Cardioneurovascular Department, Grosseto Hospital, Azienda USL Toscana Sudest.
Centro Cardiologico Monzino IRCCS, Milano, Milano, Italy.
J Cardiovasc Med (Hagerstown). 2019 Oct;20(10):660-666. doi: 10.2459/JCM.0000000000000838.
Blood stasis is the main cause of left atrial thrombosis (LAT) in atrial tachyarrhythmias. The high-velocity flow inside the left atrium, due to mitral valve regurgitation, may prevent clot formation but the topic has never been investigated in large-scale studies. The aim of our study was to evaluate whether the presence and degree of mitral regurgitation have a protective role against LAT risk.
A total of 1302 consecutive adult patients with paroxysmal or persistent atrial fibrillation or flutter undergoing cardioversion, submitted to transesophageal echocardiography, were retrospectively enrolled in the study. The study population was divided into three groups according to the mitral regurgitation degree: absent, mild-to-moderate and severe.
Among 1302 patients enrolled in the study, patients without mitral regurgitation were 248 (19%), those with mild-to-moderate 970 (75%), whereas 84 had severe mitral regurgitation (6%). LAT incidence was significantly lower in patients with severe mitral regurgitation compared with those with mild-to-moderate (mitral regurgitation) (2.4 vs. 8.9%, P < 0.05), and similar to subjects without mitral regurgitation (2.4%).
Despite patients with severe regurgitation having clinical and echo characteristics predisposing to LAT (higher age, heart failure, higher atrial size, lower ventricular function) thrombosis prevalence was significantly lower than for those with mild-to-moderate mitral regurgitation. The percentage of LAT in severe mitral regurgitation cases was very low and similar to that of cases without regurgitation which were characterized by lower age, normal left ventricular function or other risk factors, reinforcing the hypothesis of a protecting role against atrial thrombosis of mitral regurgitation.
血瘀是房性心动过速中左心房血栓（LAT）的主要原因。由于二尖瓣反流，左心房内的高速血流可能会阻止血栓形成，但这个问题从未在大规模研究中进行过调查。本研究旨在评估二尖瓣反流的存在和程度是否对 LAT 风险具有保护作用。
回顾性纳入 1302 例接受电复律的阵发性或持续性心房颤动或扑动的成年患者，所有患者均接受经食管超声心动图检查。根据二尖瓣反流程度将研究人群分为三组：无、轻度至中度和重度。
在纳入的 1302 例患者中，无二尖瓣反流的患者为 248 例（19%），轻度至中度反流的患者为 970 例（75%），而重度反流的患者为 84 例（6%）。与轻度至中度二尖瓣反流（反流）的患者相比，重度二尖瓣反流患者的 LAT 发生率明显较低（2.4% vs. 8.9%，P<0.05），与无二尖瓣反流的患者相似（2.4%）。
尽管重度反流患者具有易发生 LAT 的临床和超声心动图特征（年龄较大、心力衰竭、心房增大、心室功能较低），但血栓形成的发生率明显低于轻度至中度二尖瓣反流患者。重度二尖瓣反流患者的 LAT 发生率非常低，与无反流患者相似，后者的特征是年龄较低、左心室功能正常或其他危险因素，这进一步支持了二尖瓣反流对心房血栓形成具有保护作用的假说。
