycardia and was successfully cured by a multidisciplinary treatment (MDT) approach, consisting of a combination of zero-fluoroscopy mapping and thoracoscopic atrial appendectomy. We also carried out a literature review of this topic. Methods and Results: A 26-year-old woman in pregnancy at 21 weeks presented with severe palpitation and hypotension due to persistent rapid supraventricular tachycardia (SVT). Since adenosine triphosphate could not terminate the tachycardia, a catheter ablation procedure was planned and finally canceled when the zero-fluoroscopy mapping using Carto 3^TM system revealed an atrial tachycardia originating from the RAA. Thoracoscopic RAA ectomy was recommended after multidisciplinary consultation and successfully performed without fluoroscopy. Ensite^TM velocity mapping system was used for accurately locating the origin of the arrhythmia during ectomy. The woman finally produced a healthy baby during follow-up. Conclusions: Focal AT originating from appendage in pregnant patients can be persistent, refractory, and life-threatening; traditional strategies, such as medicine or catheter ablation, are limited in this situation. MDT measures, using a thoracoscopic ectomy and zero-fluoroscopy three-dimensional electroanatomical mapping technique, is minimally invasive and a promising strategy.

Left atrial function after standalone totally thoracoscopic left atrial appendage exclusion in atrial fibrillation patients with absolute contraindication to oral anticoagulation therapy

Background

Left atrial appendage (LAA) is a common source of thrombi in patients with atrial fibrillation (AF). The effect on left atrial (LA) function of the Totally Thoracoscopic (TT)-LAA exclusion with epicardial clip is currently unknown. This study aims at evaluating the effect of TT-LAA exclusion on LA function.

Methods

Standalone TT-LAA exclusion with the clip device was performed in 26 patients with AF and contraindication to oral anticoagulation (OAC). A 3D CT scan, trans-esophageal echocardiography, spirometry and cerebrovascular doppler ultrasound were performed preoperatively. Clip positioning and LAA exclusion were guided and confirmed by intraoperative trans-esophageal echo. To evaluate LA function, standard transthoracic echocardiography and 2D strain of LA were performed before surgery, at discharge and at 3-month follow-up.

Results

The mean CHA2DS2-VASc and HASBLED scores were 4.6 and 2.4 respectively. There were no major complications during the procedure. At median follow-up of 10.3 months, 1 (3.8%) non-cardiovascular death, 1 (3.8%) stroke and 4 (15.4%) cardiovascular hospitalizations occurred. At 2D strain of LA, the reservoir function decreased significantly at discharge, compared to baseline and recovered at 3-months follow-up. Furthermore, NT-proBNP increased significantly after the procedure with a return to baseline after 3 months. Changes in E/A were persistent at 3 months.

Conclusion

Our data in a small cohort suggest that TT-LAA exclusion with epicardial clip can be a safe procedure with regards to the atrial function. The LAA amputation impairs the reservoir LA function on the short term, that recovers over time.

Left atrial epicardial adipose tissue is closely associated with left atrial appendage flow velocity in patients with nonvalvular atrial fibrillation

Epicardial adipose tissue (EAT) can play an important role in the occurrence and development of atrial fibrillation and stroke. In this study, we explored the relationship between left atrial epicardial adipose tissue (LA-EAT) and left atrial appendage flow velocity (LAA-FV) in patients with nonvalvular atrial fibrillation (NV-AF). A total of 145 patients with NV-AF who underwent their first radiofrequency ablation were enrolled. They underwent left aortopulmonary vein computed tomography angiography (CTA) and transesophageal echocardiography (TEE) before AF ablation. Left atrial (LA) electroanatomical mapping was performed intraoperatively to assess left atrial voltage. Univariate regression analysis showed that LAA-FV was lower in patients with a low voltage zone (LAA-FV; 35.02 ± 10.78 cm/s vs. 50.60 ± 12.17 cm/s, P < 0.001). A multiple linear regression model showed that the left atrial low voltage zone (β = − 0.311 P < 0.001), LA-EAT volume (β = − 0.256 P < 0.001), left atrial appendage shape (β = − 0.216 P = 0.041), LAVI (β = − 0.153 P = 0.041), and type of atrial fibrillation (paroxysmal vs. persistence) (β = − 0.146 P < 0.048) were independent predictors of LAA-FV. In NV-AF patients, the increase in LA-EAT volume is related to the decrease in LAA-FV.

Transesophageal Echocardiography Following Left Atrial Appendage Electrical Isolation: Diagnostic Pitfalls and Clinical Implications

BACKGROUND

Following left atrial appendage (LAA) electrical isolation, the decision on whether to continue oral anticoagulation after successful atrial fibrillation ablation is based on the study of its mechanical function on transesophageal echocardiography (TEE). In this cohort, LAA contraction is absent and the incorrect interpretation of emptying flow velocities can lead to unwanted clinical sequelae.

METHODS

One hundred and sixty consecutive TEE exams performed to evaluate the LAA mechanical function following its electrical isolation were reviewed by an experienced operator blinded to the original diagnosis of LAA dysfunction. The rate of diagnostic discrepancy in the assessment LAA dysfunction and its clinical implications were evaluated.

RESULTS

Diagnostic discrepancy with misclassification of the LAA mechanical function occurred 36% (58/160) of TEE exams. In most cases (57/58), such discrepancy was observed in the setting of an incorrect original diagnosis of a normal LAA mechanical function despite absent/reduced or inconsistent LAA contraction. This main source of this wrong diagnosis was the wrong interpretation of passive LAA flows (34/57; 60%), followed by failure to identify dissociated firing (15/57; 26%). In rare cases (8/57; 14%), velocities of surrounding structures were interpreted as LAA flow due to misplacement of the pulsed-wave Doppler sample volume. Following LAA isolation, the proportion of patients who experienced a cerebrovascular event while off oral anticoagulation due to the misclassification of their LAA mechanical function was 70% (7/10 [95% CI, 40%-89%]).

CONCLUSIONS

Underdiagnosis of LAA mechanical dysfunction is common in TEEs performed following LAA electrical isolation, and it is associated with an increased risk of cerebrovascular events owing to oral anticoagulation discontinuation despite absent/reduced LAA contraction. Careful review of the TEE exam by an operator with specific expertise in LAA imaging and familiar with the functional implications of LAA isolation is necessary before interrupting oral anticoagulation in this cohort.

