The Value of Contrast-Enhanced Transesophageal Echocardiography in the Detection of Cardiac Right-to-Left Shunt Related with Cryptogenic Stroke and Migraine

Abstract

Purpose. To analyze the characteristics of right-to-left shunt (RLS) in patients with cryptogenic stroke and migraine by contrast-enhanced transesophageal echocardiography (c-TEE). Methods. The study population consisted of 330 patients with cryptogenic stroke and 330 patients with migraine who suspected PFO. All of them received c-TEE examination successfully. In terms of c-TEE analyses, RLS could be diagnosed when microbubbles were visualized in the transition from the right atrium to the left atrium. For semiquantitative analysis, a small amount of RLS was grade 1, indicating 1-10 microvesicles per frame could be seen in the left atrium, a moderate amount of RLS was grade 2, indicating 11-30 microvesicles per frame could be seen in the left atrium, and a large amount of RLS was grade 3, indicating more than 30 microvesicles per frame, or the left atrium is filled with microvesicles. Results. A total of 660 patients were analyzed in the study. PFO-RLS was detected in 348 (348/660, 52.7%) cases by TEE, while in 392 (392/660, 59.3%) cases by c-TEE. Simultaneously, P-RLS was detected in 239 (239/660, 36.2%) cases by c-TEE. Among 330 patients with cryptogenic stroke, PFO-RLS was detected in 198 cases; according to the c-TTE method (198/330, 60.0%), concurrently, 83 participants suffered from PFO-RLS and P-RSL (83/330, 25.1%), including 1 case with PFO and pulmonary arteriovenous fistula. Among 330 patients with migraine, PFO-RLS was detected in 194 cases; according to the c-TTE method (194/330, 58.7%), specifically, 90 participants suffered from PFO-RLS and P-RSL (90/330, 27.2%). There was no statistical significance between the two groups. P-RLS singly was detected in 28 cases with cryptogenic stroke, while in 38 cases with migraine, excluding from pulmonary arteriovenous fistula by CTA examination. In addition, semiquantitative results on c-TTE grading of RLS were compared between the two groups: grade 1 RLS in the migraine group (144/322) was significantly higher than that in the cryptogenic stroke group (71/309) ( P < 0.05 ). Grade 3 RLS in the cryptogenic stroke group (113/309) was significantly higher than that in the migraine group (67/322) ( P < 0.05 ). For grade 2 RLS, there was no statistical difference between the two groups ( P = 0.12 ). Conclusions. c-TEE can increase the positive rate of PFO diagnosis compared with TEE color Doppler. There is no significant difference in the incidence of PFO-PLS and P-RLS between the cryptogenic stroke group and the migraine group. The grades 2-3 RLS are mainly detected in the cryptogenic stroke group, while grades 1-2 RLS are mostly detected in the migraine group.

Applicability of Transthoracic Contrast Echocardiography for the Diagnosis and Treatment of Idiopathic Pulmonary Arteriovenous Malformations

“…PFO is widely known to be the most common cause of an intracardiac RLS. Other types of RLS, other than PFO-RLS, mainly originate from the lungs and are called pulmonary RLS (P-RLS), with the incidence rate between 20 and 41% ( 9 ). The main cause of pulmonary RLS at the pulmonary level is PAVMs.…”

“…Following the directions of the echocardiographers, saline contrast was administered through an antecubital vein by bolus injection while evaluating the four-chamber apical view. The evaluation method was as follows ( 9 , 10 ): the potential appearance of microbubbles, its timing, and its hunt origin were permitted to be intuitively observed. The presence of microbubbles derived from the pulmonary veins was classified as a pulmonary RLS ( Figure 2 ).…”

A Nomogram for the Prediction of Causative Patent Foramen Ovale in Cryptogenic Stroke

“…The large RLS meant that the appearance of ≥30 microbubbles in the left heart on one still frame following effective Valsalva maneuver on cTTE. [13] Echocardiography was performed to obtain cardiac structural and functional parameters. All patients were examined at sinus rhythm in the left lateral decubitus position.…”