Does Left Atrial Appendage Morphology Influence Left Atrial Appendage Flow Velocity?

Abstract

Background:The shape of the left atrial appendage (LAA) might affect thrombus formation. The chicken wing-type LAA (CW) has been reported as unlikely to influence stroke events in atrial fibrillation (AF) patients, so we investigated whether LAA shapes could influence LAA function. Methods and Results:We studied 102 patients (64 men, age 65±9 years) who underwent transthoracic echocardiography, transesophageal echocardiography (TEE), and cardiac computed tomography prior to catheter ablation (CA) for AF. LAA morphology were classified into 2 types: (1) CW: LAA with a bend in its shape and (2) non-CW type (NCW): LAA without any bends. All patients were classified into these groups using a cutoff value of LAA flow velocity (LAAFV). Patients with LAAFV <35 cm/s were classified as the low LAAFV group (Low FV, n=37). The patients with LAAFV >35 cm/s were classified as normal LAAFV group (Normal FV, n=65). The NCW type was detected in 25/102 patients (25%). In multivariate analysis, the patients with Low FV were associated with NCW type (P=0.0429, odds ratio [OR] 9.664, 95% confidence interval [CI] 1.075-86.900) and higher B-type natriuretic peptide (BNP) (P=0.0350, OR 1.012 for each 1 pg/ml increase in BNP, 95% CI 1.001-1.022). Conclusions:The NCW-type LAA and higher BNP were associated with lower LAAFV. One reason for the frequent cardiogenic stroke in patients with the NCW-type LAA may be the lower LAAFV. (Circ J 2015; 79: 1706 -1711

Left Atrial Appendage Function and Stroke Risk

“…48 Furthermore, cauliflower LAA morphology was an independent predictor of stroke which is possibly related to extensive LAA trabeculations. 49 LAA flow velocity was highest among patients with chicken-wing as opposed to non-chicken wing morphology 29, 51, 52 which may explain why chicken wing morphology has the lowest risk of ischemic stroke. In addition, larger LAA orifice area has also been shown to be associated with ischemic stroke (Table).…”

Atrial cardiopathy: a mechanism of cryptogenic stroke

“…31 Furthermore, cauliflower LAA morphology was an independent predictor of stroke risk, presumably related to extensive LAA trabeculations. 32 LAA flow velocity, another inverse marker of stroke risk, was highest among patients with chicken-wing as opposed to non-chicken wing morphology, 28, 33, 34 which may also explain why chicken wing morphology has the lowest risk of ischemic stroke. In addition, larger LAA orifice area has also been shown to be associated with ischemic stroke.…”

The Mechanism of and Preventive Therapy for Stroke in Patients with Atrial Fibrillation

“…The findings from previous studies have shown that the non-chicken wing types are associated with a greater risk of stroke than the chicken wing type, and that the highest risk is associated with the cauliflower type, even in patients with low CHADS 2 scores. However, the findings from other investigations have not demonstrated a relationship between these specific morphologies and the stroke risk [ 36 - 39 ]. A greater LAA complexity, including more extensive trabeculation and multiple lobes, has been associated with an increased stroke risk, but further studies are warranted to confirm these results.…”