Proposal for a clinical and an echocardiographic score for prediction of left atrial thrombosis in atrial fibrillation patients undergoing early electrical cardioversion

AIMS

Left atrial thrombosis (LAT) is usually detected by transesophageal echocardiography (TEE). The aim of the present study was to identify clinical and echocardiographic factors associated with left atrial thrombosis in atrial fibrillation (AF) patients undergoing early electrical cardioversion (ECV) in order to create scores that can predict LAT, in a non-invasive way.

METHODS

A consecutive cohort of patients with persistent AF scheduled for ECV was evaluated by transthoracic echocardiography and TEE. By a logistic regression model, variables significantly associated with LAT were assessed and introduced in predictive models to develop both a clinical and an echocardiographic prediction score for the presence of LAT.

RESULTS

In total, 125 patients [median 71 (range 49-88) years, 60.0% males] were enrolled. Transesophageal echocardiography showed LAT in 35 patients (28%). The clinical variables significantly associated with LAT were previous stroke (OR = 4.17), higher CHA₂ DS₂ -VASc score (OR = 1.93), lower estimated glomerular filtration rate (OR = 0.80), and higher brain natriuretic peptide levels (OR = 1.44). Among echocardiographic parameters, E/e' ratio was directly associated with LAT (OR = 2.25), while an inverse correlation was detected with left ventricular ejection fraction (OR = 0.43) and total global left atrial strain (OR = 0.59). Two prediction scores (clinical and echocardiographic) were developed. The positive predictive values of the clinical and the echocardiographic score were 80% and 100%, respectively, while the negative predictive values were 98% and 94%, respectively. Combined use of the scores reached a positive and negative predictive value of 100%.

CONCLUSIONS

When providing concordant information the two scores are able to correctly identify patients with or without LAT. An external validation is necessary to demonstrate their usefulness in the clinical practice.

Mechanical concordance between left atrium and left atrial appendage in nonvalvular atrial fibrillation: can it be exploited to avoid transesophageal echocardiography prior to electrical cardioversion during Covid-19 pandemic?

Transesophageal echocardiography (TEE) is the gold standard for assessing left atrial appendage (LAA) mechanic and thrombosis (LAAT); however, TEE is a high-risk procedure for viral transmission during coronavirus disease 2019 (COVID-19) pandemic. We investigated whether deformation indices of left atrium (LA) at transthoracic echocardiography (TTE) correlate with those of LAA assessed by TEE in nonvalvular atrial fibrillation (NVAF) patients undergoing electrical cardioversion (ECV). Consecutive patients with NVAF of ≥ 48 h or unknown duration, who underwent TEE and TTE at our Institution before ECV were retrospectively investigated. Standard echo-Doppler and LA and LAA myocardial strain and strain rate parameters were analyzed. A total of 115 NVAF patients (71.3 ± 8.1 yr/o, 59.1% men) were included: LAAT was diagnosed in 25 (21.7%) patients. Compared to patients without LAAT, those with LAAT had significantly higher CHA₂DS₂-VASc Risk score (4.5 ± 1.4 vs. 3.5 ± 1.1, p < 0.001), and lower ejection fraction (46.0 ± 14.8 vs. 57.6 ± 8.6%, p < 0.001). In LAAT patients, global strain of LA (8.7 ± 2.6 vs. 16.3 ± 4.5%, p < 0.001) and LAA (7.0 ± 1.7 vs. 11.7 ± 2.0%, p < 0.001) was significantly reduced compared to non-LAAT patients. A close relationship between left atrial strain reservoir (LASr) and LAA-global strain was demonstrated (r = 0.81). By univariable analysis, CHA₂DS₂-VASc Risk Score (OR 2.01, 95%CI 1.34–3.00), NT-proBNP (OR 1.36, 95%CI 1.19–1.54), ejection fraction (OR 0.92, 95%CI 0.88–0.96), E/e’ ratio (OR 2.07, 95%CI 1.51–2.85), and LASr (OR 0.39, 95%CI 0.25–0.62) were strongly associated with LAAT presence at TEE. By multivariable analysis, only LASr (OR 0.40, 95%CI 0.24–0.70) retained statistical significance. ROC curve analysis revealed that an LASr cut-off value ≤ 9.3% had 98.9% sensibility and 100% specificity to identify LAAT by TEE (AUC = 0.98). In patients with NVAF of ≥ 48 h or unknown duration, scheduled to undergo ECV, LA deformation assessment by TTE might substitute invasive measurement of LAA function by TEE, simplifying diagnostic approach and possibly contributing to reduce COVID-19 infection diffusion.

A novel method to demonstrate thrombus formation of the left atrial appendage in patients with persistent atrial fibrillation by cardiac computed tomography

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We created a new algorism to detect a left atrial appendage (LAA) thrombus on CT.

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We measured HU density at one proximal (ostium) and seven distal sites of LAA.

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A distal/proximal ratio and a standard deviation of HU density were analyzed by ROC.

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Combination of the two parameters demonstrated a high accuracy for LAA thrombus.

Background

Transesophageal echocardiography (TEE) is currently the gold standard technique for diagnosing left atrial appendage (LAA) thrombi. Cardiac computed tomography (CT) has been expected to become an alternative method to TEE; however, a reliable quantitative evaluation method has not been established.

Methods and results

We enrolled 177 patients with persistent atrial fibrillation who underwent both cardiac CT and TEE before catheter ablation. The patients were classified into two groups according to the TEE results: the thrombus group (13 patients) and non-thrombus group (164 patients). The Hounsfield unit (HU) density at the proximal LAA (LAAp) and distal LAA (LAAd) was measured on cardiac CT images. The LAAd/LAAp HU ratio and standard deviation of HU density (HU-SD) at the LAAd were evaluated. We created an algorithm by decision tree analysis to predict LAA thrombus formation using the HU ratio and HU-SD. Definite absence of LAA thrombus (Category-I) was diagnosed for 139 patients by combining the first and second branching of the decision tree (Category-Ia: HU ratio of ≥0.26, Category-Ib: HU ratio of <0.26, HD-SD of ≥26.94). Definite presence of LAA thrombus (Category-Ⅱ) was diagnosed for 3 patients using the third branching of the decision tree (Category-Ⅱ: HU ratio of <0.26 and HU-SD of <13.85). Highly possibility of LAA thrombus (Category-III), but not definite, was diagnosed for the remaining 35 patients; therefore, these patients required diagnostic TEE. The diagnostic accuracy of this algorithm was 0.95.

