The diagnostic efficiency of diffusion-weighted imaging in placenta accreta spectrum: a systematic review and meta-analysis.

OBJECTIVE: This study aims to evaluate the diagnostic efficiency of diffusion-weighted imaging (DWI) in patients with placenta accreta spectrum (PAS). MATERIALS AND METHODS: The present study searched on PubMed, Embase, OVID, Cochrane, Scopus and CNKI, Chinese Bio-Medical Literature, VIP, Wanfang, Duxiu, databases for studies related to the diagnostic performance of DWI for PAS from inception to December 2022. The pooled sensitivity, the pooled specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnosis odds ratios (DOR) were calculated by Meta-disc 1.4 and STATA 16.0. RESULTS: A total of 11 studies met the criteria and were included in the meta-analysis. The effect indexes of DWI in combined PAS were as follows. The pooled sensitivity was 0.670 (0.619-0.719). The pooled specificity was 0.720 (0.661-0.773). The pooled LR+ was 2.161 (1.454-3.211). The pooled LR- was 0.413 (0.280-0.609). The pooled AUC was 0.7841, and Q* was 0.7221. The pooled diagnostic ratio DOR was 6.713 (2.981-15.118). Subgroup analysis showed that four studies used T2-weighted imaging (T2WI) + DWI to diagnose PAS, and the pooled AUC was 0.9822. CONCLUSIONS: The results showed that DWI had high sensitivity and specificity in the diagnosis of PAS. Furthermore, T2WI+DWI has higher diagnostic efficacy than DWI alone in the diagnosis of PAS. Therefore, it is necessary to set T2WI+DWI as a routine sequence for PAS, and T2WI+DWI should be a routine method for the daily diagnosis of PAS.

[Risk factors of gastrointestinal polypectomy concurrent with bleeding in patients with liver cirrhosis].

Objective: To investigate and analyze the occurrence and the related risk factors of gastrointestinal polypectomy accompanied by bleeding in patients with liver cirrhosis. Methods: 127 cases of gastrointestinal polyps with cirrhosis who had endoscopy at the Endoscopic Center of Tianjin Third Central Hospital between November 2017 and November 2020 were collected. At the same time, 127 cases of gastrointestinal polyps with non-cirrhosis that were treated by endoscopy were collected for comparison. The occurrence of hemorrhagic complications between the two groups was compared. The effects of age, sex, liver function, peripheral blood leukocytes, hemoglobin, platelets, blood glucose, the international normalized ratio (INR), polyp resection method, polyp location, size, number, endoscopic morphology, pathology, the presence or absence of diabetes, portal vein thrombosis, and esophageal varices on polypectomy bleeding in the cirrhosis group were analyzed. The measurement data between groups were compared using the t-test and rank sum test. The χ (2) test or Fisher's exact probability method, and multivariate logistic regression analysis were used for the comparison of categorical data between groups. Results: The number of polypectomy bleeding cases in the cirrhotic group was 21, with a bleeding rate of 16.5%. The number of bleeding cases in the non-cirrhotic group was 3, with a bleeding rate of 2.4%. The bleeding rate was higher in the cirrhosis group when polypectomy was performed (χ (2) = 14.909, P < 0.001). A univariate analysis of the risk factors for gastrointestinal polypectomy associated with bleeding in patients with liver cirrhosis showed that liver function grading, platelets, INR, hemoglobin, degree of esophageal and gastric varices, and the location, shape, size, and pathology of the polyps had a statistically significant impact on bleeding (P < 0.05). Multivariate logistic regression analysis showed that liver function grade, degree of varicose veins, and polyp location were independent risk factors for bleeding. Patients with Child-Pugh B or C grade liver function were more likely to bleed than those with Child-Pugh A grade (OR = 4.102, 95% CI 1.133 ~ 14.856), gastric polyps were more likely to bleed than colorectal polyps (OR = 27.763, 95% CI 5.567 ~ 138.460), and severe esophagogastric varices were more likely to bleed than no varices or mild to moderate varices (OR = 7.183, 95% CI 1.384 ~ 37.275). Conclusion: Cirrhotic population has higher risk of bleeding during endoscopic gastrointestinal polypectomy than the non-cirrhotic population. Cirrhotic patients with Child-Pugh grades B or C liver function, polyps located in the stomach, severe esophagogastric varices, and other high-risk factors should be listed as a relative contraindication for endoscopic polypectomy.

[The success rate of His-Purkinje system pacing in patients with various sites of atrioventricular block].

