Tsai L M, Chen J H, Lin L J, Teng J K
Department of Internal Medicine, National Cheng Kung University Medical College and Hospital, Tainan, Taiwan, Republic of China.
Am J Cardiol. 1997 Oct 1;80(7):897-900. doi: 10.1016/s0002-9149(97)00543-2.
A prospective study was designed to investigate potential changes of left atrial (LA) spontaneous echo contrast with time and the effects of antithrombotic therapy on its presence in 77 patients with chronic nonrheumatic atrial fibrillation (AF), using serial transesophageal echocardiography (TEE). During a mean follow-up period of 20 +/- 15 months (range 6 to 77), a total of 197 TEE studies were performed in these patients. Baseline TEE revealed that LA spontaneous echo contrast was absent in 43 patients (group 1) and present in 34 (group 2). LA thrombus was found in 8 of group 2 but in none of the group 1 patients. During the follow-up period, only 2 of the group 1 patients were receiving antithrombotic agents; the patients in group 2 without LA thrombus were treated with either warfarin or aspirin, whereas those with LA thrombus were treated with warfarin. On the latest TEE study, LA spontaneous echo contrast was observed in 19 of the group 1 patients (44%) and was persistently found in all of the group 2 patients. During the study period, no patient was found to develop new LA thrombus formation and only 4 episodes of transient ischemic attack were recorded in 4 patients (embolic event rate = 3.1% per year). Of these, 2 were observed in group 1 and the remaining 2 were from group 2 and under aspirin therapy (event rate = 2.2% and 4.7% per year, respectively). In the subgroup of patients with LA thrombus receiving warfarin therapy, follow-up TEE revealed complete resolution of the thrombi in 6 and partial resolution in the remaining 2 in spite of the persistence of LA spontaneous echo contrast; none of these patients developed clinical thromboembolic events during the study period. Thus, future occurrence of LA spontaneous echo contrast could be observed by serial TEE at a substantial rate in patients with nonrheumatic AF who have no LA spontaneous echo contrast; follow-up TEE should be recommended for these patients to detect early the potential occurrence of LA spontaneous echo contrast if preventive antithrombotic therapy is not considered. Although warfarin therapy is associated with resolution of LA thrombus, neither warfarin nor aspirin is effective for suppressing the presence of LA spontaneous echo contrast in nonrheumatic AF.
一项前瞻性研究旨在利用连续经食管超声心动图（TEE），调查77例慢性非风湿性心房颤动（AF）患者左心房（LA）自发显影随时间的潜在变化以及抗栓治疗对其存在情况的影响。在平均20±15个月（范围6至77个月）的随访期内，这些患者共进行了197次TEE检查。基线TEE显示，43例患者（第1组）无LA自发显影，34例患者（第2组）有LA自发显影。第2组中有8例发现LA血栓，而第1组患者均未发现。随访期间，第1组仅2例患者接受抗栓药物治疗；第2组中无LA血栓的患者接受华法林或阿司匹林治疗，而有LA血栓的患者接受华法林治疗。在最近一次TEE检查中，第1组19例患者（44%）观察到LA自发显影，第2组所有患者均持续存在LA自发显影。研究期间，未发现患者出现新的LA血栓形成，仅4例患者记录到4次短暂性脑缺血发作（栓塞事件发生率=每年3.1%）。其中，2例在第1组观察到，其余2例来自第2组且接受阿司匹林治疗（发生率分别为每年2.2%和4.7%）。在接受华法林治疗的LA血栓患者亚组中，随访TEE显示，6例血栓完全溶解，其余2例部分溶解，尽管LA自发显影持续存在；这些患者在研究期间均未发生临床血栓栓塞事件。因此，对于无LA自发显影的非风湿性AF患者，通过连续TEE可观察到相当比例的患者未来会出现LA自发显影；如果不考虑预防性抗栓治疗，建议对这些患者进行随访TEE，以早期发现LA自发显影的潜在发生情况。尽管华法林治疗可使LA血栓溶解，但华法林和阿司匹林均不能有效抑制非风湿性AF中LA自发显影的存在。