Conclusion

We have proposed a reliable algorithm to diagnose LAA thrombus formation using the HU ratio and HU-SD.

EACVI recommendations on cardiovascular imaging for the detection of embolic sources: endorsed by the Canadian Society of Echocardiography

Cardioaortic embolism to the brain accounts for approximately 15-30% of ischaemic strokes and is often referred to as 'cardioembolic stroke'. One-quarter of patients have more than one cardiac source of embolism and 15% have significant cerebrovascular atherosclerosis. After a careful work-up, up to 30% of ischaemic strokes remain 'cryptogenic', recently redefined as 'embolic strokes of undetermined source'. The diagnosis of cardioembolic stroke remains difficult because a potential cardiac source of embolism does not establish the stroke mechanism. The role of cardiac imaging-transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE), cardiac computed tomography (CT), and magnetic resonance imaging (MRI)-in the diagnosis of potential cardiac sources of embolism, and for therapeutic guidance, is reviewed in these recommendations. Contrast TTE/TOE is highly accurate for detecting left atrial appendage thrombosis in patients with atrial fibrillation, valvular and prosthesis vegetations and thrombosis, aortic arch atheroma, patent foramen ovale, atrial septal defect, and intracardiac tumours. Both CT and MRI are highly accurate for detecting cavity thrombosis, intracardiac tumours, and valvular prosthesis thrombosis. Thus, CT and cardiac magnetic resonance should be considered in addition to TTE and TOE in the detection of a cardiac source of embolism. We propose a diagnostic algorithm where vascular imaging and contrast TTE/TOE are considered the first-line tool in the search for a cardiac source of embolism. CT and MRI are considered as alternative and complementary tools, and their indications are described on a case-by-case approach.

Evaluating the novel parameters for assessing the LAA function and thrombus formation with nonvalvular atrial fibrillation

The dysfunction of left atrial appendage (LAA) is prone to form thrombus when atrial fibrillation (AF) sustained more than 48 h. Traditional 2D-TEE (transesophageal echocardiography) can not accurate evaluate the function of LAA. The purpose of this study is to analyze the relationship of LAA function parameters and thrombus formation in patients with non-valvular atrial fibrillation (NVAF) by real-time three-dimensional transesophageal echocardiography (RT-3D-TEE). High risk patients can be identified according to the characteristics of ultrasonic index in patients with left atrial appendage thrombosis, which has important clinical value and significance in the risk assessment, guiding treatment and judging prognosis. We examined the relationship between the echocardiographic parameters of LAA function and the incidence of thrombus in 102 NVAF patients. They underwent RT-3D-TEE and left atrial appendage thrombus (LAAT)/severe spontaneous echocardiographic contrast (SSEC) was found in 67 patients (thrombus group) but absent in the remaining 35 patients (non-thrombus group). After measured by QLAB software, the LAA functional parameters were significantly associated with LAAT/SEC formation. Univariate analysis indicated that AF time, LAD, LVEF, LAA-OAmax, LAAVmax, LAAVI and LAAEF demonstrated a positive association (P < 0.05). However, logistic regression analysis identified that AF time (OR:1.73, P < 0.05)、LAAEF (OR:4.09, P < 0.01)and LAAVI (OR:3.28, P < 0.01) were independent predictors of LAAT/SSEC. In patients with nonvalvular atrial fibrillation, echocardiographic parameters of LAA function are significantly associated with LAAT/SSEC.

Predictors for reduced flow velocity in left atrial appendage during sinus rhythm in patients with atrial fibrillation

Discontinuation of anticoagulation therapy after catheter ablation (CA) for atrial fibrillation (AF) remains controversial. While decreased left atrial appendage flow velocity (LAAFV) during AF leads to left atrial appendage thrombus and embolic events, some AF patients show decreased LAAFV even during sinus rhythm (SR). We studied 392 patients (256 males, 68 ± 10 years) who exhibited SR during transesophageal echocardiography (TEE) before CA for AF. Clinical factors, transthoracic echocardiography, and blood samples were obtained before TEE. Reduced LAAFV was defined as < 35 cm/s of LAAFV. Reduced LAAFV was observed in 72/392 patients (18%). Reduced LAAFV was significantly associated with high prevalence of non-paroxysmal AF, elevated brain natriuretic peptide (BNP), prior heart failure, high CHADS₂ score, high CHA₂DS₂-VASc score, no beta blocker administration, increased left atrial volume index (LAVI), elevated E/e' ratio, reduced left ventricular ejection fraction and high prevalence of left ventricular hypertrophy. On multivariate analysis, BNP (P = 0.0005, OR 1.045 for each 10 pg/ml increase in BNP, 95% CI 1.018-1.073) and LAVI (P = 0.0045, OR 1.044 for each 1 increase in LAVI, 95% CI 1.013-1.077) were associated with decreased LAAFV. The elevated BNP levels and large LAVI predict decreased LAAFV during SR in patients with AF.

Left atrial appendage morphology and cardiac function in patients with sinus rhythm

BACKGROUND

The left atrial appendage (LAA) is one of the major sources of cardiac thrombus formation. The morphology of the LAA correlates with stroke in patients with atrial fibrillation. In this study, we evaluated the correlation between LAA morphology and cardiac function by transthoracic echocardiography in patients with sinus rhythm.

METHODS AND RESULTS

We studied 55 patients (36 men, 70 ± 11 years) who underwent cardiac computed tomography and transthoracic echocardiography. The following 4 different morphologies were used to categorize LAA by computed tomography: chicken wing (CW), windsock, cactus, and cauliflower. These morphologies were also classified into CW and non-CW (nonCW) types. There were no significant differences in the left ventricular ejection fraction (63% vs 62%), left atrial (LA) volume (22.2 vs 25.5 ml/m²), and LAA volume (4.3 vs 4.7 ml/m²) between nonCW and CW. Patients with nonCW showed a lower A' velocity (8.0 vs 9.3 cm/s, p < 0.01), worse global longitudinal strain (- 17.2 vs - 20.2%, p < 0.01), lower tissue mitral annular displacement (9.7 vs 11.1 mm, p = 0.01), and lower LAS strain (22.6 vs 34.5%, p < 0.01) by speckle tracking echocardiography than did those with CW. Multiple logistic analysis showed that nonCW LAA morphology was closely associated with lower LAS strain. Furthermore, a change in volume of the LAA during the cardiac cycle was lower in nonCW than in CW.

