Optimized transcranial Doppler technique for the diagnosis of cardiac right-to-left shunts.
Transcranial Doppler sonography (TCD) is a simple method to detect a right-to-left cardiac shunt, although standardized procedures do not exist. In this study 69 patients were tested according to predetermined criteria and procedures (cluster of > 10 microbubbles, duration between injection in the cubital vein and detection in the middle cerebral artery [MCA] < or = 10 sec). Agitated saline solution was compared to oxypolygelatine, a plasma volume expander, as contrast media. Valsalva's maneuver and coughing were used to provoke right-to-left cardiac shunting, detected by TCD, transthoracic echocardiography (TTE), and transesophageal echocardiography (TEE). Oxypolygelatine caused a significantly higher number of microbubbles in the right atrium and MCA than did the saline solution, leading to a greater diagnostic reliability of TCD (paired t test, p < 0.001). Coughing did not provoke right-to-left cardiac shunts (x2 analysis, p < 0.001). The technique used for carrying out Valsalva's maneuver was important for the detection of right-to-left cardiac shunts. Twenty-five right-to-left shunts were diagnosed with TCD and 18 with TTE (36 vs 26%; x2 analysis, p = 0.1). The findings indicate that TCD when properly done is highly sensitive and specific for the diagnosis of right-to-left cardiac shunts.
Albert
A
A
Department of Neurology, University of Freiburg, Germany.
Müller
H R
HR
Hetzel
A
A
D000328:Adult; D002545:Brain Ischemia / Q000209:etiology; D003287:Contrast Media; D003371:Cough; D004452:Echocardiography / Q000379:methods; D017548:Echocardiography, Transesophageal; D019320:Embolism, Paradoxical / Q000209:etiology; D005260:Female; D005780:Gelatin / Q000031:analogs & derivatives; D006344:Heart Septal Defects, Atrial / Q000150:complications / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D010952:Plasma Substitutes; D012965:Sodium Chloride; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*; D014636:Valsalva Maneuver
D003287:Contrast Media; D010952:Plasma Substitutes; D012965:Sodium Chloride; D005780:Gelatin; C002803:oxypolygelatine