Search Results (251)

What is known today as the triangle of Koch (the triangular locus of the atrioventricular node, TLAVN) is bordered by the fibrous attachment of the septal cusp of tricuspid valve, the opening of the coronary sinus and tendon of valve of inferior vena cava (TIVCV). This is a concept developed cumulatively by several exceptional anatomists. The literature was reviewed with a focus on the discovery of the atrioventricular node by Sunao Tawara (January 1906), its previous announcement by Tawara’s mentor Ludwig Aschoff (1905), and the contributions of the authors who described the other components of the triangular locus. Francesco Todaro discovered the TIVCV (1865); Tawara described the atrioventricular node and its relationship with the fibrous attachment of the septal cusp of tricuspid valve and the opening of the coronary sinus. The first description of assembling all components was provided by Arthur Keith (March 1906). Keith was also the first to consider the triangular locus as a useful landmark for identifying the atrial structures of the conduction system discovered by Tawara and Wilhelm His Jr. (1893). Julius Tandler named the TLAVN as Koch’s triangle (1913). Keith’s contributions to this topic have been particularly overlooked. The “triangular locus of the atrioventricular node” or “triangle of the atrioventricular node” are more instructive and impartial names. Full article

Background: Chest X-ray (CXR) is widely used for the assessment of thoracic diseases, yet automated multi-label interpretation remains challenging due to subtle visual patterns, overlapping anatomical structures, and frequent co-occurrence of abnormalities. While recent deep learning models have shown strong performance, limitations in interpretability, anatomical awareness, and robustness continue to hinder their clinical adoption. Methods: The proposed framework employs a hybrid ConvNeXtV2–Vision Transformer (ViT) architecture that combines convolutional feature extraction for capturing fine-grained local patterns with transformer-based global reasoning to model long-range contextual dependencies. The model is trained exclusively using image-level annotations. In addition to classification, three complementary post hoc components are integrated to enhance model trust and interpretability. A segmentation-aware Gradient-weighted class activation mapping (Grad-CAM) module leverages CheXmask lung and heart segmentations to highlight anatomically relevant regions and quantify predictive evidence inside and outside the lungs. An ontology-driven neuro-symbolic reasoning layer translates Grad-CAM activations into structured, rule-based explanations aligned with clinical concepts such as “basal effusion” and “enlarged cardiac silhouette”. Furthermore, a lightweight out-of-distribution (OOD) detection module based on confidence scores, energy scores, and Mahalanobis distance scores is employed to identify inputs that deviate from the training distribution. Results: On the VinBigData test set, the model achieved a macro-AUROC of 0.9525 and a Micro AUROC of 0.9777 when trained solely with image-level annotations. External evaluation further demonstrated strong generalisation, yielding macro-AUROC scores of 0.9106 on NIH ChestXray14 and 0.8487 on CheXpert (frontal views). Both Grad-CAM visualisations and ontology-based reasoning remained coherent on unseen data, while the OOD module successfully flagged non-thoracic images. Conclusions: Overall, the proposed approach demonstrates that hybrid convolutional neural network (CNN)–vision transformer (ViT) architectures, combined with anatomy-aware explainability and symbolic reasoning, can support automated chest X-ray diagnosis in a manner that is accurate, transparent, and safety-aware. Full article

Over the past three decades, cardiac surgery has undergone a deep transformation, shifting from full median sternotomy to minimally invasive (MICS) and micro-invasive techniques. These approaches aim to achieve equivalent therapeutic outcomes while reducing surgical trauma, postoperative pain, hospitalization time, and healthcare costs. Minimally invasive strategies are now widely applied to aortic and mitral valve surgery, coronary artery bypass grafting, atrial fibrillation ablation, and combined procedures. Key advancements such as sutureless prostheses, video- and robotic-assisted systems, and enhanced imaging technologies have improved surgical precision and clinical outcomes while promoting faster recovery and superior cosmetic results. Evidence from randomized trials and observational studies demonstrates that MICS provides mortality and morbidity rates comparable to conventional surgery, with additional benefits in high-risk, elderly, and frail patients. Micro-invasive transcatheter interventions, particularly transcatheter aortic valve implantation (TAVI) and transcatheter mitral repair or replacement, have further expanded therapeutic options for patients unsuitable for open-heart surgery. Their success has fostered debate not between conventional and minimally invasive surgery, but between minimally invasive and micro-invasive approaches. Hybrid procedures—combining surgical and percutaneous techniques—exemplify a multidisciplinary evolution aimed at tailoring treatment to patient-specific anatomy, comorbidities, and risk profiles. Despite clear advantages, these techniques present challenges, including a steep learning curve, increased procedural costs, and the requirement for specialized equipment and institutional expertise. Optimal patient selection based on clinical risk assessment and advanced imaging remains essential. Future directions include refinement of robotic platforms, artificial intelligence-based decision support, miniaturization of instruments, and broader validation of emerging technologies in younger and low-risk populations. Minimally and micro-invasive cardiac surgery represent a paradigm shift toward patient-centered care, offering reduced physiological burden, improved functional recovery, and long-term outcomes comparable to conventional techniques. As innovation continues, these approaches are poised to become integral to modern cardiac surgical practice. Full article

