Large-view x-ray imaging for medical applications using the world's only vertically polarized synchrotron radiation beam and a single asymmetric Si crystal.

Objective.X-ray microangiography provides detailed information on the internal structure and function of a biological subject. Its ability to evaluate the microvasculature of small animals is useful for acquiring basic and clinical medical knowledge. The following three conditions are necessary to attain detailed knowledge of biological functions: (1) high temporal resolution with sufficient x-ray intensity, (2) high spatial resolution, and (3) a wide field of view. Because synchrotron radiation microangiography systems provide high sapatial resolution and high temporal resolution as a result of their high x-ray intensity, such systems have been developed at various synchrotron radiation facilities, starting with the photon factory, leading to numerous medical discoveries. However, the three aforementioned functions are incompatible with the use of synchrotron radiation because the x-ray intensity decreases when a wide field of view is obtained. To overcome these problems, we developed a new x-ray optical system for microangiography in rats using synchrotron radiation x-rays.Approach.Instead of using monochromatic synchrotron radiation x-rays with a conventional double-crystal monochromator, we used white synchrotron radiation x-rays and an asymmetric Si crystal to simultaneously monochromatize the beam and widen the field of view.Main results.The intensity profile and spatial resolution of the x-ray images were then evaluated. The proposed x-ray optics increased the x-ray intensity and beam width by factors of 1.3 and 2.7, respectively, compared with those of conventional monochromatic x-rays. In addition,in vivostudies on microangiography in rats were performed to confirm that the images had sufficient intensity, spatial resolution, and field of view. One of a series of images taken at 50 ms frame-1was shown as an example.Significance.This x-ray optics provides sufficient x-ray intensity, high spatial resolution, and a wide field of view. This technique is expected providing new insights into the evaluation of the vascular system.

Validity of Ipsilateral Internal Mammary Coronary Artery Bypass Graft of Arteriovenous Fistula.

BACKGROUND: In coronary artery bypass grafting (CABG) for haemodialysis patients, arteriovenous fistula can reduce blood flow from the internal mammary artery (IMA) graft. The purpose of this study was to delineate the rationale of ipsilateral IMA grafting to the arteriovenous fistula by assessing graft flow and patency. METHOD: The clinical records of 139 haemodialysis patients who underwent off-pump CABG, including IMA grafting to the left anterior descending artery (LAD) between April 2007 and December 2018, were retrospectively reviewed. Clinical outcomes and transit-time flowmetry results of IMA to LAD bypass grafts during off-pump CABG and postoperative angiography were examined. RESULTS: An ipsilateral IMA to the arteriovenous fistula (Ipsi-IMA) was used in 89 patients, and a contralateral IMA to the arteriovenous fistula (Contra-IMA) was used in 50 patients and no hospital deaths occurred. The mean graft flow and angiographic patency rate did not differ between the Ipsi-IMA and Contra-IMA groups. In patients with 51 to 90% stenosis of LAD, there was no significant difference in the mean graft flow. In comparison, in the patients with 91 to 100% stenosis of LAD, the mean graft flow in the Ipsi-IMA group was significantly lower than that in the Contra-IMA group (p=0.03). Kaplan-Meier analyses showed a 5-year survival rate of 57.6% for Ipsi-IMA and 64.8% for Contra-IMA (p=0.47). CONCLUSIONS: In the revascularisation of the LAD, the graft patency rate of the Ipsi-IMA was not inferior to that of the Contra-IMA. However, when the LAD has 91 to 100% stenosis, a Contra-IMA to arteriovenous fistula may be beneficial in terms of sufficient flow capacity.

Total arch replacement using frozen elephant trunk technique with Frozenix for distal aortic arch aneurysms.

