ABSTRACT
Objective: Pulmonary right-to-left shunt (P-RLS) and patent foramen ovale right-to-left shunt (PFO-RLS) often appear in combination, and there are often differences and connections between them. Intrapulmonary arteriovenous anastomoses (IPAVAs), as part of P-RLS, are often overlooked because there are no technologies to detect and identify them. This study aimed to further clarify the incidence and characteristics of P-RLS with the help of contrast transesophageal echocardiography (c-TEE) and contrast transthoracic echocardiography (c-TTE), providing a reference for clinically relevant research and patent foramen ovale (PFO) management disposal decisions. Methods: We retrospectively investigated 414 subjects who came to our hospital for c-TEE from October 2021 to July 2022, and all subjects completed c-TTE simultaneously. 7 Patients who were newly diagnosed with an atrial septal defect were excluded. Eventually, 407 patients were included in this study. Among them, 157 patients with PFO (58 patients were treated with PFO closure subsequently) and 250 patients without PFO confirmed by c-TEE were finally enrolled. In the process, we observed and analysed the presence of P-RLS. Results: A total of 407 patients were included in the final analysis and divided into PFO group (N = 157) and non-PFO group (N = 250) according to the results of c-TEE. Whether at rest or after Valsalva maneuver, the incidence of P-RLS was significantly higher under c-TEE than under c-TTE in the two groups (P < 0.001). For both c-TTE and c-TEE, the incidence of P-RLS was slightly higher after Valsalva maneuver than at rest, but the difference was not significant (c-TTE: rest vs. Valsalva maneuver, P = 0.214; c-TEE: rest vs. Valsalva maneuver, P = 0.076). The Valsalva maneuver increased the incidence of P-RLS in the group without PFO, which was more significant in c-TEE (c-TTE: rest vs. Valsalva maneuver, P = 0.591; c-TEE: rest vs. Valsalva maneuver, P = 0.008). In both groups, the P-RLS semiquantitative grading was statistical significance under different states and examinations (P < 0.001). Conclusion: The vast majority of P-RLS are grade 1-2 and are derived from physiological IPAVAs. Even so, attention should be given to the differentiation between P-RLS and PFO-RLS. c-TEE is an effective method to detect P-RLS; however, the recruitments of c-TEE and Valsalva maneuver to P-RLS should be noted.
ABSTRACT
BACKGROUND The purpose of the study was to investigate the ability of microbubbles (MBs) targeting interleukin-18 (IL-18) to detect plaques in a rabbit atherosclerotic plaque model. MATERIAL AND METHODS A rabbit atherosclerotic plaque model was established. The locations of the atherosclerotic plaques were verified by two-dimensional scanning and color Doppler flow imaging. An IL-18 antibody was conjugated to naked MBs (MBc) using the biotin-streptavidin conjugation method, resulting in the formation of MBIL-18. MBc and MBIL-18 were then used for contrast-enhanced ultrasound (CEUS) studies. The locations of CD34 and IL-18 within the plaques were determined by immunohistochemistry, and IL-18 expression levels in the plaques were determined by Western blot analysis. The relationships between IL-18 expression and the contrast intensity of the 2 MBs were analyzed. RESULTS MBc and MBIL-18 were both uniformly dispersed. Fluorescence microscopy and flow cytometry revealed that IL-18 was successfully conjugated to MBs. CEUS images showed that the intensity of the MBIL-18 signal was substantially enhanced and prolonged compared with that of the MBc signal. Immunohistochemistry showed that CD34 expression was significantly increased in the plaques and that IL-18 was mainly located in the inner parts and base of the atherosclerotic plaques. Western blot analysis revealed that IL-18 expression was higher in the plaque regions. Correlation analysis showed that IL-18 expression was correlated with the contrast intensity of MBIL-18 (r=0.903, P<0.05) but not with MBc (r=0.540, P>0.05). CONCLUSIONS MBs targeting IL-18 may be a novel, noninvasive method of diagnosing atherosclerotic plaques.