风湿性心脏病二尖瓣狭窄患者左房血栓形成的多因素回归分析

Multilogistic analysis on left atrial thrombosis in patients with rheumatic mitral stenosis

目的 :探讨风湿性心脏病二尖瓣狭窄 (风心二狭 )患者左房血栓形成的临床相关因素。方法 :6 9例风心二狭患者行经胸及食管超声心动图检查 ,并用发色底物显色法测定血浆组织型纤溶酶原激活物 (t PA )、组织型纤溶酶原激活物抑制物 1(PAI- 1)及抗凝血酶 (AT- )活性。结果 :33例风心二狭左房血栓形成组与 36例无血栓组比较 ,年龄偏大 ,症状持续时间较长 ,心房颤动发生率高 ;超声心动图显示左房内径较大 ,左室射血分数较低 ,二尖瓣口面积较小 ,明显二尖瓣关闭不全少见 ,左房自发性回声 (SEC)发生率明显增高 ;血液学检查显示红细胞压积较高 ,AT- 活性较低 t PA活性较高 ,PAI- 1活性较低。多元回归分析表明左房 SEC、AT- 活性、年龄、二尖瓣口面积大小是左房血栓形成的独立相关因素。结论 :风心二狭患者左房血栓的形成不仅与血流的局部机械性梗阻淤滞 ,而且与机体抗栓能力的下降有关。

Objective:To determine the risk factors of left atrial (LA) thrombosis in patients with predominant mitral stenosis based on clinical characteristics,echocardiogaphic findings and coagulation studies.Method:Transthoracic and transesophageal echocardiography were performed in 69 patients with predominant rheumatic mitral stenosis.Serum tissue type plasminogen (t PA) activity,plasminogen activator inhibitor 1(PAI 1) activity and antithrombin Ⅲ (AT Ⅲ) activity were measured by the chromogenic substrate method.Result:Of 69 patients,33 patients (group Ⅰ) had LA thrombus and 36 patients (group Ⅱ) had no LA thrombus.Univariate analysis revealed that patients in group Ⅰ had older age,longer duration of symptoms and higher incidence of atrial fibrillation than those in group Ⅱ.Echocardiographic studies showed that patients with LA thrombus had a larger LA diameter,lower left ventricular ejection fraction (EF),a smaller mitral valve orifice and a lower incidence of significant MR.Patients in group Ⅰ had LA spontaneous echo contrast.The incidence of LA spontaneous echo contrast in group Ⅰ was significantly higher than that in group Ⅱ.Blood coagulation studies revealed that patients in group Ⅰ had a higher hematocrit,lower antithrombin Ⅲ,lower PAI 1 activity and higher tPA activity (P< 0.05 ).Logistic regression analysis revealed that presence of LA spontaneous echo contrast,decreased antithrombin Ⅲ activity,older age,smaller mitral valve area were the independent risk factors for LA thrombosis.Conclusion:LA thrombosis in predominant mitral stenosis is related not only to mechanical obstruction,but also to decreased antithrombogenic factors.