OBJECTIVES: Total arch replacement (TAR) using an endovascular approach has been initially introduced as the frozen elephant trunk technique (FET). In our institute, TAR using the FET with Frozenix has been used as the first-line treatment for distal aortic arch aneurysms since 2014. This study aimed to evaluate the early and long-term outcomes and demonstrate the efficacy of this procedure. METHODS: Between 2014 and 2021, 121 consecutive patients were treated with TAR using the FET with Frozenix for distal aortic arch aneurysms. Early and long-term outcomes were retrospectively analysed. RESULTS: The 30-day mortality rate was 2.5% (3/121). Of postoperative complications, paraplegia due to spinal cord injury occurred in 2 (1.7%) patients, stroke in 12 (9.9%) and acute renal failure in 10 (8.3%). At follow-up, 23 secondary aortic interventions were required and 8 (6.6%) patients underwent intended secondary thoracic endovascular aortic repair for residual descending aortic aneurysm. Late and aortic-related deaths occurred in 16 (13.2%) and 4 (3.3%) patients, respectively. The overall long-term survival rates at 1, 3 and 5 years were 87.6%, 83.1% and 65.4%, respectively, while the rates of freedom from aortic-related death at 1, 3 and 5 years were 95.7%, 95.7% and 84.8%, respectively. CONCLUSIONS: TAR using the FET with Frozenix for distal aortic arch aneurysms has acceptable early mortality and morbidity. Spinal cord injury and paraplegia occur less frequently than previously reported. The technique has satisfactory long-term survival and freedom from aortic-related death.

An autopsy case of aortic dissection due to giant cell arteritis.

Giant cell arteritis (GCA) is a systemic vasculitis affecting mainly large and medium-sized arteries. GCA sometimes involves the aorta and its major branches and causes aortic dissection as a rare complication. We have experienced an autopsy case of aortic dissection due to GCA. The patient was an 87-year-old Japanese woman with Stanford type A aortic dissection who died 7 days after admission. Two years previously she had been diagnosed as having abdominal aortic aneurysm and undergone endovascular aneurysm repair (EVAR). Although she had no characteristic symptoms of GCA, autopsy revealed marked granulomatous inflammation in the dissected area and coronary arteries. Active arteritis was evident not only in the arteries of the upper extremity but also those in the lower extremity. Granulomatous inflammation was not evident in the aneurysm. The aortic dissection might have been an initial manifestation of GCA. We report the regions of GCA extension and its histology in detail.

The change in the mitral-septal angle after surgery for atrial functional mitral regurgitation.

OBJECTIVE: The optimal surgical strategy for atrial functional mitral regurgitation remains uncertain. Preoperative mitral-septal angle ≤ 70° has been reported as a risk factor for an abnormal vortex pattern in mitral valve repair. This study aimed to elucidate the change in the mitral-septal angle after surgery for atrial functional mitral regurgitation and its effect on the mid-term outcomes. METHODS: Forty patients underwent mitral valve repair for atrial functional mitral regurgitation. The mitral-septal angle was defined as the angle between the mitral annulus and the anteroseptal wall of the left ventricular mid-portion in the parasternal long-axis view on transthoracic echocardiography. All patients underwent mitral ring annuloplasty. Left atrial plication was performed in nine patients. The mean clinical follow-up period was 42 ± 24 months. RESULTS: The ratio of left atrial volume to left ventricular end-systolic volume was negatively correlated with the preoperative mitral-septal angle. The postoperative mitral-septal angles were significantly smaller than the preoperative ones. The mitral-septal angle decreased with a decrease in the mitral annuloplasty ring size. Patients who underwent left atrial plication tended to show an increase in the mitral-septal angle postoperatively. There were no significant differences in mid-term morbidities, including heart failure, requiring re-hospitalization and mortalities between patients with postoperative MSA > 70° and those with postoperative MSA ≤ 70°. CONCLUSIONS: Mitral ring annuloplasty negatively changed the mitral-septal angle, while left atrial plication may induce a positive change to the mitral-septal angle. An association between the mitral-septal angle and mid-term outcomes was not revealed in this study.

Trapezoidal resection of an elongated anterior mitral leaflet and Alfieri stitch in hypertrophic cardiomyopathy.