Objective: To evaluate the success rate of His-Purkinje system pacing (HPSP) in patients with various sites of atrioventricular block (AVB) and provide clinical evidence for the selection of HPSP in patients with AVB. Methods: This is a retrospective case analysis. 637 patients with AVB who underwent permanent cardiac pacemaker implantation and requiring high proportion of ventricular pacing from March 2016 to September 2021 in the Department of Cardiology, General Hospital of Northern Theater Command were enrolled. The site of AVB was determined by electrophysiological examination. His bundle pacing (HBP) was performed in the first 130 patients (20.4%) who were classified as the HBP group and HPSP included HBP and/or left bundle branch pacing (LBBP) was performed in later 507 patients (79.6%) and these patients were classified as the HPSP group. The basic clinical information such as age and sex of the two groups was compared, and the success rates of HBP or HPSP in patients with different sites of AVB and QRS intervals were analyzed. Results: The age of HBP group was (66.4±15.9) years with 75 males (57.7%). The age of HPSP group was (66.8±13.6) years with 288 (56.8%) males. Among 637 patients, 63.0% (401/637) had atrioventricular node block; 22.9% (146/637) had intra-His block; 14.1% (90/637) had distal or inferior His bundle block. Totally, the success rate of HPSP was higher than that of HBP [93.9% (476/507) vs. 86.9% (113/130), P<0.05]. In each group of patients with various AVB sites, the success rate of HPSP was higher than that of HBP respectively and both success rates of HBP and HPSP showed a declining trend with the distant AVB site. The success rate of HBP in patients with atrioventricular node block and intra-His block was higher than that in patients with distal or inferior His bundle block [95.2% (79/83) vs. 47.1% (8/17), P<0.001; 86.7% (26/30) vs. 47.1% (8/17), P=0.010]. The success rate of HPSP was higher than that of HBP in patients with distal or inferior His bundle block [87.7% (64/73) vs 47.1% (8/17), P=0.001]. In patients with QRS<120 ms, 94.9% (520/548) of AVB sites were in atrioventricular node or intra-His, and HBP had a similar high success rate with HPSP [95.6% (109/114) vs. 96.3% (418/434), P=0.943] in these patients. In patients with QRS ≥ 120 ms, 69.7% (62/89) of AVB sites were at distal or inferior His bundle, and the success rate of HBP was only 25.0% (4/16), while the success rate of HPSP was as high as 79.5% (58/73), P<0.001. Conclusions: In patients with QRS<120 ms and atrioventricular node block or intra-His block, success rates of HBP and HPSP are similarly high and HBP might be considered as the first choice. In patients with QRS ≥ 120 ms and AVB site at distal or inferior His bundle, the success rate of HPSP is higher than that of HBP, suggesting LBBP should be considered as the first-line treatment option.

[Application and efficacy of the adjustment on left ventricular electrical delay and the distance between right and left ventricular pacing polar in optimizing the left ventricular pacing polar].

Objective: To investigate the application and efficacy of left ventricular (LV) electrical delay (LVED) and the distance of right ventricular(RV) pacing polar to LV(DRLV) in optimizing LV pacing polar. Methods: Heart failure (HF) patients who implanted cardiac resynchronization therapy (CRT) device with a LV quadripolar lead from January 2014 to January 2018 at General Hospital of Northern Theater Command were enrolled in the study. Measurements of LVED and DRLV of each polar of the lead were performed in patients with HF who underwent CRT with LV quadripolar lead. The principle in turn for polar selecting used for clinical LV pacing was the pacing polar: (1)without phrenic nerve stimulation(PNS); (2)with appropriate capture threshold; (3)not located in apical; (4)with maximal LVED; (5)with maximal DRLV. The LV pacing polar was selected for CRT according to the procedure. The distribution of target veins implanted with LV quadripolar lead were calculated. The percentage of biventricular pacing at 6-month follow-up was recorded. The following indexes were compared before and 6-month after surgery, including QRS duration, LV end-systolic volume(LVESV), LV ejection fraction(LVEF), LV end-diastolic dimension(LVEDD), 6 minute walking distance(6MWD), New York Heart Association(NYHA) class. The efficacy and echocardiographic efficacy of CRT was evaluated. Results: There were twenty-nine HF patients enrolled. The mean age of enrolled patients was(61.7±7.6)years old, nineteen (66%)of them were male. There were seventeen(59%) patients diagnosed as dilated cardiomyopathy and twelve(41%) patients as ischemic cardiomyopathy. All patients were successfully implanted with LV quadripolar lead into target veins, and all four pacing sites were also in target veins. Target veins were located in lateral veins in 15 patients (52%), anterior veins in 2 patients (7%), posterior veins in 11 patients (38%), and lateral branches of great cardiac veins in 1 patient (3%). After 6-month of follow-up, the percentage of biventricular pacing was greater than 95%.There were nineteen(66%) patients optimized LV pacing polar by the largest LVED and four (14%) patients by the DRLV. Of the 29 patients, 5(17%) patients used D1 as the pacing polar, 5(17%) patients used M2 as the pacing polar, 7(24%) patients used M3 as the pacing polar, and 12(41%) patients used P4 as the pacing polar. The pacing polars (D1, M2) of traditional bipolar lead were used in 10(34%) patients, and the LV quadripolar lead specific pacing polars (M3, P4) were used in 19(66%) patients.Compared to a LV quadripolar lead, the LV pacing polar (M3, P4) selected in 19(66%) patients were not achievable with the traditional LV bipolar lead (D1, M2). Preoperative QRS duration, LVESV, LVEF, LVEDD, 6MWD and NYHA class were (171±24)ms, (231±79)ml, (28±5)%, (74±11)mm, (294±103)m, (3.2±1.0)class and the postoperative 6-month were (130±12)ms, (158±73)ml, (36±10)%, (66±12)mm, (371±86)m, (1.9±0.5)class. These indexes were significantly improved after 6 months operation(P<0.001). 97% and 83% patients were responders of CRT as assessed by 6-month efficacy and echocardiographic efficacy. Conclusion: The maximal LVED and DRLV can be used to select LV pacing polar with a high rate of CRT response rate.