Mitral regurgitation (MR) is one of the most prevalent valvular disorders worldwide, with a growing burden driven by population aging and improved diagnostic capabilities. Understanding the mechanism of MR, whether primary, due to intrinsic valve abnormalities, or secondary, resulting from atrial or ventricular remodeling, is essential for optimal management. Echocardiography, particularly advanced modalities such as three-dimensional imaging and strain analysis, plays a central role in this process. It allows accurate quantification of MR severity, detailed characterization of valve and ventricular anatomy, and assessment of remodeling, all of which are critical for determining the optimal timing for intervention. Beyond diagnosis, echocardiography is indispensable in guiding therapy selection: it informs surgical planning by defining leaflet pathology for repair versus replacement strategies, and directs transcatheter interventions by guiding interatrial septal puncture, catheter orientation, and device deployment in real time. While surgery remains the gold standard for primary MR, transcatheter approaches including edge-to-edge repair and emerging mitral valve replacement are increasingly relevant, particularly in patients at high surgical risk or with complex anatomy. This review emphasizes the pivotal role of echocardiography in the pre-procedural assessment of MR, highlighting its ability to integrate anatomical, functional, and hemodynamic information to guide patient-tailored therapeutic strategies and optimize outcomes within a Heart Team framework. Full article

Severe aortic stenosis represents a significant prognostic burden, particularly in symptomatic patients. The advent of transcatheter aortic valve replacement (TAVR) has revolutionized the treatment of patients previously considered ineligible for surgical aortic valve replacement (SAVR). TAVR provides a relatively safe intervention that leads to improvements in survival, symptoms, and functional status within months of implantation. A major complication following TAVR is the occurrence of paravalvular leaks (PVLs), which have been associated with increased mortality and higher rates of heart failure-related hospitalizations. PVLs refer to abnormal blood flow between the implanted valve and the aortic wall, which can compromise the functionality of the device. Careful pre-procedural planning enables the identification of patients at higher risk for PVL development. Although the incidence of PVLs has decreased with the introduction of newer-generation transcatheter valves, the condition remains clinically relevant. Due to the complex anatomy of the aortic valve apparatus and interference from the prosthetic frame, accurate evaluation of PVLs requires a multimodal diagnostic approach. Current evidence on PVL management is limited. In most cases, a conservative approach is adopted, while interventional strategies (such as pre- and post-dilatation, percutaneous PVL closure, and TAVR-in-TAVR) are reserved for selected patients. We performed a systematic literature review to summarize the incidence, predictors, diagnostic techniques, and management strategies of PVLs following TAVR. Full article

Continuous bladder volume monitoring in a wearable format can improve outcomes for patients with bladder dysfunction, heart failure, and other conditions requiring precise fluid management. Bioimpedance-based methods offer a promising, noninvasive solution; however, the influence of patient-specific anatomy, particularly waist circumference and subcutaneous fat thickness, remains poorly characterized. In this study, we use in silico finite element modeling to quantify how these anatomical factors affect two key bioimpedance metrics: voltage change ($\Delta V$) and voltage change ratio (VCR). Comprehensive simulations were performed across 15 virtual anatomies, generating a reference dataset for guiding future analog front-end and algorithm designs. We further compared generalized volume estimation models against conventional patient-specific void regression approaches. With appropriate input scaling, the generalized models achieved performance within 10% of patient-specific calibrations and, in some cases, surpassed them. Certain configurations reduced mean average error (MAE) by more than 20% relative to individualized models, potentially enabling a streamlined setup without the need for laborious ground-truth acquisition such as voided volume collection. These results demonstrate that incorporating simple anatomical scaling can yield robust, generalizable bladder volume estimation models suitable for wearable systems across diverse patient populations. Full article