BACKGROUND: In individuals with hypertrophic obstructive cardiomyopathy, elongated anterior mitral leaflets are commonly associated with systolic anterior motion. In patients with mild septal hypertrophy, a myectomy is considered insufficient to relieve systolic anterior motion and left ventricular outflow tract obstruction. CASE PRESENTATION: In the patient, who had relatively mild septal hypertrophy, the section of the anterior leaflet protruding into the left ventricular outflow tract was resected, concomitant with septal myectomy and the relocation of the papillary muscles. An edge-to-edge stitch was placed at the uppermost segment of the coaptation zone. Using these manoeuvres, systolic anterior motion, left ventricular outflow tract obstruction and mitral regurgitation were successfully resolved postoperatively. CONCLUSIONS: We describe a surgical technique with an edge-to-edge suture for the resection of an elongated anterior mitral leaflet. In combination with septal myectomy and relocation of the papillary muscles, this technique is a simple and viable option, especially when septal hypertrophy is not severe.

Midterm results of mitral valve repair for atrial functional mitral regurgitation: a retrospective study.

BACKGROUND: Annular dilation by left atrial remodeling is considered the main cause of atrial function mitral regurgitation. Although acceptable outcomes have been obtained using mitral ring annuloplasty alone for atrial functional mitral regurgitation, data assessing outcomes of this procedure are limited. Therefore, we aimed to assess midterm outcomes of mitral valve repair in patients with atrial functional mitral regurgitation. METHODS: We retrospectively studied 40 patients (mean age: 69 ± 9 years) who had atrial fibrillation that persisted for > 1 year, preserved left ventricular ejection fraction of > 40%, and mitral valve repair for atrial functional mitral regurgitation. The mean clinical follow-up duration was 42 ± 24 months. RESULTS: Mitral ring annuloplasty was performed for all patients. Additional repair including anterior mitral leaflet neochordoplasty was performed for 22 patients. Concomitant procedures included maze procedure in 20 patients and tricuspid ring annuloplasty in 31 patients. Follow-up echocardiography showed significant decreases in left atrial dimensions and left ventricular end-diastolic dimensions. Recurrent mitral regurgitation due to ring detachment or leaflet tethering was observed in five patients and was seen more frequently among those with preoperative left ventricular dilatation. Three patients without tricuspid ring annuloplasty or sinus rhythm recovery by maze procedure developed significant tricuspid regurgitation. Five patients who underwent the maze procedure showed sinus rhythm recovery. Rates of freedom from re-admission for heart failure at 1 and 5 years after surgery were 95 and 86%, respectively. CONCLUSIONS: Mitral valve repair is not sufficient to prevent recurrent atrial functional mitral regurgitation in patients with preoperative left ventricular dilatation. Tricuspid ring annuloplasty may be required for long-term prevention of significant tricuspid regurgitation.

Rejuvenation of mesenchymal stem cells by extracellular vesicles inhibits the elevation of reactive oxygen species.

Aging induces numerous cellular disorders, such as the elevation of reactive oxygen species (ROS), in a number type of cells, including mesenchymal stem cells (MSCs). However, the correlation of ROS and impaired healing abilities as well as whether or not the inhibition of elevating ROS results in the rejuvenation of elderly MSCs is unclear. The rejuvenation of aged MSCs has thus recently received attention in the field of regenerative medicine. Specifically, extracellular vesicles (EVs) act as a novel tool for stem cell rejuvenation due to their gene transfer ability with systemic effects and safety. In the present study, we examined the roles of aging-associated ROS in the function and rejuvenation of elderly MSCs by infant EVs. The data clearly showed that elderly MSCs exhibited the downregulation of superoxide dismutase (SOD)1 and SOD3, which resulted in the elevation of ROS and downregulation of the MEK/ERK pathways, which are involved in the impairment of the MSCs' ability to decrease necrotic area in the skin flap model. Furthermore, treatment with the antioxidant Edaravone or co-overexpression of SOD1 and SOD3 rescued elderly MSCs from the elevation of ROS and cellular senescence, thereby improving their functions. Of note, infant MSC-derived EVs rejuvenated elderly MSCs by inhibiting ROS production and the acceleration of cellular senescence and promoting the proliferation and in vivo functions in both type 1 and type 2 diabetic mice.

