A Novel Technique for the Avoiding Catheter Dislodgment Caused by Atrio-Ventricular Dissociation after Elimination of the Accessory Pathway

We hypothesized that the atrio-ventricular (AV) dissociation occurring after elimination of the accessory pathway conduction during right ventricular (RV) pacing made the stability of the ablation catheter worse. We confirmed this hypothesis by using a pacing model. As a simulation model, sequential ventriculo-atrial (VA) pacing was designed and stud ied in 20 pa tients without VA conduction. Prior to the sequential VA pacing, 3 catheters were positioned in the RV, right atrium (RA) and at the tricuspid valve annulus (TVA), respectively. The sequential VA pacing consisted of continuous RV pacing at a cycle length of 600 ms and RA pacing. The RA was paced at an interval of 125 ms following the RV pacing. To induce AV dissociation, RA pacing was abruptly terminated during continuous sequential VA pacing. We observed the motion of the catheter tip on the TVA before and after RA pacing using fluoroscopy in the 30? right anterior oblique (RAO) and 45? left anterior oblique (LAO) views. The catheter tip position in the end-systolic and end-diastolic phases was confirmed in each projection, and the distance of the catheter tip between these 2 phases was measured. The mean value of the catheter tip distance between the 2 phases obtained with sequential VA pacing and fusion beats was 7.5 ± 3.2 and 21.0 ± 8.3 mm in the RAO (P < 0.001) and 8.0 ± 4.5 and 19.0 ± 8.6 mm in the LAO views (P < 0.001), respectively. Further, we proposed a new pacing maneuver to stabilize the ablation catheter position after the elimination of accessory pathway conduction. Using sequential VA pacing, we examined catheter tip movement during RF current delivery in 6 patients with the concealed Wolff-Parkinson-White syndrome. During RF current delivery, catheter dislodgment did not occur in any patients after the accessory pathway was eliminated when no fusion beats occurred. In conclusion, AV dissociation occurring after elimination of the accessory pathway conduction during RV pacing worsened the stability of the ablation catheter. Furthermore, a new pacing maneuver during the RF application provided a useful method for maintaining stable catheter position for catheter ablation of accessory pathways

Effect of Subcutaneous Adrenaline/Saline/Lidocaine Injection on Split-Thickness Skin Graft Donor Site Wound Healing

[Background] Subcutaneous injection of tumescent solution, which contains local anesthetic, adrenaline, and saline, before split-thickness skin graft harvesting, shows a significant hemostatic effect. This method can reduce the initial bleeding from the donor site. The aim of this study is to assess the benefits of controlling the bleeding from donor sites by tumescent injection. A randomized, controlled trial was performed to compare the wound healing of split-thickness skin graft donor sites treated with or without tumescent injection. [Methods] This randomized, controlled trial examined donor site healing days as the main measure of outcome. postoperative pain, donor site ulceration, and scar quality were evaluated as secondary outcome measures. Patients planned for split-thickness skin graft harvest were randomly assigned to receive either pre-harvest subcutaneous injection of local anesthetic, adrenaline, and saline solution (tumescent solution) (Group 1) or post-harvest application of adrenaline solution-soaked gauze to the skin graft donor sites (Group 2). Donor sites were treated with calcium alginate dressings after graft harvesting. On the 10th postoperative day, the dressings were removed and donor site healing were measured. Follow-up evaluation of scar quality was performed 6 months after surgery. Postoperative pain was evaluated on the 1st day after operating. [Results] Forty-five patients (26 males; average age 61.8 years) completed the late follow-up evaluation (6 months postoperatively), with 26 patients in group 1 and 19 in group 2. There were no significant differences between the two groups in any of the outcome measures. [Conclusion] Tumescent technique provides sufficient hemostasis in split skin graft donor sites, especially the initial bleeding just after graft harvesting, without any negative effects. Larger series should be studied to evaluate the effect in donor site wound healing

