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Background: Cardiac catheterizations in horses are mainly performed in the right heart, as access to the left heart traditionally requires an arterial approach. Transseptal puncture (TSP) has been adapted for horses but data on follow‐up and closure of the iatrogenic atrial septal defect (iASD) are lacking. Hypothesis/Objectives: To perform TSP and assess postoperative complications and iASD closure over a minimum of 4 weeks. Animals: Eleven healthy adult horses. Methods: Transseptal puncture was performed under general anesthesia. Serum cardiac troponin I concentrations were measured before and after puncture. Weekly, iASD closure was monitored using transthoracic and intracardiac echocardiography. Relationship between activated clotting time and anti‐factor Xa activity during postoperative enoxaparin treatment was assessed in vitro and in vivo. Results: Transseptal puncture was successfully achieved in all horses within a median duration of 22 (range, 10‐104) minutes. Balloon dilatation of the puncture site for sheath advancement was needed in 4 horses. Atrial arrhythmias occurred in 9/11 horses, including atrial premature depolarizations (N = 1), atrial tachycardia (N = 5), and fibrillation (N = 3). Serum cardiac troponin I concentrations increased after TSP, but remained under the reference value in 10/11 horses. Median time to iASD closure was 14 (1‐35) days. Activated clotting time correlated with anti‐factor Xa activity in vitro but not in vivo. Conclusions and Clinical Importance: Transseptal puncture was successfully performed in all horses. The technique was safe and spontaneous iASD closure occurred in all horses. Clinical application of TSP will allow characterization and treatment of left‐sided arrhythmias in horses. [ABSTRACT FROM AUTHOR]

Background: Improved characterization of arrhythmias is based on minimally invasive catheterizations. However, these catheterizations have been poorly explored in horses because apart from 3‐dimensional (3D) mapping systems, continuous guidance of the catheter's position with adequate detail is difficult using current imaging modalities. Hypothesis: Position multiple electrophysiology catheters simultaneously at predetermined strategical positions in the heart using transthoracic echocardiographic guidance. Animals: Eight adult healthy horses. Methods: Observational study. Two electrophysiological studies were performed: 1 procedure with catheters positioned in the right heart in the standing sedated horse and 1 procedure under general anesthesia with catheters positioned in the left heart. Except for the coronary sinus catheter, each catheter positioning was simultaneously guided by right‐parasternal transthoracic echocardiography and 3D electro‐anatomical mapping. Results: For each catheter position, a central imaging plane was taken as the starting point, after which the imaging probe was shifted, rotated, and angulated to visualize the catheter over its entire length, including its distal electrode. Catheter positionings in the right heart and left ventricle were successfully guided in the majority of the horses whereas catheter positionings in the left atrium, and especially the pulmonary veins, were challenging to guide echocardiographically. Conclusions and Clinical Importance: Ultrasound guidance of catheters to specific positions useful for electrophysiological mapping was feasible in the right heart and left ventricle but challenging for the left atrium. This approach creates a perspective for minimally invasive arrhythmia diagnosis without the need for a 3D mapping system. Left parasternal views and intracardiac echocardiography might provide better guidance for left atrial positions. [ABSTRACT FROM AUTHOR]

Background: Recently, treatment of equine atrial tachycardia by three‐dimensional electro‐anatomical mapping (3D EAM) and radiofrequency catheter ablation (RFCA) has been described. Myocardial sleeves in the caudal vena cava and pulmonary veins are a potential trigger for initiation and perpetuation of atrial tachycardia and atrial fibrillation in the horse. Isolation of these myocardial sleeves by RFCA may be an effective treatment for these arrhythmias. Objectives: To describe the feasibility of 3D EAM and RFCA to isolate caudal vena cava and pulmonary veins in adult horses using 3D mapping and a contact force (CF)‐guided ablation system. Study design: In vivo experiments. Methods: 3D EAM and RFCA was performed in five horses without cardiovascular disease under general anaesthesia, using the CF‐guided system CARTO®3. Point‐by‐point RFCA aimed for isolation of caudal vena cava and pulmonary veins. Radiofrequency energy was delivered in power‐controlled mode with a target power of 45 W, CF between 10 and 15 g and 30 mL/min irrigation rate, until an ablation‐index of 450–500 was reached. Results: In the right atrium, myocardial sleeves of the caudal vena cava were isolated (n = 5). In the left atrium, isolation of ostium II (n = 3), ostium III (n = 1) and ostium I, II and III en bloc (n = 1) was performed. Successful isolation was confirmed by entrance and exit block. Main limitations: Horses were euthanised at the end of the procedure, so long term effects such as potential reconnection of isolated veins could not be studied. Conclusions: This is the first description of 3D EAM and RFCA with CARTO®3 in horses, thereby showing the technical feasibility and successful caudal vena cava and pulmonary vein isolation. CF measurement allowed monitoring of catheter‐tissue contact, resulting in efficient acute lesion creation as confirmed by entrance and exit block. This is a promising treatment for cardiac arrhythmias in horses. [ABSTRACT FROM AUTHOR]