Early and long-term results of total arch replacement with the frozen elephant trunk technique for acute type A aortic dissection.

OBJECTIVES: We evaluated the operative and long-term outcomes of the frozen elephant trunk (FET) technique for acute type A aortic dissection. METHODS: This study evaluated 426 consecutive patients who underwent aortic repair for acute type A aortic dissection from June 2007 to December 2018 at our centre. Of these, 139 patients underwent total arch replacement with FET (FET group), and 287 underwent other procedures (no FET group). Ninety-two patients in the FET group were matched to 92 patients in the no FET group by using propensity score matching analysis. RESULTS: Thirty-day mortality and neurological dysfunction were not significantly different between the FET and no FET groups (1.4% vs 2.4%, P = 0.50 and 5.0% vs 6.3%, P = 0.61, respectively). Long-term survival was better in the FET group than in the no FET group (P = 0.008). Freedom from distal thoracic reintervention was similar in the FET and no FET groups (P = 0.74). In the propensity-matched patients, freedom from aortic-related death was better in the FET group than in the no FET group (P = 0.044). CONCLUSIONS: Operative outcomes showed no significant difference between the 2 groups. FET contributes to better long-term survival in patients with acute type A aortic dissection.

Early First-Generation Trifecta Valve Failure: A Case Series and a Review of the Literature.

BACKGROUND: The Trifecta valve (Abbott, St Paul, MN) has excellent hemodynamic performance with acceptable rates of freedom from structural valve degeneration. However, some recent studies have reported early Trifecta valve failure. Here, we report a case series of seven Trifecta valve failures with a review of the literature. METHODS: Of 107 implantations of Trifecta bioprostheses between 2012 and 2014, we encountered seven Trifecta valve failures (6.5%). Failure of a 19-mm Trifecta valve occurred in 1 patient, failure of a 21-mm Trifecta valve occurred in 5 patients, and failure of a 23-mm Trifecta valve occurred in 1 patient. The mean duration of valve durability was 51 ± 16 months. The mean effective orifice area index on the first echocardiogram after Trifecta valve implantation was 0.96 ± 0.26. The mode of presentation was prosthetic valve stenosis in 3 patients and severe aortic regurgitation in 4 patients. RESULTS: Six patients underwent redo surgical aortic valve replacement. The common pathologic findings were circumferential pannus formation with noncoronary cusp tear and leaflet calcification. The rates of preoperative end-renal stage disease and postoperative prosthesis-patient mismatch were higher in patients with Trifecta valve failure. The incidence of early Trifecta valve failure was 3.1% at 48 months and 13.1% at 72 months. CONCLUSIONS: In our experience, early Trifecta valve failure was caused by cusp tears or leaflet calcification. Patients with end-renal stage disease and prosthesis-patient mismatch should be closely followed. Some patients with cusp tears may require urgent surgery.

Recurrent mitral regurgitation after mitral valve repair for bileaflet lesions in the modern era.