Objective: Prosthesis–patient mismatch (PPM) occurs after aortic valve replacement (AVR) when the effective orifice area of the implanted prosthetic valve is small relative to the patient’s body surface area. Beyond simply elevating transvalvular gradient, PPM profoundly affects cardiac remodeling, coronary physiology, and ultimately patient survival. This comprehensive review synthesizes current evidence regarding PPM pathophysiology, clinical consequences, and therapeutic strategies. Methods: We conducted a narrative review of PPM in surgical (SAVR) and transcatheter (TAVR) aortic valve replacement. PubMed and Embase were systematically searched using terms related to AVR and PPM and reference lists of key studies and reviews were screened. Studies addressing PPM prevalence, hemodynamic impact, clinical outcomes, and mitigation strategies were included. Results: PPM, defined as an iEOA ≤ 0.85 cm²/m² (moderate) or ≤0.65 cm²/m² (severe), demonstrates variable prevalence across studies, typically ranging from 5 to 30% after SAVR and 2–35% after TAVR. It is associated with increased transvalvular gradients, reduced left ventricular mass regression, persistent coronary flow abnormalities, higher rates of heart failure, and both early and late mortality. Supra-annular self-expanding transcatheter aortic valve replacement (TAVR) devices and newer generation stentless or bovine pericardial surgical valves exhibit lower PPM rates than older stented or porcine valves. Valve-in-valve (ViV) TAVR and bioprosthetic valve fracture (BVF) can improve outcomes in failed surgical valves but are less effective in small annuli. TAVR-in-TAVR procedures are limited by anatomic and technical constraints, especially in maintaining coronary access and minimizing residual gradients. Conclusions: PPM remains a common and clinically consequential complication of AVR that compromises long-term outcomes. It is largely preventable through accurate preoperative imaging, valve sizing, and consideration of annular enlargement. Optimal outcomes require matching valve characteristics to individual patient anatomy and physiology. In an era of expanding TAVR use, preventing PPM during the index procedure is critical to optimizing survival and preserving future reintervention options. Full article

Mitral annular calcification makes conventional mitral valve surgery extremely challenging and has led to growing interest in less invasive alternatives such as transcatheter mitral valve replacement. Alongside percutaneous approaches, some centers have explored open transatrial implantation of transcatheter heart valves in patients with heavily calcified annuli. This systematic review examines the current evidence on this hybrid “valve-in-MAC” technique, tracing its clinical evolution, technological refinements, patient outcomes, and ongoing debates. Key themes emerging from the literature include the adaptation of existing balloon-expandable and mitral-specific devices to the complex anatomy of calcified mitral annuli, the open transatrial approach as a safer alternative to extensive surgical debridement, and advances in imaging and device design aimed at reducing left ventricular outflow tract obstruction and paravalvular leak. Persistent uncertainties remain, particularly regarding patient selection, long-term valve performance, and comparisons with conventional surgical repair or replacement. Although open transatrial implantation appears technically feasible and provides favorable hemodynamic results compared with fully percutaneous procedures, reported 30-day mortality remains high (approximately 19–27%). This reflects the advanced age, frailty, and multiple comorbidities typical of this patient group rather than procedural shortcomings. Current evidence is limited, with few comparative studies and little data on valve durability. Future work should prioritize multicenter prospective registries and well-designed comparative studies to better define the role of this emerging salvage strategy. Full article