CONCLUSIONS

These findings suggest that impaired LA and LAA functions are related to changes of the LAA in patients with sinus rhythm.

Biomarkers of Atrial Fibrillation in Hypertension

Background:

Atrial fibrillation (AF) is the most frequently encountered cardiac arrhythmia globally and substantially increases the risk for thromboembolic disease. Albeit, 20% of all cases of AF remain undiagnosed. On the other hand, hypertension amplifies the risk for both AF occurrences through hemodynamic and non-hemodynamic mechanisms and cerebrovascular ischemia. Under this prism, prompt diagnosis of undetected AF in hypertensive patients is of pivotal importance.

Method:

We conducted a review of the literature for studies with biomarkers that could be used in AF diagnosis as well as in predicting the transition of paroxysmal AF to sustained AF, especially in hypertensive patients.

Results:

Potential biomarkers for AF can be broadly categorized into electrophysiological, morphological and molecular markers that reflect the underlying mechanisms of adverse atrial remodeling. We focused on P-wave duration and dispersion as electrophysiological markers, and left atrial (LA) and LA appendage size, atrial fibrosis, left ventricular hypertrophy and aortic stiffness as structural biomarkers, respectively. The heterogeneous group of molecular biomarkers of AF encompasses products of the neurohormonal cascade, including NT-pro BNP, BNP, MR-pro ANP, polymorphisms of the ACE and convertases such as corin and furin. In addition, soluble biomarkers of inflammation (i.e. CRP, IL-6) and fibrosis (i.e. TGF-1 and matrix metalloproteinases) were assessed for predicting AF.

Conclusion:

The reviewed individual biomarkers might be a valuable addition to current diagnostic tools but the ideal candidate is expected to combine multiple indices of atrial remodeling in order to effectively detect both AF and adverse characteristics of high risk patients with hypertension.

Regional Disparities of Left Atrial Appendage Wall Contraction in Patients With Sinus Rhythm and Atrial Fibrillation

BACKGROUND

Patients with atrial fibrillation (AF) exhibit impaired left atrial appendage (LAA) function. However, regional characteristics of LAA function in patients with AF are not defined.

METHODS

Consecutive patients (n = 1,195) undergoing transesophageal echocardiography at a university hospital were included. Patients were divided into three groups on the basis of their rhythm: sinus rhythm (SR), paroxysmal AF, and permanent or persistent AF. Regional LAA wall velocities were determined using color Doppler tissue imaging, placing regions of interest at the lateral and medial wall of the LAA.

RESULTS

Of the 1,182 patients ultimately included, 691 (59%) were in SR, 371 (32%) had permanent or persistent AF, and 120 (10%) had paroxysmal AF with SR at the time of transesophageal echocardiography. Both lateral and medial LAA wall velocities were lower in patients with AF in comparison with those in SR. Nearly 90% of patients in both groups of patients with AF exhibited a pattern of medial LAA wall velocity greater than lateral LAA wall velocity, in comparison with 20% of patients with SR. The odds ratio for the association of this LAA contraction pattern with AF was 22.14 (95% CI, 12.06-40.64; P < .001). The movement of lateral LAA wall velocity showed the highest correlation with LAA emptying velocity compared with the medial LAA wall (r = 0.67, P < .001).

CONCLUSIONS

Lateral LAA wall velocity is higher than medial LAA wall velocity in patients in SR, which reverses in patients with AF. Assessment of LAA regional wall velocity using Doppler tissue imaging appears to be a promising approach to identify patients with paroxysmal AF.

Real-time surveillance of left atrial appendage thrombus during contrast computed tomography imaging for catheter ablation: THe Reliability of cOMputed tomography Beyond UltraSound in THROMBUS detection (THROMBUS) study

Left atrial contrast computed tomography (LA-CT) as well as transesophageal echocardiography (TEE) can exclude left atrial appendage (LAA) thrombus, but is sometimes unable to evaluate LAA due to incomplete LAA filling. The aim of the current study was to validate the utility of real-time approach of LA-CT with real-time surveillance of LAA-filling defect (FD). We enrolled consecutive 894 patients with LA-CT studies acquired for catheter ablation and compared the diagnostic accuracy in demonstrating LAA-FD between conventional protocol (N = 474) and novel protocol with real-time surveillance of LAA-FD immediately after the initial scanning and, when necessary, adding delayed scanning in the supine or prone position (N = 420). Primary endpoint was severity of LAA-FD classified into the 3 groups: "Grade-0" for complete filling of contrast, "Grade-1" for incomplete filling of contrast, and "Grade-2" for complete FD of contrast. The prevalence of Grade-1 and Grade-2 FD was 17.3% and 11.2% in conventional protocol, whereas there was no patient with Grade-2 FD, and only 1 patient with Grade-1 FD after the additional scanning in novel protocol. In 5 patients with suspected LAA thrombus both by TEE and Grade-2 FD in LA-CT by the conventional protocol, ablation procedure was canceled due to diagnosis of LAA thrombus. Conversely, 4 patients with suspected LAA thrombus by TEE in novel protocol group was proved to have intact LAA by LA-CT with and without additional scanning. This novel approach with real-time surveillance improved the diagnostic accuracy of LA-CT in detecting LAA-FD, suggesting potential superiority of LA-CT over TEE in excluding LAA thrombus.

Impact of atrial fibrillation on in-hospital mortality of ischemic stroke patients and identification of promoting factors of atrial thrombi - Results from the German nationwide inpatient sample and a single-center retrospective cohort