BACKGROUND: Good mid-term durability of mitral valve repair of bileaflet lesions has been reported; however, patients may develop failure during follow-up. This study assessed late outcomes and mechanisms of failure associated with mitral valve repair of bileaflet lesions. METHODS: Fifty-six patients (mean age 67 ± 12 years) underwent mitral valve repair of bileaflet lesions due to degenerative disease in 2011-2018. Mitral annuloplasty was added to all procedures except for 1 patient with annular calcification. Mitral valve lesions were identified by surgical inspection. Mean clinical and echocardiography follow-up occurred at 2.7 ± 2.1 and 2.5 ± 1.9 years, respectively. RESULTS: Additional mitral valve repair techniques involved triangular resection (n = 15 patients), quadrangular resection with sliding plasty (n = 12), neochordoplasty (n = 52), and commissural plication (n = 26). Prolapse of ≥2 anterior and posterior leaflet scallops occurred in 22 (39%) and 30 (54%) patients, respectively. During follow-up, 10 (17.8%) patients developed moderate or severe mitral regurgitation. Whereas prolapse or tethering was observed early after neochordoplasty or quadrangular resection, recurrent regurgitation occurred late after commissural repair. Five-year freedom from recurrent moderate or severe mitral regurgitation rates was 71.1 ± 11.0%. CONCLUSIONS: Seventeen percent of patients developed recurrent mitral regurgitation during follow-up. Repair failure in the early phase occurred owing to aggressive resection of the posterior mitral leaflet or maladjustment of the artificial neochordae. Recurrent mitral regurgitation might occur in the late phase even after acceptable commissural repair. A sequential approach may be useful to improve the quality of mitral valve repair in bileaflet lesions.

Type D personality is a predictor of prolonged acute brain dysfunction (delirium/coma) after cardiovascular surgery.

BACKGROUND: Previous studies have shown a relationship between delirium and depressive symptoms after cardiac surgery with distress personalities linking to negative surgical outcomes. The aim of the present study is to further investigate the association between patients with Type D (distressed) personality with regards to delirium after cardiac surgery. METHODS: We conducted a consecutive-sample observational cohort pilot study with an estimated 142 patients needed. Enrollment criteria included patients aged ≥18 years who were undergoing planned cardiovascular, thoracic and abdominal artery surgery between October 2015 to August 2016 at the University of Tsukuba Hospital, Japan. All patients were screened by Type-D Personality Scale-14 (DS14) as well as the Hospital Anxiety and Depression Scale (HADS) the day before surgery. Following surgery, daily data was collected during recovery and included severity of organ dysfunction, sedative/analgesic exposure and other relevant information. We then evaluated the association between Type D personality and delirium/coma days (DCDs) during the 7-day study period. We applied regression and mediation modeling for this study. RESULTS: A total of 142 patients were enrolled in the present study and the total prevalence of delirium was found to be 34% and 26% of the patients were Type D. Non-Type D personality patients experienced an average of 1.3 DCDs during the week after surgery while Type D patients experienced 2.1 days over the week after surgery. Multivariate analysis showed that Type D personality was significantly associated with increased DCDs (OR:2.8, 95%CI:1.3-6.1) after adjustment for depressive symptoms and clinical variables. Additionally, there was a significant Type D x depression interaction effect (OR:1.7, 95% CI:1.2-2.2), and depressive symptoms were associated with DCDs in Type D patients, but not in non-Type D patients. Mediation modeling showed that depressive symptoms partially mediated the association of Type D personality with DCDs (Aroian test =0.04). CONCLUSIONS: Type D personality is a prognostic predictor for prolonged acute brain dysfunction (delirium/coma) in cardiovascular patients independent from depressive symptoms and Type D personality-associated depressive symptoms increase the magnitude of acute brain dysfunction.

Cardiac Methotrexate-Induced Lymphoproliferative Disorder.

Methotrexate has been reported as an immunosuppressive agent associated with lymphoproliferative disorders. This report describes the case of a cardiac methotrexate-induced lymphoproliferative disorder that could be differentiated from a sinus of Valsalva aneurysm rupture by cardiac magnetic resonance imaging and fluorine-18 (18F)-fluorodeoxyglucose positron emission tomography combined with computed tomography. The definitive diagnosis was made by a tissue biopsy that was concomitantly performed with sinus of Valsalva aneurysm repair. Significant regression was seen in response to methotrexate withdrawal. To the best of our knowledge, this is the first case of a cardiac methotrexate-induced lymphoproliferative disorder.

Current mechanisms of low graft flow and conduit choice for the right coronary artery based on the severity of native coronary stenosis and myocardial flow demand.

