关键词: 肺动静脉瘘; 卵圆孔未闭; 隐源性卒中; 经颅多普勒

Abstract:

Objective To explore the significance of contrast transcranial Doppler (cTCD) combined with transesophageal echocardiography (TEE) in the differential diagnosis of cryptogenic stroke with pulmonary arteriovenous fistula and patent foramen ovale. Methods Detailed clinical information were collected. TEE and cTCD were performed in 4 patients with cryptogenic stroke (2 patients with pulmonary arteriovenous fistula [PAVF] and 2 patients with patent foramen ovale [PFO]) to compare the difference in test results. Results cTCD in 2 patients with PAVF showed the following characteristics: detection of massive microembolic signals (curtain pattern) during regular breathing, and not influenced by Valsalva maneuver (VM). TEE showed large number of microbubbles appeared in the left atrium at 5th cardiac cycle after VM. cTCD in 2 patients with PFO showed: detection of none or 4 signals during regular breathing, and curtain pattern of signals after VM. TEE with color Doppler imaging showed left-to right shunt and several microbubbles appeared in the left atrium at 2nd-3rd cardiac cycle after VM. Conclusion cTCD combined with TEE is useful for differential diagnosis of PFO and PAVF due to high sensitivity and easy operation. The main identification points is that whether there are lots of massive microembolic signals and whether it will be influenced by VM at cTCD during regular breathing.

Key words: Pulmonary arteriovenous fistula; Patent foramen ovale; Cryptogenic stroke;
Transcranial Doppler