Ischemic stroke is one of the leading causes of death and disability. Atrial fibrillation (AF) is a well-recognized risk factor for ischemic stroke.We aimed to investigate the impact of AF on in-hospital mortality of ischemic stroke patients and to identify parameters associated with intra-cardiac thrombogenic material.Patients were selected by screening the nationwide sample for ischemic stroke by ICD-Code (I63), stratified for AF. In this cohort, the association between in-hospital deaths and AF was investigated.In a second study, we performed a retrospective analysis of patients who underwent transesophageal echocardiography (TEE) for various reasons, assigned these to 2 groups based on the heart-rhythm (sinus-rhythm [SR] vs AF) and examined associations between clinical and echocardiographic parameters and intra-cardiac thrombogenic material.The Nationwide sample comprised 292,401 inpatients (48.5% females) with ischemic stroke. Incidence was 360 per 100,000 citizens, with an age-dependent increase. In-hospital mortality rate was 8.2%; AF patients had 1.85-fold higher mortality rate (12.1% vs 6.5%).In the retrospective study, 219 patients (median age 67 [59.1-77.3] years, 39.3% females) were included: 115 patients with AF (median age 71 [59.0-78.0] years, 41.7% females) and 104 patients (median age 68 [56.3-76.8] years, 36.5% females) with SR. Solid thrombus or spontaneous-echo-contrast) was detected in 16 TEEs. Atrial dimensions were significantly enlarged in AF patients. Age, blood-flow velocity in LAA, LAA diameters, atrial areas, AF, and CHA2DS2-VASc-score were associated with thrombogenic material.Incidence of ischemic stroke increased with age. AF was connected with higher stroke mortality. Presence of intra-cardiac thrombogenic material was associated with AF and most CHA2DS2-VASc-score factors. AF was associated with larger atrial dimensions and larger cavities favored thrombogenic material.

Correlation between plasma brain natriuretic peptide levels and left atrial appendage flow velocity in patients with non-valvular atrial fibrillation and normal left ventricular systolic function

BACKGROUND

The left atrial appendage (LAA) flow velocity is an important factor for thrombus formation in patients with non-valvular atrial fibrillation (NV-AF). Recently, the relation of plasma brain natriuretic peptide (BNP) levels and thromboembolism has been reported in patients with NV-AF. The aim of this study was to determine whether the plasma BNP is predictive of lower LAA flow velocity in patients with NV-AF and normal left ventricular (LV) systolic function.

METHODS AND RESULTS

A total of 184 patients with NV-AF (132 men; 65 ± 12 years, LV ejection fraction; 65 ± 10%) underwent transthoracic echocardiography, transesophageal echocardiography (TEE), and measurement of plasma BNP. The LAA flow velocity was obtained by pulsed Doppler TEE. Multivariate logistic regression analysis demonstrated that plasma BNP levels, left atrial volume index (LAVI), LV mass index (LVMI), and the CHADS₂ score were independent predictors of lower LAA flow velocity (< 20 cm/s). Plasma BNP levels (r = - 0.58, p < 0.001) were correlated with LAA flow velocity. The area under the curve (AUC) for BNP (AUC 0.803) was larger than that for the CHADS₂ score (AUC 0.712), LAVI (AUC 0.664) and LVMI (AUC 0.608) with an optimal BNP cut-off value of 164 pg/ml (sensitivity 75.7%, specificity 71.1%).

CONCLUSIONS

This study showed that a higher plasma BNP was associated with a lower LAA flow velocity in patients with NV-AF and normal LV systolic function. The plasma BNP may complement the role of the CHADS₂ score in predicting lower LAA flow velocity.

CT based 3D printing is superior to transesophageal echocardiography for pre-procedure planning in left atrial appendage device closure

Accurate assessment of the left atrial appendage (LAA) is important for pre-procedure planning when utilizing device closure for stroke reduction. Sizing is traditionally done with transesophageal echocardiography (TEE) but this is not always precise. Three-dimensional (3D) printing of the LAA may be more accurate. 24 patients underwent Watchman device (WD) implantation (71 ± 11 years, 42% female). All had complete 2-dimensional TEE. Fourteen also had cardiac computed tomography (CCT) with 3D printing to produce a latex model of the LAA for pre-procedure planning. Device implantation was unsuccessful in 2 cases (one with and one without a 3D model). The model correlated perfectly with implanted device size (R² = 1; p < 0.001), while TEE-predicted size showed inferior correlation (R² = 0.34; 95% CI 0.23-0.98, p = 0.03). Fisher's exact test showed the model better predicted final WD size than TEE (100 vs. 60%, p = 0.02). Use of the model was associated with reduced procedure time (70 ± 20 vs. 107 ± 53 min, p = 0.03), anesthesia time (134 ± 31 vs. 182 ± 61 min, p = 0.03), and fluoroscopy time (11 ± 4 vs. 20 ± 13 min, p = 0.02). Absence of peri-device leak was also more likely when the model was used (92 vs. 56%, p = 0.04). There were trends towards reduced trans-septal puncture to catheter removal time (50 ± 20 vs. 73 ± 36 min, p = 0.07), number of device deployments (1.3 ± 0.5 vs. 2.0 ± 1.2, p = 0.08), and number of devices used (1.3 ± 0.5 vs. 1.9 ± 0.9, p = 0.07). Patient specific models of the LAA improve precision in closure device sizing. Use of the printed model allowed rapid and intuitive location of the best landing zone for the device.

Lower Body Weight in Men, an Epidemiological Predictor of Enlarged Left Atrium in Sinus Rhythm Patients with Dilated Heart

BACKGROUND/AIMS

The source of thrombi in patients with dilated cardiomyopathy is not necessarily from the dilated left ventricle. Left atrium (LA) and left atrial appendage (LAA) might be in charge for relatively high rate of systemic embolizations in these patients. The main aim of our study was to identify epidemiological predictors in sinus rhythm patients with dilated heart for LA and LAA dilation and/or dysfunction.

PATIENTS AND METHODS

This was a prospective cross-sectional study conducted from 2009 to 2014 in 101 sinus rhythm patients with dilated heart. We excluded patients with swallowing problems, acute myocardial infarction, atrial fibrillation/flutter, severe systolic dysfunction, mechanical valves, oral anticoagulation therapy, and/or patients with a history of stroke/systemic thromboembolic event.

RESULTS

Mean patient age was 58.13 ± 12.66 years and 69.3% were men. Hypertension was encountered in 51% of our patients, 56% of them had a history of coronary artery disease, 30% had diabetes, 25% had dyslipidemia, 30% were smokers, whereas 10% were alcoholics. Mean LA dimensions resulted higher than reference values, whereas 86% of our patients had LAA dysfunction. Male gender was an independent predictor for LA diameter dilation (95% confidence interval [CI]: 1.765-9.078, P = 0.005), while lower body weight was a predictor for enlargement of LA area (95% CI: 0.044-0.351, P = 0.014) and LA volume (95% CI: 0.160-2.067, P = 0.024).

CONCLUSION

Male patients with dilated cardiomyopathy at sinus rhythm with lower body weight tend to have larger LA and consequently might be at higher risk of developing atrial thrombus and its subsequent consequences.