OBJECTIVES: We investigated current mechanisms causing low graft flow (LGF) following coronary artery bypass grafting, particularly for the right coronary artery (RCA). METHODS: We retrospectively assessed 230 individual bypass grafts as the sole bypass graft for the RCA using preoperative and postoperative quantitative angiography. Overall, 155 in-situ gastroepiploic arteries (GEAs) and 75 saphenous vein grafts (SVGs) were included. The size and status of the revascularised area were examined to determine whether these factors were associated with LGF (defined as ≤ 20 mL/min with intraoperative flowmetry). A distal lesion was defined as stenosis at segment #4, whereas a proximal lesion was stenosis at #1, #2 and #3. RESULTS: Graft flow in the SVG and the GEA for distal lesion was significantly less compared with that for proximal lesion (34 ± 26 vs. 60 ± 46, p < 0.0001 and 22 ± 12 vs. 43 ± 28, p = 0.0004, respectively). For proximal lesion, LGF was significantly more frequent when the minimal luminal diameter was over 1.27 compared with when it was less than 1.27 (p = 0.02). Prior myocardial infarction significantly correlated with LGF in the GEA (p = 0.007) and the SVG (p = 0.03). In 55 bypass grafts with LGF, the causes were competitive flow in 20.0%, small revascularised area in 38.1% and prior myocardial infarction in 32.7%. CONCLUSIONS: Along with the current strategy based on the severity of native coronary stenosis, the incidence of competitive flow decreased remarkably. This resulted in flow demand, myocardial status and collateral vessels more influential on graft patency.

Early- and long-term results of thoracic endovascular aortic repair for blunt traumatic thoracic aortic injury: a single-centre experience.

OBJECTIVES: Endovascular repair has been proposed as an alternative to classical surgical repair for the management of blunt traumatic thoracic aortic injury. However, the long-term outcomes of endovascular repair and the risks of left subclavian coverage remain unclear. METHODS: From April 2001 to August 2018, 33 patients with blunt traumatic thoracic aortic injury underwent endovascular repair in our institution. A follow-up computed tomography and a clinical examination were performed before discharge and at 1 month, and yearly or every 2 years thereafter. RESULTS: The mean age was 45 ± 19 years. The technical success rate was 100%. Complete coverage of the left subclavian artery (LSCA) was performed in 20 patients (60.6%). Among 20 patients with coverage of the LSCA, revascularization was performed in 1 patient. No in-hospital deaths occurred. The clinical follow-up rate was 97%, with a mean period of 7 years and a maximum of 18 years. The survival rates were 100% at 1 year, 95% at 5 years and 88.7% at 10 years after the event. Among the 5 patients (20%) who developed neurological complications, 1 who had undergone implantation of a 200-mm long stent graft and LSCA coverage without revascularization developed paraplegia during the long-term follow-up. CONCLUSIONS: This study demonstrates that the endovascular treatment of blunt traumatic thoracic aortic injury is a safe and effective therapeutic method over a long-term follow-up period. LSCA coverage and long stent graft placement might be indications for revascularization to prevent spinal cord injury.

Intraoperative transit-time flowmetry in patients undergoing coronary surgery to determine relationships between graft flow and patency and prior coronary interventions and flow demand: a retrospective study.