Aim: Arteriogenesis constitutes the most efficient endogenous rescue mechanism in cases of cerebral ischaemia. The aim of this work was to investigate whether angiotensin‐converting enzyme inhibitors (ACEi) stimulates, and angiotensin II receptor type 1 blockers (ARB) inhibits cerebral collateral growth by applying a three‐vessel occlusion (3‐VO) model in rat. Methods: Cerebral collateral growth was measured post 3‐VO (1) by assessing blood flow using the cerebrovascular reserve capacity (CVRC) technique, and (2) by assessing vessel diameters in the posterior cerebral artery (PCA) via the evaluation of latex angiographies. A stimulatory effect on arteriogenesis was investigated for ACEi administration ± bradykinin receptor 1 (B1R) and 2 (B2R) blockers, and an inhibitory effect was analysed for ARB administration. Results were validated by immunohistochemical analysis and mechanistic data were collected by human umbilical vein endothelial cell (HUVEC) viability or scratch assay and monocyte (THP‐1) migration assay. Results: An inhibitory effect of ARB on arteriogenesis could not be demonstrated. However, collateral growth measurements demonstrated a significantly increased CVRC and PCA diameters in the ACEi group. ACEi stimulates cell viability and migration, which could be partially reduced by additional administration of bradykinin receptor 1 inhibitor (B1Ri). ACEi inhibits the degradation of pro‐arteriogenic bradykinin derivatives, but combined ACEi + B1Ri + B1Ri (BRB) treatment did not reverse the stimulatory effect. Yet, co‐administration of ACEi + BRB enhances arteriogenesis and cell migration. Conclusion: We demonstrate a potent stimulatory effect of ACEi on cerebral arteriogenesis in rats, presumable via B1R. However, results imply a pleiotropic and compensatory effect of ACEi on bradykinin receptor‐stimulated arteriogenesis. [ABSTRACT FROM AUTHOR]

Aims: This report reviews major laws, acts and regulations of social benefits and services for individuals with disabilities, focusing on cerebral palsy in the five Nordic countries. It summarizes the available benefits and services and the re-application process and provides comparative analyses among the countries. Methods: Published reports, articles and relevant government and municipal websites were reviewed for each respective country and used to compile an overview and comparison between the countries. Results: In the Nordic countries, there are a number of laws and regulations in place to support individuals with cerebral palsy and their families. In addition, there are numerous social benefits available for which individuals with disabilities can apply. Although there are national differences, the similarities across the five countries regarding laws, social benefits offered for individuals with cerebral palsy and the application processes are clear. However, the application processes seem cumbersome and, at times, redundant. Physicians and other healthcare specialists repeatedly need to write 'medical certificates' describing the diagnosis and its consequences for a disability that is chronic and lifelong. Conclusions: Participation in society for individuals with cerebral palsy disabilities can be enabled by social benefits. By extension, social benefits may indirectly have implications for public health in individuals with disabilities. Although the lives of individuals with cerebral palsy – as with others – can improve in certain areas, the need for social benefits will generally increase, not decrease, over time. Although it is clearly important to have checks and balances that prevent system misuse, it might be worthwhile from a cost-benefit perspective to investigate whether the current systems could be improved to better manage time and resources and avoid emotional distress by streamlining the application process. [ABSTRACT FROM AUTHOR]

Background: Radiofrequency ablation has been successfully applied to treat right atrial arrhythmias in horses. Ablation of left-sided arrhythmias requires a retrograde transarterial approach which is complicated. In human medicine, the left atrium is accessed through transseptal puncture (TSP) of the fossa ovalis (FO) using a caudal approach via the femoral vein., Objectives: To develop a zero fluoroscopy TSP technique for horses using a jugular vein (cranial) and transhepatic (caudal) approach., Study Design: In vivo experimental study., Methods: Transseptal puncture was performed in 18 horses admitted for euthanasia and donated for scientific research under general anaesthesia: using a jugular vein approach (10 horses), a transhepatic approach (2 horses) or both (6 horses). Radiofrequency energy was applied on a guidewire to perforate the FO and allow sheath advancement under intracardiac and transthoracic echocardiographic guidance. Puncture lesions were inspected post-mortem., Results: Transseptal puncture was successful in 17/18 horses, of which 15/16 jugular vein approaches and 5/8 transhepatic approaches. Failure was due to technical malfunction, inability to advance the guidewire toward the heart and inability to advance the sheath through the FO. Intracardiac echocardiography was essential to safely guide the puncture process. Atrial arrhythmias caused by the TSP occurred in 13/18 horses. Puncture lesions were found in the right atrium in the FO region, and left atrium ventral to pulmonary vein ostium III., Main Limitations: Because in several horses two approaches were tested consecutively, it cannot be excluded that the second TSP was performed at the previous puncture site. Due to the developmental nature of the study the approaches were not randomised and did not allow comparison., Conclusion: Transseptal puncture is feasible in horses using ultrasound guidance and allows for electrophysiological exploration of the left heart. Further studies are needed to evaluate post-operative follow-up., (© 2024 EVJ Ltd.)