Underdevelopment of Left Atrial Appendage

A patient was admitted for catheter ablation of atrial fibrillation. Cardiac computed tomography and transesophageal echocardiography revealed the absence of the left atrial appendage. However, the right atrial appendage looked normal and the level of pro B-natriuretic peptide was within normal limits. Successful catheter ablation was performed without any procedural complications and the sinus rhythm was appropriately maintained for 10 months with an antiarrhythmic drug.

Characteristics of Anatomy and Function of the Left Atrial Appendage and Their Relationships in Patients with Cardioembolic Stroke: A 3-Dimensional Transesophageal Echocardiography Study

BACKGROUND

Increasing attention is being paid to the left atrial appendage (LAA) in the context of risk stratification in cardioembolic stroke (CES) and the requirement for meticulous planning of percutaneous closure device implantation. However, detailed systematic assessment of the LAA remains limited.

METHODS

This study evaluated the anatomy and function of LAA using 3-dimensional transesophageal echocardiography (3D-TEE) on 194 consecutive patients older than 50 years old hospitalized exclusively for CES. Patients were stratified into 3 groups on the basis of cardiac rhythm: (1) chronic atrial fibrillation (AF), n = 53; (2) paroxysmal AF, n = 26; and (3) no detected AF, n = 115.

RESULTS

Significant differences between the groups were observed for anatomical (orifice area [OA], depth, diastolic volume) and functional parameters (ejection fraction [EF], flow velocity [FV]), as measured by 3D-TEE. The anatomical parameters were consistently the greatest, and functional parameters were the poorest, in the group with chronic AF. There were significant inverse correlations between them (r = -.33, P = .0003 for depth and EF; r = -.27, P = .0020 for depth and FV; r = -.22, P = .016 for OA and EF; and r = -.38, P < .0001 for OA and FV).

CONCLUSIONS

LAA morphology and function were strongly affected by cardiac rhythm disturbances. Patients with chronic AF had the greatest LAA dimensions, areas, and volumes as well as the lowest LAA functions. An inverse correlation was observed between LAA size and function.

Rotational method simplifies 3-dimensional measurement of left atrial appendage dimensions during transesophageal echocardiography

Background

Not all echo laboratories have the capability of measuring direct online 3D images, but do have the capability of turning 3D images into 2D ones “online” for bedside measurements. Thus, we hypothesized that a simple and rapid rotation of the sagittal view (green box, x-plane) that shows all needed left atrial appendage (LAA) number of lobes, orifice area, maximal and minimal diameters and depth parameters on the 3D transesophageal echocardiography (3DTEE) image and LAA measurements after turning the images into 2D (Rotational 3DTEE/“Yosefy Rotation”) is as accurate as the direct measurement on real-time-3D image (RT3DTEE).

Methods

We prospectively studied 41 consecutive patients who underwent a routine TEE exam, using QLAB 10 Application on EPIQ7 and IE33 3D-Echo machine (BORTHEL Phillips) between 01/2013 and 12/2015. All patients underwent 64-slice CT before pulmonary vein isolation or for workup of pulmonary embolism. LAA measurements were compared between RT3DTEE and Rotational 3DTEE versus CT.

Results

Rotational 3DTEE measurements of LAA were not statistically different from RT3DTEE and from CT regarding: number of lobes (1.6 ± 0.7, 1.6 ± 0.6, and 1.4 ± 0.6, respectively, p = NS for all); internal area of orifice (3.1 ± 0.6, 3.0 ± 0.7, and 3.3 ± 1.5 cm², respectively, p = NS for all); maximal LAA diameter (24.8 ± 4.5, 24.6 ± 5.0, and 24.9 ± 5.8 mm, respectively, p = NS for all); minimal LAA diameter (16.4 ± 3.4, 16.7 ± 3.3, and 17.0 ± 4.4 mm, respectively, p = NS for all), and LAA depth (20.0 ± 2.1, 19.8 ± 2.2, and 21.7 ± 6.9 mm, respectively, p = NS for all).

Conclusion

Rotational 3DTEE method for assessing LAA is a simple, rapid and feasible method that has accuracy similar to that of RT3DTEE and CT. Thus, rotational 3DTEE (“Yosefy rotation”) may facilitate LAA closure procedure by choosing the appropriate device size.

Percutaneous interventions for left atrial appendage exclusion: options, assessment, and imaging using 2D and 3D echocardiography

Percutaneous left atrial appendage (LAA) exclusion is an evolving treatment to prevent embolic events in patients with nonvalvular atrial fibrillation. In the past few years multiple percutaneous devices have been developed to exclude the LAA from the body of the left atrium and thus from the systemic circulation. Two- and 3-dimensional transesophageal echocardiography (TEE) is used to assess the LAA anatomy and its suitability for percutaneous closure to select the type and size of the closure device and to guide the device implantation procedure in conjunction with fluoroscopy. In addition, 2- and 3-dimensional TEE is also used to assess the effectiveness of device implantation acutely and on subsequent follow-up examination. Knowledge of the implantation options that are currently available along with their specific characteristics is essential for choosing the appropriate device for a given patient with a specific LAA anatomy. We present the currently available LAA exclusion devices and the echocardiographic imaging approaches for evaluation of the LAA before, during, and after LAA occlusion.

Left Atrial Appendage Closure -The WATCHMAN Device

Atrial fibrillation (AF) is one of the most common arrhythmias seen in clinical cardiology practice. Patients with non-valvular AF have an approximately 5-fold increase in the risk of stroke, with an exponential increase with advancing age. Cardioembolic strokes carry a high mortality risk. Although the potential of warfarin to reduce systemic embolization in AF patients is well established, its use is difficult due to narrow therapeutic windows and additional complications (e.g. increased risk of bleeding), especially for aging patients. Therefore, alternative means of treatment to reduce stroke risk in these patients are needed. The left atrial appendage is the major source of thrombus formation in patients with non-valvular AF. The WATCHMAN device (Boston Scientific, MA) is a percutaneous left atrial appendage closure device which has been tested prospectively in multiple randomized trials. It offers a new stroke risk reduction option for high-risk patients with non-valvular atrial fibrillation who are seeking an alternative to long-term warfarin therapy. Based on the robust WATCHMAN clinical program which consists of numerous studies, with more than 2,400 patients and nearly 6,000 patient-years of follow-up, the WATCHMAN LAAC Device is approved by FDA. In this article we reviewed the preclinical studies and clinical trials, as well as the next generation of the device.