BACKGROUND: The aim of this study was to delineate impacts of percutaneous coronary intervention (PCI), flow demand, and status of myocardium on graft flow. METHODS: We retrospectively assessed 736 individual coronary artery bypass grafts that had been created as the sole bypass graft for a vascular region in 405 patients. The grafts comprised 334 internal thoracic artery (ITA) to left anterior descending (LAD), 129 ITA and 65 saphenous vein grafts (SVG) to left circumflex (LCX), and 142 gastroepiploic artery (GEA) and 66 SVG to right coronary artery (RCA). Minimal luminal diameter, size of revascularized area, history of myocardial infarction, and PCI in the relevant area were examined to determine whether these factors are associated with flow insufficiency (FI), which was defined as ≤ 20 mL/min. RESULTS: FI developed in 123/736 grafts (16.7%) and correlated significantly with stenosis in the distal portion (23.0% vs. 12.8%, p = 0.0003). Prior myocardial infarction significantly correlated with FI in GEA-RCA (p = 0.002) and ITA-LCX grafts (p = 0.04). There was a history of PCI to the LAD (PCI group) in 54 ITA to LAD bypass grafts (16.2%), whereas the remaining 280 had no history of PCI to the LAD (no-PCI group). Graft flow was significantly greater in the no-PCI than in the PCI group (53 ± 29 vs. 42 ± 27; p = 0.006). The incidences of FI and graft failure were significantly higher in the PCI than the no-PCI group (22.2%, vs. 8.2%; p = 0.003; 9.2% vs. 1.8%; p = 0.003, respectively). CONCLUSIONS: Prior PCI has a negative impact on graft flow. The influences of small revascularized area, myocardial infarction, and PCI are greater, necessitating consideration of factors associated with flow demand or microvasculature when planning revascularization.

A new method for visualizing pulmonary artery microvasculature using synchrotron radiation pulmonary microangiography: the measurement of pulmonary arterial blood flow velocity in the high pulmonary blood flow rat model.

BACKGROUND: Increased pulmonary blood flow (PBF) and shear stress may provoke irreversible vascular remodeling, yet invasive visualization of the microvasculature complicates monitoring. A non-invasive imaging methodology would therefore safely provide mechanistic insights into the progression of high PBF-induced vascular remodeling. PURPOSE: To establish a novel microvasculature visualization method using synchrotron radiation pulmonary microangiography (SRPA) that can also calculate PBF velocity in vivo. MATERIAL AND METHODS: A high PBF rat model was established by making a fistula between the abdominal aorta and inferior vena cava. After eight weeks, SRPA was performed and the dynamic density changes in the right lower pulmonary artery (PA) were calculated by software. SRPA was performed with a HARP (High-Gain Avalanche Rushing amorphous Photoconductor) receiver. PBF velocity was calculated by contrast medium transit time within the PA. All data were presented as mean ± standard error (SE). Student's t-test was used for comparison between the two groups. RESULTS: High dynamic spatial and contrast resolution from SRPA in the PA allowed for clear pulmonary microangiography and accurate detection of higher PBF in the rat model (82.3 ± 8.5 mm/s high-PBF group vs. 46.1 ± 4.3 mm/s control group, P < 0.01). CONCLUSIONS: These novel results demonstrate that SRPA was useful in both visualizing the dynamic flow distribution within the microvasculature and calculating PBF velocity. This newly developed, non-invasive technology may become a powerful tool in clarifying the mechanism of vascular remodeling associated with high PBF-induced shear stress.

Landiolol Hydrochloride Rapidly Controls Junctional Ectopic Tachycardia After Pediatric Heart Surgery.

OBJECTIVES: Junctional ectopic tachycardia is a supraventricular tachyarrhythmia with atrioventricular dissociation that causes life-threatening postsurgical conditions in pediatric heart patients. This study evaluates the efficacy of landiolol hydrochloride for managing junctional ectopic tachycardia. DESIGN: A single-center retrospective study. SETTING: PICU at the university hospital. PATIENTS: Of 561 pediatric patients who underwent open-heart surgery between 2006 and 2017, 10 patients developed sustained junctional ectopic tachycardia and were selected for landiolol treatment. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Landiolol decreased mean heart rate significantly from 206.1 ± 14.5 to 158.0 ± 8.6 beats/min within 2 hours after administration (p < 0.01). Mean time to achieve 20% heart rate reduction was 2.1 ± 0.5 hours. Systolic blood pressure between pre and post landiolol administration did not change significantly (72.6 ± 5.9 to 79.7 ± 6.2 mm Hg). Once junctional heart rate was sufficiently suppressed, atrioventricular sequential pacing was introduced to stabilize hemodynamics. Nine of 10 cases (90%) had atrioventricular sequential pacing to maintain appropriate heart rate and restore atrioventricular synchronicity under suppressed junctional heart rate. Subsequently, eight of 10 cases (80%) were converted to regular sinus rhythm within 24 hours after starting landiolol administration. The average time to achieve sinus rhythm conversion was 7.9 ± 3.4 hours. CONCLUSIONS: Landiolol rapidly suppresses junctional heart rate in junctional ectopic tachycardia after pediatric heart surgery without significant blood pressure compromises. Subsequent atrioventricular sequential pacing was effective at restoring atrioventricular synchronicity and stabilizing hemodynamics. Combining junctional rate control with landiolol and atrioventricular sequential pacing is therefore suggested as a promising option for prompt management of postoperative junctional ectopic tachycardia.

