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Abstract：
Rest and stress echocardiography (SE) play a fundamental role in the evaluation of aortic valve stenosis (AS). According to the current guidelines for the echocardiographic evaluation of patients with aortic stenosis, four broad categories can be defined: high-gradient AS (mean gradient ≥ 40 mmHg, peak velocity ≥ 4 m/s, aortic valve area (AVA) ≤ 1 cm2 or indexed AVA ≤ 0.6 cm2/m2); low-flow, low-gradient AS with reduced ejection fraction (mean gradient < 40 mmHg, AVA ≤ 1 cm2, left ventricle ejection fraction (LVEF) < 50%, stroke volume index (Svi) ≤ 35 mL/m2); low-flow, low-gradient AS with preserved ejection fraction (mean gradient < 40 mmHg, AVA ≤ 1 cm2, LVEF ≥ 50%, SVi ≤ 35 mL/m2); and normal-flow, low-gradient AS with preserved ejection fraction (mean gradient < 40 mmHg, AVA ≤ 1 cm2, indexed AVA ≤ 0.6 cm2/m2, LVEF ≥ 50%, SVi > 35 mL/m2). Aortic valve replacement (AVR) is indicated with the onset of symptoms development or LVEF reduction. However, there is often mismatch between resting transthoracic echocardiography findings and patient\'s symptoms. In these discordant cases, SE and CT calcium scoring are among the indicated methods to guide the management decision making. Additionally, due to the increasing evidence that in asymptomatic severe aortic stenosis an early AVR instead of conservative treatment is associated with better outcomes, SE can help identify those that would benefit from an early AVR by revealing markers of poor prognosis. Low-flow, low-gradient AS represents a challenge both in diagnosis and in therapeutic management. Low-dose dobutamine SE is the recommended method to distinguish true-severe from pseudo-severe stenosis and assess the existence of flow (contractile) reserve to appropriately guide the need for intervention in these patients.
摘要：
静息和应力超声心动图（SE）在评估主动脉瓣狭窄（AS）中起着重要作用。根据目前主动脉瓣狭窄患者超声心动图评价指南,可以定义四大类：高梯度AS(平均梯度≥40mmHg，峰值速度≥4m/s,主动脉瓣面积（AVA）≤1cm2或指数AVA≤0.6cm2/m2）；低流量，射血分数降低的低梯度AS（平均梯度<40mmHg，AVA≤1cm2,左心室射血分数(LVEF)<50%,每搏量指数（Svi）≤35mL/m2）；低流量，射血分数保持的低梯度AS(平均梯度<40mmHg，AVA≤1cm2,LVEF≥50%,SVi≤35mL/m2)；和正常流量，射血分数保持的低梯度AS(平均梯度<40mmHg，AVA≤1cm2,指数AVA≤0.6cm2/m2,LVEF≥50%,SVi>35mL/m2)。主动脉瓣置换术（AVR）表明症状发展或LVEF降低。然而,静息经胸超声心动图检查结果与患者症状常不匹配。在这些不和谐的情况下，SE和CT钙评分是指导管理决策的指定方法之一。此外,由于越来越多的证据表明，在无症状的严重主动脉瓣狭窄中，早期AVR而不是保守治疗与更好的结果相关，SE可以通过揭示预后不良的标志物来帮助识别将从早期AVR中受益的那些。低流量,低梯度AS在诊断和治疗管理方面都是一个挑战.低剂量多巴酚丁胺SE是区分真重度和假性重度狭窄并评估流量（收缩）储备的存在的推荐方法，以适当指导这些患者的干预需求。
