Data_Sheet_1_Preoperative Left Ventricular Energy Loss in the Operating Theater Reflects Subjective Symptoms in Chronic Aortic Regurgitation.doc

BackgroundThere is currently no subjective, definitive evaluation method for therapeutic indication other than symptoms in aortic regurgitation. Energy loss, a novel parameter of cardiac workload, can be visualized and quantified using echocardiography vector flow mapping. The purpose of the present study was to evaluate whether energy loss in patients with chronic aortic regurgitation can quantify their subjective symptoms more clearly than other conventional metrics.
MethodsWe studied 15 patients undergoing elective aortic valve surgery for aortic regurgitation. We divided the patients into symptomatic and asymptomatic groups using their admission records. We analyzed the mean energy loss in one cardiac cycle using transesophageal echocardiography during the preoperative period. The relationships between symptoms, energy loss, and other conventional metrics were statistically analyzed.
ResultsThere were seven and eight patients in the symptomatic and asymptomatic groups, respectively. The mean energy loss of one cardiac cycle was higher in the symptomatic group (121 mW/m [96–184]) than in the asymptomatic group (87 mW/m [80–103]) (p = 0.040), whereas the diastolic diameter was higher in the asymptomatic group (65 mm [59–78]) than in the symptomatic group (57 mm [51–57]) (p = 0.040). There was no significant difference between the symptomatic and asymptomatic groups in terms of other conventional metrics.
ConclusionsAn energy loss can quantify patients' subjective symptoms more clearly than other conventional metrics. The small sample size is the primary limitation of our study, further studies assessing larger cohort of patients are warranted to validate our findings.

背景：目前针对主动脉瓣关闭不全，除症状外尚无主观且明确的治疗指征评估方法。能量损失是一项新兴的心脏做功参数，可通过超声心动图矢量血流成像（echocardiography vector flow mapping）实现可视化与量化。本研究旨在评估慢性主动脉瓣关闭不全患者的能量损失是否较其他常规指标更能清晰量化其主观症状。
方法：本研究纳入15名因主动脉瓣关闭不全接受择期主动脉瓣手术的患者。根据入院记录将患者分为有症状组与无症状组。于术前经食管超声心动图（transesophageal echocardiography）分析单个心动周期的平均能量损失。对症状、能量损失及其他常规指标之间的相关性进行统计学分析。
结果：有症状组与无症状组患者分别为7例和8例。有症状组单个心动周期的平均能量损失[121 mW/m（96~184）]高于无症状组[87 mW/m（80~103）]（p=0.040）；而无症状组的舒张期直径[65 mm（59~78）]高于有症状组[57 mm（51~57）]（p=0.040）。其他常规指标在两组间均无显著差异。
结论：能量损失较其他常规指标更能清晰量化患者的主观症状。本研究的主要局限性为样本量较小，未来需开展更大规模队列研究以验证本研究结果。