Assessment of normal left atrial appendage anatomy and function over gender and ages by dynamic cardiac CT

OBJECTIVES

The aim of this study was to evaluate variations in anatomy and function according to age and gender using cardiac computed tomography (CT) in a large prospective cohort of healthy patients.

BACKGROUND

The left atrial appendage (LAA) is considered the most frequent site of intracardiac thrombus formation. However, variations in normal in vivo anatomy and function according to age and gender remain largely unknown.

METHODS

Three-dimensional (3D) cardiac reconstructions of the LAA were performed from CT scans of 193 consecutive patients. Parameters measured included LAA number of lobes, anatomical position of the LAA tip, angulation measured between the proximal and distal portions, minimum (iVolmin) and maximum (iVolmax) volumes indexed to body surface area (BSA), and ejection fraction (LAAEF). Relationship with age was assessed for each parameter.

RESULTS

We found that men had longer and wider LAAs. The iVolmin and iVolmax increased by 0.23 and 0.19 ml per decade, respectively, while LAAEF decreased by 2% per decade in both sexes.

CONCLUSIONS

Although LAA volumes increase, LAAEF decreases with age in both sexes.

KEY POINTS

• Variations in normal left atrial appendage in vivo anatomy and function remain largely unknown. • Cardiac CT is reliable for left atrial appendage volume measurements. • Although LAA volumes increase, LAAEF decreases with age in both sexes.

Improvement of Predictive Value for Thromboembolic Risk by Incorporating Left Atrial Functional Parameters in the CHADS2 and CHA2DS2-VASc Scores

The discriminative ability of the widely used CHADS2 and CHA2DS2-VASc scores for risk stratification of thromboembolism in atrial fibrillation (AF) is known as modest. Some echocardiographic parameters are known risk factors for thromboembolism. This study aimed to evaluate whether combining echocardiographic parameters with CHADS2 and CHA2DS2-VASc scores can improve the predictive power for embolic risk in AF.A total of 526 (F/M = 83/433, mean age = 57.6 ± 10.7 years) patients with non-valvular AF were enrolled. The predictability for left atrial (LA) thrombus or dense spontaneous echo contrast (SEC) using clinical scores or echocardiographic parameters or combining clinical scores and echocardiographic parameters was calculated and compared.Dense SEC or thrombus was present in 51 patients. The predicting powers of the CHADS2 and CHADS2-VASc scores for the presence of dense SEC or thrombus were modest (c-statistics 0.65 and 0.68, respectively, 95% confidence interval [CI] 0.61-0.69 and 0.64-0.74, respectively, both P < 0.001). Impaired LA function was the most descriptive predictor for the presence of thrombus or dense SEC among echocardiographic parameters. Combining impaired LA function (LA emptying fraction < 30%) with the CHADS2 and CHA2DS2-VASc scores showed the improvement of predictive power in detecting dense SEC or thrombus (c-statistics 0.78 and 95% CI 0.74-0.81 and c-statistics 0.77 and 95% CI 0.73-0.81, respectively, both P < 0.001).Adding LA functional markers to the CHADS2 or CHA2DS2-VASc score improved the predictive value of the presence of thrombus or dense SEC. In clinical situations, anticoagulation should be considered to prevent embolism in patients with low-risk scores when they have LA dysfunction.

Techniques To Improve Left Atrial Appendage Imaging

The clinical importance of the left atrial appendage (LAA) is increasingly recognized. The assessment of the unique anatomy and function of the LAA is especially important in the setting of atrial fibrillation (AF). AF is the most commonly occurring cardiac arrhythmia, and the association of LAA thrombi and AF has been well established. Transesophageal echocardiography (TEE) is a widely available imaging tool to exclude the potential presence of LAA thrombus prior to cardioversion in patients with AF. Commercially available products containing microbubbles to enhance ultrasound images, termed "ultrasound contrast agents" (UCA) are indicated for use with transthoracic echocardiography to improve cardiac structure and function assessment, but can also be used with TEE as an adjunctive tool to assess the LAA. Integrative multimodality imaging techniques can be used in evaluation of the LAA as indicated in various clinical scenarios including: stroke risk assessment, decision-making prior to cardioversion in AF, placement and assessment percutaneous transcatheter LAA occlusion procedures, and assessment of results of procedural or surgical exclusion of LAA. In this article, various imaging techniques that are available for non-invasive visualization of the LAA will be reviewed along with the clinical importance of assessment of LAA anatomy and function.

Role of Transesophageal Echocardiography in Left Atrial Appendage Device Closure

Left atrial appendage (LAA) occlusion or ligation by percutaneously implanted devices is increasingly an alternative management option for atrial fibrillation, particularly for patients who are intolerant or have contraindications for anticoagulation. Echocardiography plays an important part in screening, guidance of implantation, and after-device assessment. Assessment of LAA anatomy suitable for device implantation, thrombus exclusion, guidance of transseptal puncture, localization of catheter, guidance of device deployment, and after-device assessment are all important functions of echocardiography. This article reviews the role of echocardiography in device-based LAA occlusion or ligation.

Managing the Left Atrial Appendage in the Era of Minimally Invasive Surgery

Atrial fibrillation (AF) is the most prevalent arrhythmia encountered in clinical practice with greater than 2.2 million people in the United States being affected. Oral anticoagulant therapy has been used to reduce risk of stroke in patients with nonvalvular AF who are at a high risk of thromboembolism. Alternative treatment strategies to prevent thromboembolism have been tested in patients with AF. This article examines the history of left atrial appendage occlusion and the efficacy of the various surgical techniques and provides a brief overview of the minimally invasive surgical strategy adopted to manage the left atrial appendage.

Management of focal atrial tachycardias originating from the atrial appendage with the combination of radiofrequency catheter ablation and minimally invasive atrial appendectomy

BACKGROUND

Focal atrial tachycardias (ATs) originating from the left and the right atrial appendage (AA) were the most difficult to eliminate.

OBJECTIVE

To evaluate the safety and long-term efficacy of minimally invasive surgical atrial appendectomy in combination with radiofrequency catheter ablation (RFCA) in the management of focal atrial appendage tachycardias (AATs).