Aging impairs beige adipocyte differentiation of mesenchymal stem cells via the reduced expression of Sirtuin 1.

In the body, different types of adipose tissue perform different functions, with brown and beige adipose tissues playing unique roles in dissipating energy. Throughout life, adipocytes are regenerated from progenitors, and this process is impaired by aging. One of the progenitors of adipocytes are mesenchymal stem cells (MSCs), which have recently become a promising tool for stem cell therapy. However, whether or not aging impairs the brown/beige adipocyte differentiation of adipose tissue-derived MSCs (AT-MSCs) remains unclear. In the present study, we isolated AT-MSCs from two different age groups of donors (infants and elderly subjects) and examined the effects of aging on the AT-MSC brown/beige adipocyte differentiation ability. We found that none of the AT-MSCs expressed Myf5, which indicated the beige (not brown) differentiation ability of cells. Of note, an inverse correlation was noted between the beige adipocyte differentiation ability and age, with AT-MSCs derived from elderly donors showed the most severely reduced function due to induced cellular senescence. The impaired expression of Sirtuin 1 (Sirt1) and Sirt3 proved to be responsible for the induction of senescence in elderly AT-MSCs; however, only Sirt1 was directly involved in the regulation of beige adipocyte differentiation. The overexpression of Sirt1 impaired the p53/p21 pathway, thereby preventing elderly AT-MSCs from entering senescence and restoring the beige differentiation ability. Thus, our study represents the important role of Sirt1 and senescence in the regulation of beige adipocyte differentiation during aging.

Predictors of Pericardial Effusion in Patients Undergoing Pulmonary Artery Banding.

BACKGROUND: Although pulmonary artery banding (PAB) is a common palliative procedure for pediatric heart malformation, there are concerns of pressure overload and concomitant immune reactions in the right ventricle causing postsurgical complications such as pericardial effusion. At this time, no clear guidelines as to potential risk factors or procedural contraindications have been widely disseminated. Therefore, a study was undertaken to examine wide-ranging factors to find potential biomarkers for postsurgical pericardial effusion formation risk. METHODS: A retrospective study was conducted on all cardiac surgeries performed over an eight-year period, and the main inclusion criterion was pericardial effusion development after PAB that required surgical drainage. Nine cases were then analyzed against a control group of 45 cases with respect to body measurements, concomitant surgeries, genetic screens, laboratory tests results, and cardiac function parameters. RESULTS: Trisomy 21 was strongly associated with the development of severe pericardial effusion after PAB, and postoperative serum albumin levels in patients with trisomy 21 were associated with pericardial effusion development. Other parameters showed no significant correlation with pericardial effusion development. CONCLUSIONS: Our data indicate a strong association between trisomy 21 and pericardial effusion requiring drainage after PAB, which is in line with translational research findings. Pressure overload from PAB may play a role in the formation of severe pericardial effusion that is exacerbated by cardiac structural defects commonly associated with trisomy 21. Surgical teams should therefore use caution and plan to implement drainage in PAB cases, and postoperative serum albumin may serve as a useful biomarker for pericardial effusion formation.