Nemec J J, Marwick T H, Lorig R J, Davison M B, Chimowitz M I, Litowitz H, Salcedo E E
Department of Cardiology, Cleveland Clinic Foundation, Ohio.
Am J Cardiol. 1991 Dec 1;68(15):1498-502. doi: 10.1016/0002-9149(91)90285-s.
Transesophageal contrast echocardiography is an effective but semiinvasive technique for the detection of interatrial right-to-left shunts. Transcranial Doppler ultrasound is an alternative noninvasive method, but may be limited by false-positive diagnoses due to intrapulmonary shunting. This study examined the accuracy of transcranial Doppler for the detection of shunt lesions. Transcranial Doppler of the right middle cerebral artery was performed simultaneously with transesophageal and transthoracic contrast echocardiography in 32 patients using agitated saline contrast during normal respiration and Valsalva. Transesophageal contrast echocardiography diagnosed an interatrial right-to-left shunt in 13 patients and intrapulmonary shunting in 6 patients. Transcranial Doppler identified all 13 interatrial right-to-left shunts and an intrapulmonary shunt in 3 of 6 patients. Absence of a shunt was confirmed by transcranial Doppler in 12 of 12 patients. Transcranial Doppler had a sensitivity of 100% (13 of 13), specificity of 100% (18 of 18) and accuracy of 100% (31 of 31) for prediction of an interatrial right-to-left shunt by transesophageal contrast echocardiography. In comparison, transthoracic contrast echocardiography had a sensitivity of 54% (7 of 13), specificity of 94% (17 of 18) and accuracy of 77% (24 of 31). Thus, transcranial Doppler is highly accurate for detection of an interatrial right-to-left shunt and not compromised by physiologic intrapulmonary shunts, whereas transthoracic contrast echocardiography lacks sensitivity. Transcranial Doppler may be useful as an alternative to transesophageal study, where the primary indication for transesophageal echocardiography is exclusion of an interatrial right-to-left shunt.
经食管对比超声心动图是检测心房水平右向左分流的一种有效但半侵入性的技术。经颅多普勒超声是另一种非侵入性方法，但可能因肺内分流导致假阳性诊断而受到限制。本研究检测了经颅多普勒检测分流病变的准确性。在32例患者正常呼吸和瓦尔萨尔瓦动作时，使用搅拌生理盐水对比剂，同步进行经颅多普勒对右侧大脑中动脉的检测以及经食管和经胸对比超声心动图检查。经食管对比超声心动图诊断出13例患者存在心房水平右向左分流，6例患者存在肺内分流。经颅多普勒识别出所有13例心房水平右向左分流以及6例患者中的3例存在肺内分流。经颅多普勒证实12例患者中12例无分流。经颅多普勒预测经食管对比超声心动图检测心房水平右向左分流的敏感性为100%（13/13），特异性为100%（18/18），准确性为100%（31/31）。相比之下，经胸对比超声心动图的敏感性为54%（7/13），特异性为94%（17/18），准确性为77%（24/31）。因此，经颅多普勒检测心房水平右向左分流高度准确，且不受生理性肺内分流的影响，而经胸对比超声心动图缺乏敏感性。在经食管超声心动图的主要适应证是排除心房水平右向左分流的情况下，经颅多普勒可作为经食管检查的替代方法。