METHODS

We included 42 consecutive patients with 42 AATs confirmed by activation mapping and contrast venography. Thirty of them were successfully managed with RFCA (RFCA-successful group), while the remaining 12 (28.6%) finally resorted to video-assisted thoracoscopic atrial appendectomy owing to RFCA failure (resort-to-surgery group). We searched for predictors of RFCA failure, and the need for surgery by using a binomial logistic regression model.

RESULTS

In the RFCA-successful group, 6 (20.0%) patients experienced recurrence and re-do ablation and 11 (36.7%) AATs originated from distal AAs. In the resort-to-surgery group, the tachycardias involved exclusively distal AAs and required more RFCA attempts compared with those of the RFCA-successful group (1.58 ± 0.51 vs 1.20 ± 0.41; P = .0165). During atrial appendectomy, incessant ATs were terminated immediately after resection of the AA at the base. Long-term success was achieved in all 42 patients with a follow-up of 29.1 ± 17.5 months. No complications occurred. Fourteen patients with tachycardia-induced cardiomyopathy recovered fully. We identified origin at distal AATs and longer time to tachycardia termination by ablation as predictors of RFCA failure and the need for surgical intervention.

CONCLUSION

ATs originating from the distal portion of AA were more refractory to RFCA. The combination of catheter ablation and video-assisted thoracoscopic atrial appendectomy was an effective strategy to manage AATs.

Left ventricular mass predicts left atrial appendage thrombus in persistent atrial fibrillation

AIMS

Atrial fibrillation (AF) can result in the development of left atrial appendage (LAA) thrombi. We sought to examine demographic and echocardiographic predictors of LAA thrombus in patients with persistent AF.

METHODS AND RESULTS

One hundred and sixty-five patients in persistent AF (36 with LAA thrombus and 129 without thrombus) were studied. Demographic and cardiovascular risk factors were retrospectively examined. Transthoracic (TTE) and transoesophageal echocardiography (TOE) were performed to assess the size and function of the left ventricle (LV), left atrium (LA), LAA, and spontaneous echo contrast (SEC) in the LA and right atrium (RA). Univariate demographic predictors of LA thrombus included systolic blood pressure, ischaemic heart disease and congestive heart failure. Indexed LV mass and septal E' velocity on TTE and mean LAA emptying velocity and the presence of SEC in both the LA and RA on TOE were predictors of thrombus. In a multiple logistic regression analysis the only independent predictor of thrombus was indexed LV mass (P < 0.001). Receiver operator characteristic curve analysis also demonstrated that indexed LV mass had the highest area under the curve (AUC: 0.98).

CONCLUSION

In the present study, increased LV mass was the strongest predictor of LAA thrombus in persistent AF. LA SEC and RA SEC were univariate predictors of LAA thrombus but did not add predictive value to a multivariate model including LV mass. This study highlights the importance of diagnosing and treating LV hypertrophy associated with persistent AF, which may reduce the risk of LAA thrombus and thrombo-embolic stroke.

Velocity encoded cardiovascular magnetic resonance to assess left atrial appendage emptying

BACKGROUND

The presence of impaired left atrial appendage (LAA) function identifies patients who are prone to thrombus formation in the LAA and therefore being at high risk for subsequent cardioembolic stroke. LAA function is typically assessed by measurements of LAA emptying velocities using transesophageal echocardiography (TEE) in clinical routine. This study aimed at evaluating the feasibility of assessing LAA emptying by velocity encoded (VENC) cardiovascular magnetic resonance (CMR).

METHODS

This study included 30 patients with sinus rhythm (n = 18) or atrial fibrillation (n = 12). VENC-CMR velocity measurements were performed perpendicular to the orifice of the LAA. Peak velocities were measured of passive diastolic LAA emptying (e-wave) in all patients. Peak velocities of active, late-diastolic LAA emptying (a-wave) were assessed in patients with sinus rhythm. Correlation and agreement was analyzed between VENC-CMR and TEE measurements of e- and a-wave peak velocities.

RESULTS

A significant correlation and good agreement was found between VENC-CMR and TEE measurements of maximal e-wave velocities (r = 0.61, P < 0.001; mean difference 0 ± 10 cm/s). The a-wave was detectable by VENC-CMR in all patients with sinus rhythm. Correlation was also significant for measurements of peak a-wave velocities between VENC-CMR and TEE (r = 0.71, P < 0.001). There was no significant correlation of LAA emptying velocities with clinical characteristics and only a modest negative correlation of passive LAA emptying with LA function.

CONCLUSIONS

The assessment of active and passive LAA emptying by VENC-CMR is feasible. Further evaluation is required of potential future clinical applications such as risk stratification for cardioembolic stroke.

Correlation of right atrial appendage velocity with left atrial appendage velocity and brain natriuretic Peptide

Background

Left atrial appendage (LAA) anatomy and function have been well characterized both in healthy and diseased people, whereas relatively little attention has been focused on the right atrial appendage (RAA). We sought to evaluate RAA flow velocity and to compare these parameters with LAA indices and with a study of biomarkers, such as brain natriuretic peptide, among patients with sinus rhythm (SR) and atrial fibrillation (AF).

Methods

In a series of 79 consecutive patients referred for transesophageal echocardiography, 43 patients (23 with AF and 20 controls) were evaluated.

Results

AF was associated with a decrease in flow velocity for both LAA and RAA [LAA velocity-SR vs. AF: 61 ± 22 vs. 29 ± 18 m/sec (p < 0.01), RAA velocity-SR vs. AF: 46 ± 20 vs. 19 ± 8 m/sec (p < 0.01)]. Based on simple linear regression analysis, LAA velocity and RAA velocity were positively correlated, and RAA velocity was inversely correlated with brain natriuretic peptide (BNP).

Conclusion

AF was associated with decreased RAA and LAA flow velocities. RAA velocity was found to be positively correlated with LAA velocity and negatively correlated with BNP. The plasma BNP concentration may serve as a determinant of LAA and RAA functions.

Percutaneous treatment of patients with heart diseases: selection, guidance and follow-up. A review

Aortic stenosis and mitral regurgitation, patent foramen ovale, interatrial septal defect, atrial fibrillation and perivalvular leak, are now amenable to percutaneous treatment. These percutaneous procedures require the use of Transthoracic (TTE), Transesophageal (TEE) and/or Intracardiac echocardiography (ICE). This paper provides an overview of the different percutaneous interventions, trying to provide a systematic and comprehensive approach for selection, guidance and follow-up of patients undergoing these procedures, illustrating the key role of 2D echocardiography.