ABSTRACT
BACKGROUND: Left atrial (LA) strain as a marker for discrimination of risk for stroke and transient ischemic attack (TIA) in patients with atrial fibrillation and low-risk CHADS(2) scores (≤1) has yet to be examined. METHODS: Patients with atrial fibrillation, stroke or TIA, and CHADS(2) scores ≤ 1 before their events were identified retrospectively from a large single-center stroke registry and compared with age-matched and gender-matched controls. Antihypertensive use and echocardiographic parameters including chamber volumes and left ventricular mass and LA peak negative and positive strain and strain rate were compared between groups. RESULTS: Fifty-seven patients meeting entry criteria were identified. Patients demonstrated significantly lower left ventricular ejection fractions, larger LA dimensions, and larger LA volume indexes (24.4 ± 11.9 vs 32.3 ± 13.3 mL/m(2), P = .012) compared with controls. Both peak negative LA strain (-3.2 ± 1.2% vs -6.9 ± 4.2%, P < .001) and peak positive LA strain (14 ± 11% vs 25 ± 12%, P < .001) were significantly reduced in patients compared with controls. Peak negative LA strain was significantly associated with stroke by binary logistic regression (odds ratio, 2.15; P < .001). CONCLUSIONS: In patients with low-risk CHADS(2) scores, atrial fibrillation, and stroke or TIA, reduced LA strain is a potentially sensitive maker for increased risk for stroke or TIA. These results suggest that LA strain may have potential as a tool for helping guide the decision for or against oral anticoagulation in this group of patients.
Subject(s)
Atrial Fibrillation/diagnostic imaging , Atrial Fibrillation/epidemiology , Heart Atria/diagnostic imaging , Ischemic Attack, Transient/diagnostic imaging , Ischemic Attack, Transient/epidemiology , Stroke/diagnostic imaging , Stroke/epidemiology , Aged , Atrial Fibrillation/physiopathology , Comorbidity , Connecticut/epidemiology , Elastic Modulus , Elasticity Imaging Techniques/statistics & numerical data , Female , Heart Atria/physiopathology , Humans , Incidence , Ischemic Attack, Transient/physiopathology , Male , Registries , Reproducibility of Results , Risk Factors , Sensitivity and Specificity , Stroke/physiopathologyABSTRACT
Echocardiography plays a longstanding and vital role in the management of atrial fibrillation (AF). Advances in 2D imaging, Doppler echocardiography and strain imaging have all contributed to major progress in AF treatment. Echocardiographically measured left atrial (LA) volume is a powerful predictor of maintenance of sinus rhythm following cardioversion as well as risk of thrombus formation and thromboembolism. Doppler derived parameters of atrial mechanical function including atrial ejection force provide related prognostic information. Transesophageal echocardiocardiograpy (TEE) guided cardioversion of AF allows for rapid conversion to sinus rhythm without prolonged oral anticoagulation, and TEE serves as a useful tool during catheter ablation of AF and atrial flutter. Newer measures derived from speckle tracking offer great promise in further improving the care of patients with AF.
ABSTRACT
BACKGROUND: Although transesophageal echocardiography is the definitive test for the detection of left atrial (LA) appendage thrombus, transthoracic echocardiography has yet to prove useful for the determination of increased risk for LA appendage thrombus formation. The authors hypothesized that higher LA volume and/or lower left ventricular ejection fraction (LVEF) might prove valuable as markers of increased risk for LA appendage thrombus formation and tested this hypothesis in a consecutive retrospective series of patients with atrial fibrillation undergoing both transthoracic and transesophageal echocardiography. METHODS: Three hundred thirty-four consecutive patients with atrial fibrillation undergoing transesophageal echocardiography for the detection of LA appendage thrombus were studied. Anticoagulation status, CHADS(2) scores, and echocardiographic parameters were catalogued. The relationship between the presence of LA appendage thrombus and covariates was analyzed using binary logistic regression. RESULTS: LA appendage thrombus was detected in 52 patients (15.6%). A higher CHADS(2) score (odds ratio, 1.45; P < .004), increased LA volume index (odds ratio, 1.02; P = .018), and lower LVEF (odds ratio, 1.02; P = .05) were significant predictors of LA appendage thrombus formation. LA appendage thrombus was not seen in patients with CHADS(2) scores ≤ 1, LVEFs > 55%, and a LA volume indexes < 28 mL/m(2). A ratio of LVEF to LA volume index ≤ 1.5 produced 100% sensitivity for the presence of LA appendage thrombus. CONCLUSIONS: The presence of LA appendage thrombus is related to both clinical and echocardiographic variables. Although no single echocardiographic variable discriminated between the presence and absence of LA thrombus, a normal LVEF and normal LA volume index were associated with the absence of LA appendage thrombus formation. For patients with atrial fibrillation with CHADS(2) scores ≤ 1, normal left ventricular systolic function and normal LA volume in combination may be a useful measure for the identification of patients at low risk for LA appendage thrombus formation.