[Heart rate control in chronic heart failure patients received cardiovascular implantable electronic device therapy: effects of optimized medication].

Objective: To investigate the heart rate control situation of chronic heart failure (CHF) patients who received cardiovascular implantable electronic device (CIED) therapy, and to assess the heart rate control efficacy by optimized medication adjustment. Methods: We performed a perspective study in heart failure with reduced left ventricular ejection fraction (HFrEF) patients who received CIED according to guideline recommendations, patients were enrolled from January 2012 to January 2017. Resting heart rate (RHR) recorded by electrocardiogram after 10 minutes' rest and medication usage within 1 month were recorded at baseline. RHR less than 70 beats per minute (bpm) was regarded as well controlled. ß-receptor blockers and (or) ivabradine would be added in patients whose RHR were over 70 bpm. RHR after optimized medication adjustment was recorded during follow-up period. Results: One hundred and fifty patients were included in this study with average RHR (80.6±11.9) bpm. RHR was<70 bpm in 27.3% (41/150) patients at baseline and ß-receptor blockers was underused in 80.7% patients (88/109) whose RHR was>70 bpm. The overall RHR decreased to (73.1±10.4) bpm and percent of patients with RHR<70 bpm increased to 70.0% (105/150) after up-titration of ß-receptor blockers compared to baseline (χ2=52.958, P<0.001). Ivabradine was added in the rest 45 patients and RHR was<70 bpm in 43 out of 45 patients after ivabradine use. The overall RHR decreased to (67.1±2.7) bpm and percent of RHR<70 bpm significantly increased to 98.7% (148/150) (χ2=44.504, P<0.001 vs. up-titration of ß-receptor blockers only). Conclusion: RHR in CHF patients who received CIED therapy is not ideally controlled in this patient cohort, individual up-titration ofß-receptor blockers and ivabradine use may help to optimize RHR in these patients.

Mathematical Modeling of Yarn Dynamics in a Generalized Twisting System.

Twisting is an important process to form a continuous yarn from short fibres and to determine the structure and properties of the resultant yarn. This paper proposes a new theoretical model of yarn dynamics in a generalized twisting system, which deals with two important phenomena simultaneously, that is, twist generation and twist propagation. Equations of yarn motion are established and the boundary value problems are numerically solved by Newton-Raphson method. The simulation results are validated by experiments and a good agreement has been demonstrated for the system with a moving rigid cylinder as the twisting element. For the first time, influences of several parameters on the twisting process have been revealed in terms of twist efficiency of the moving rigid cylinder, propagation coefficients of twist trapping and congestion. It was found that the wrap angle and yarn tension have large influence on the twisting process, and the yarn torsional rigidity varies with the twisting parameters.

[Effect of endothelin on the release of angiotensin II from rat cardiovascular system].

The existence of angiotensin II immunoreactive substance in rat cardiovascular system was demonstrated by RIA and immunohistochemistry techniques. In atrium, aorta and cultured rat aorta smooth muscle cells, angiotensin II content is 7.2 + 2.7 pg/mg protein, 152.4 + 59.2 pg/mg protein and 3.5 + 0.8 pg/2 x 10(5) cells respectively. Endothelin, a potent vasoconstricting polypeptide, can enhance the release of angiotensin II from cultured rat aorta and aortic smooth muscle cells significantly. The results suggest that endothelin may be involved in the regulation of local blood flow and vascular tone, and it may also implicate the pathogenesis of some cardiovascular diseases such as cardiohypertrophy and vascular hypertrophy.