Hyperuricemia as a Risk Factor for Cardiovascular Diseases

Serum uric acid level above 7 mg/dl is defined as hyperuricemia, which gives rise to the monosodium urate (MSU), causing gout and urolithiasis. Hyperuricemia is an independent risk factor as well as a marker for hypertension, heart failure, atherosclerosis, atrial fibrillation, and chronic kidney disease. MSU crystals, soluble uric acid (UA), or oxidative stress derived from xanthine oxidoreductase (XOR) might be plausible explanations for the association of cardio-renovascular diseases with hyperuricemia. In macrophages, MSU activates the Nod-like receptor family, pyrin　domain containing 3(NLRP3) inflammasome, and proteolytic processing mediated by caspase-1 with enhanced interleukin (IL)-1β and IL-18 secretion. Soluble UA accumulates intracellularly through UA transporters (UAT) in vascular and atrial myocytes, causing endothelial dysfunction ad atrial electrical remodeling. XOR generates reactive oxygen species (ROS) that lead to cardiovascular diseases. Since it remains unclear whether asymptomatic hyperuricemia could be a risk factor for cardiovascular and kidney diseases, European and American guidelines do not recommend pharmacological treatment for asymptomatic patients with cardio-renovascular diseases. The Japanese guideline, on the contrary, recommends pharmacological treatment for hyperuricemia with CKD to protect renal function, and it attaches importance of the cardio-renal interaction for the treatment of asymptomatic hyperuricemia patients with hypertension and heart failure

Hemodynamic Analysis of a Microanastomosis Using Computational Fluid Dynamics

[Background] Technical issues in free flap transfer, such as the selection of recipient vessels and the positioning and method of anastomosis of the vascular pedicle, have been the subject of vigorous debate. Recent developments in computational fluid dynamics (CFD) have enabled the analysis of blood flow within microvessels. In this study, CFD was used to analyze hemodynamics in a microanastomosis. [Methods] In the fluid calculation process, the fluid domain modelizes microvessels with anastomosis. The inlet flow conditions were measured as venous waveform, and the fluid is simulated as blood. Streamlines (SL), wall shear stress (WSS), and oscillatory shear index (OSI) at the anastomosis were visualized and analyzed for observing effects from the flow field. [Results] Some flow disruption was evident as the SL passed over the sutures. The maximum recorded WSS was 13.37 Pa where the peak of a suture was exposed in the lumen. The local maximum value of the OSI was 0.182, recorded at the base of the anastomosis on the outflow side. [Conclusion] In the ideal anastomosis, the SL is disrupted as little as possible by the sutures. The WSS indicated that thrombus formation is unlikely to occur at suture peaks, but more likely to occur at the base of sutures, where the OSI is high. Tight suture knots are important in microanastomosis

Sensitivity and Specificity of Denaturing HPLC to Detect MYBPC3 Gene Mutations in Hypertrophic Cardiomyopathy

Denaturing high-performance liquid chromatography (DHPLC), which has recently been developed as an automated method to detect mutations, is at least ten times less expensive than the direct sequencing method; however, its sensitivity and specificity for cardiac myosin-binding protein C (MYBPC3) gene mutations in hypertrophic cardiomyopathy have not been reported yet. A mutation analysis of exons 1 to 35 of MYBPC3 gene from 20 Japanese patients with hypertrophic cardiomyopathy was performed using DHPLC and direct sequencing. Compared to direct sequencing, the sensitivity and specificity of DHPLC were 87.5% and 97.42%, respectively. Its positive and negative predictive values were 41.18% and 99.74%. The positive and negative likelihood ratios were 33.95 and 0.13, and the prevalence was 2.02%. DHPLC showed high sensitivity and specificity for detecting MYBPC3 gene mutations in hypertrophic cardiomyopathy. The use of this complementary sequencing method should reduce the cost of detection of MYBPC3 gene mutations, and could be used to screen patients with hypertrophic cardiomyopathy

