Wang J, Chung Ann Choo D, Zhang X, Yang Q, Xian T, Lu D, Jiang S
Department of Cardiology, Sir Run Run Shaw Hospital, Hangzhou, China.
Clin Cardiol. 2000 Jul;23(7):501-6. doi: 10.1002/clc.4960230708.
Spontaneous echo contrast (SEC) is a phenomenon that is commonly seen in areas of blood stasis. It is a slowly moving, cloud-like swirling pattern of "smoke" or increased echogenicity recorded on echocardiography. SEC is commonly seen in the left atrium of patients with mitral stenosis or atrial fibrillation. The presence of SEC has been shown to be a marker of increased thromboembolic risk.
By using transesophageal echocardiography during percutaneous balloon mitral valvotomy (PBMV), the study investigated the relationship between SEC and varying left atrial appendage (LAA) blood flow velocity in the human heart.
Thirty-five patients with rheumatic mitral stenosis underwent percutaneous balloon mitral valvotomy with intraoperative transesophageal echocardiography monitoring. We alternatively measured LAA velocities and observed the left atrium for various grades of SEC (0 = none to 4 = severe) before and after each balloon inflation.
Left atrial appendage maximal ejection velocity was reduced from 35 +/- 14 to 6 +/- 2 mm/s at peak balloon inflation and increased to 40 +/- 16 mm/s after balloon deflation. In comparison with the values before balloon inflation and after balloon deflation, LAA velocities were significantly lower (p < 0.001). New or increased SEC grade was observed during 54 of 61 (88%) inflations and unchanged in 7 (12%) inflations at peak balloon inflation. Spontaneous echo contrast became lower in grade after 55 balloon deflations (90%), completely disappeared after 18 deflations (30%), and remained unchanged after 6 deflations (10%). The mean time to achieve maximal SEC grade (2.5 +/- 1.2 s) coincided with the mean time to trough LAA velocities (2.3 +/- 1.1 s) after balloon inflation. Upon deflation, the mean time to lowest SEC grade (2.9 +/- 1.8 s) coincided with mean time to achieve maximal LAA velocities (2.7 +/- 1.6 s).
During balloon inflation, the severity of SEC was enhanced with corresponding reduction in LAA flow velocity. Upon balloon deflation, SEC lightens or disappears with increase in LAA flow velocity.
自发显影对比（SEC）是一种常见于血液淤滞区域的现象。它是一种在超声心动图上记录到的缓慢移动、云状的“烟雾”样或回声增强的漩涡模式。SEC常见于二尖瓣狭窄或心房颤动患者的左心房。已证明SEC的存在是血栓栓塞风险增加的一个标志物。
通过在经皮球囊二尖瓣成形术（PBMV）期间使用经食管超声心动图，该研究调查了人心脏中SEC与不同左心耳（LAA）血流速度之间的关系。
35例风湿性二尖瓣狭窄患者接受了术中经食管超声心动图监测下的经皮球囊二尖瓣成形术。在每次球囊充盈前后，我们交替测量LAA速度并观察左心房不同程度的SEC（0 = 无至4 = 重度）。
球囊充盈峰值时，左心耳最大射血速度从35±14降至6±2 mm/s，球囊放气后增加至40±16 mm/s。与球囊充盈前和放气后的数值相比，LAA速度显著降低（p < 0.001）。在61次充盈中的54次（88%）观察到新的或增加的SEC等级，7次（12%）在球囊充盈峰值时保持不变。55次球囊放气后（90%）自发显影对比等级降低，18次放气后（30%）完全消失，6次放气后（10%）保持不变。达到最大SEC等级的平均时间（2.5±1.2秒）与球囊充盈后LAA速度降至最低点的平均时间（2.3±1.1秒）一致。放气时，达到最低SEC等级的平均时间（2.9±1.8秒）与达到最大LAA速度的平均时间（2.7±1.6秒）一致。
在球囊充盈期间，SEC的严重程度随着LAA流速相应降低而增强。球囊放气时，随着LAA流速增加，SEC减轻或消失。
