練合 泰明, 吉田 茂夫, 伊東 佳澄, 福田 守道

Yasuaki NERIAI, Shigeo YOSHIDA, Kasumi ITO, Morimichi FUKUDA

札幌医科大学機器診断部

Department of Ultrasound and Medical Electronics, Sapporo Medical University

キーワード : Patent foramen ovale, Contrast-Valsalva maneuver transesophageal echocardiography, Valsalva maneuver, Continuous digital arterial pressure monitoring, Transient spontaneous contrast ceho

The relationship between paradoxical embolization and patent foramen ovale (PFO) is well known. However, few studies on the accuracy of its diagnosis have been conducted. In recent times, transesophageal echocardiography has been found to be superior to transthoracic echocardiography in detecting a PFO. Accurate diagnosis of paradoxical embolism via PFO is quite difficult, because the right-to-left shunt through PFO seldom occurs under normal hemodyonamic conditions. In this study, we assessed the usefulness and the problems of using contrast-Valsalva maneuver transesophageal echocardiography (C-V TEE) to detect right-to-left shunt via PFO through the examination of 68 patients. A PFO was diagnosed from the following TEE findings: 1) Two separate interatrial septa were detected, but there was no obvious IAS structure defect. 2) Left-to-right shunting at the atrial level was detected by Doppler color flow mapping, and/or the negative jet phenomenon was detected by rightatrial contrast TEE. PFO was diagnosed in 16 of the 68 patients (23.5%) in our study. No case displayed a right-to-left shunt at rest. Right-to-left shunts were detected in 6 of 16 patients (37.5%) by C-V TEE, and 2 of 16 patients (12.5%) by Doppler color flow mapping after the employment of the Valsalva maneuver. These two cases were also diagnosed by C-V TEE. Continuous digital arterial pressure monitoring and interatrial septal motion recording were necessary for the accurate evaluation of C-V TEE. Transient spontaneous contrast echo (T-SCE) was detected in the left atrium after the employment of the Valsalva maneuver in 15 of the 68 patients (22%). T-SCE was mistakably diagnosed as the cause of the right-to-left shunt by C-V TEE. In order to avoid such mistaken diagnoses, we have to test for T-SCE in the left atrium by the Valsalva maneuver before the injection of a contrast medium. From these results, it is clear that contrast-Valsalva maneuver transesophageal echocardiography with continuous arterial pressure monitoring is a useful method for diagnosing paradoxical embolism via PFO.