Clinical characteristics for distinguishing between acute cardiogenic pulmonary edema and community-acquired pneumonia in elderly patients: a prospective observational study

Heart failure and pneumonia are highly prevalent in elderly patients. We conducted a study to evaluate the differences in the patterns of symptoms, laboratory findings, and computed tomography (CT) results in elderly patients with acute cardiogenic pulmonary edema (ACPE) and community-acquired pneumonia (CAP). From January 1, 2015 to December 31, 2017, we studied 140 patients aged >75 years who were diagnosed with ACPE and CAP. Symptoms, laboratory findings, mean ostial pulmonary vein (PV) diameter and patterns on CT images were assessed. The primary measures of diagnostic accuracy were assessed using the positive likelihood ratio (LR+). The cutoff value of ostial PVs for differentiating patients with ACPE from CAP was evaluated using the receiver operating characteristic (ROC) analysis. Ninety-three patients with ACPE, 36 with CAP, and 11 with complicated ACPE/CAP were included. In patients with ACPE, edema (LR+ 5.4) was a moderate factor for rule-in, and a high brain natriuretic peptide level (LR+ 4.2) was weak. In patients with CAP, cough (LR+ 5.7) and leukocytosis (LR+ 5.2) were moderate factors for rule-in, while fever (LR+ 3.8) and a high C-reactive protein level (LR+ 4.8) were weak factors. The mean diameter of ostial PVs in patients with ACPE was significantly larger than that of patients with CAP (15.8± 1.8 mm vs 9.6±1.5 mm, p< 0.01). ROC analysis revealed that an ostial PV diameter cutoff of 12.5 mm was strong evidence for distinguishing ACPE from CAP with an area under the ROC curve of 0.99 and LR+ 36.0. In conclusion, as ACPE and CAP have similar symptoms and laboratory findings, dilated ostial PVs were useful in characterizing CT images to distinguish ACPE from CAP

Smooth muscle cell sheet transplantation preserve cardiac function and minimize cardiac remodeling in a rat myocardial infarction model

Background: We examined whether a vascular smooth muscle cell (SMC) sheet is effective in the treatment of a rat myocardial infarction (MI) model. Methods: We examined the effect of SMC sheet on the cardiac function and cardiac remodeling in a rat MI model in comparison with their effect of dermal fibroblast (DFB) sheet in vivo. Furthermore, we estimated the apoptosis and secretion of angiogenic factor of SMC under hypoxic condition in comparison with DFB. Seven days after MI, monolayer cell sheets were transplanted on the infarcted area (SMC transplantation group, SMC-Tx; DFB transplantation group, DFB-Tx; no cell sheet transplantation group, Untreated; neither MI nor cell sheet transplantation group, Sham). We evaluated cardiac function by echocardiogram, degree of cardiac remodeling by histological examination, and secretion of angiogenic growth factor by enzyme immunoassay. Results: Twenty-eight days after transplantation, SMC-Tx showed the following characteristics compared with the other groups: 1) significantly greater fractional area shortening (SMC-Tx, 32.3 ± 2.1 %; DFB-Tx, 23.3 ± 2.1 %; untreated, 25.1 ± 2.6 %), 2) suppressed left ventricular dilation, smaller scar expansion, and preserved wall thickness of the area at risk and the posterior wall, 3) decreased fibrosis, preserved myocardium in the scar area, and greater number of arterioles in border-zone, 4) tight attachment of SMC sheets on the scarred myocardium, and less apoptotic cell death. In in vitro experiments, SMCs secreted higher amounts of basic fibroblast growth factor (SMC, 157.7 ± 6.4 pg/ml; DFB, 3.1 ± 1.0 pg/ml), and showed less apoptotic cell death under hypoxia. Conclusions: Our results illustrate that transplantation of SMC sheets inhibited the progression of cardiac remodeling and improve cardiac function. These beneficial effects may be due to superior SMC survival