Background. Accurate anatomical assessment is essential for pre-procedural planning in structural heart disease. Advanced 3D imaging could offer improved visualization for more accurate reconstruction. We assessed the performance of a novel immersive 3D virtual reality (VEA) for the pre-procedural planning of transcatheter aortic valve implantation (TAVI) candidates. Methods. Measurement of cardiac-gated contrast-enhanced computed tomography (CT) scans was performed with the novel VEA and established tools: 3Mensio and Horos. Results. 50 consecutive patients were included. Annular and LVOT measurements obtained with VEA were strongly correlated with those derived from standard CT analysis. The intraclass correlation coefficient (ICC) confirmed excellent consistency for annular measurements (ICC = 0.93), while the concordance correlation coefficient indicated very good overall agreement (CCC = 0.83, 95% CI 0.73–0.90). Similarly, LVOT measurements obtained with VEA showed strong correlation with CT values, with good consistency (ICC = 0.90) and good overall agreement (CCC = 0.77, 95% CI 0.64–0.86). VEA-based planning improved prosthesis size selection accuracy, achieving higher concordance with implanted valves and a significant net reclassification gain over conventional CT. Conclusions. Given the increasing use of advanced 3D cardiac imaging technologies, understanding their diagnostic accuracy to guide pre-procedural planning of TAVI is paramount. In our study, VEA provided reliable assessment of aortic root anatomy for TAVI planning. This novel 3D software provides accurate, patient-specific reconstructions of the aortic root and surrounding structures that may optimize valve sizing, improve procedural safety and enhance procedural outcomes. This provides a rationale for future studies to assess the procedural benefit derived from a three-dimensional assessment of the aortic valve geometry. Full article

Pacing in complex congenital heart disease can be difficult and with significant drawbacks due to issues with infection and long-term leads within the vasculature. Leadless pacemakers have emerged as a new technology with a strong safety and efficacy record in normal cardiac anatomy. Here, we review the current available technology, current evidence in complex congenital pacing and how leadless pacemakers may be used in complex congenital heart disease. Full article

Tricuspid atresia (TA) is a cyanotic congenital heart defect defined by agenesis of the tricuspid valve and resultant right ventricular hypoplasia, representing 1.4–2.9% of congenital heart disease. Survival depends on interatrial and interventricular shunts that permit systemic and pulmonary blood flow, with staged surgical palliation culminating in the Fontan procedure. While surgical advances have improved long-term outcomes, Fontan circulation remains a delicate physiology characterized by preload dependence, elevated pulmonary vascular resistance, chronic venous hypertension, and a prothrombotic state. These features predispose patients to arrhythmias, lymphatic complications, hepatic congestion, and progressive circulatory failure. For anesthesiologists, perioperative management of TA and Fontan patients is uniquely complex. Anesthetic considerations include meticulous preload optimization, modulation of systemic and pulmonary vascular resistance, and ventilatory strategies that minimize adverse effects on venous return. Additional challenges include the high risk of air embolism, individualized anticoagulation needs, and hemodynamic sensitivity to patient positioning. Preoperative evaluation with echocardiography and electrocardiography provides critical insight into anatomy and physiology, while intraoperative planning must emphasize goal-directed fluid management, careful agent selection, and tailored ventilation. Postoperatively, vigilant monitoring, effective pain control, and prevention of complications are essential. This review synthesizes classification systems, pathophysiology, and the evolution of surgical palliation, while emphasizing anesthetic principles for the perioperative care of patients with TA and Fontan circulation. As survival improves and the population of Fontan patients expands, a nuanced understanding of this physiology is essential for optimizing outcomes across cardiac and non-cardiac surgical settings. Full article

Background: Since the study of Lev and Thaemert in 1973, little has been published concerning the overall arrangement of the murine conduction tissues, in particular with relation to gross anatomical landmarks. We recently emphasised the potential value of the mouse as an experimental animal in determining the role, if any, of the superior septal pathways in ventricular activation, comparing the findings to the arrangement in the human heart. Our previous study, however, was confined to the atrioventricular conduction axis. In the light of recent controversies regarding atrial conduction, we have now extended our study to evaluate the overall arrangement of the conduction tissues in the murine heart. Methods: We have re-examined serially sectioned histological datasets previously prepared from adult mouse hearts, incorporating new datasets to permit assessment in the three orthogonal planes, correlating the histological findings with the gross anatomy as revealed in episcopic datasets prepared from late foetal and neonatal mice. Results: The overall arrangement of the conduction tissues is comparable with the human arrangement, but with subtle differences. The sinus node straddles the superior cavoatrial junction, rather than being embedded within the terminal groove. Conduction from the node to the atrial walls is through working atrial myocardium. The atrioventricular conduction axis, as we have recently emphasised, is much more comparable, in particular with presence of well-formed nodo-ventricular and fasciculo-ventricular pathways. In many of the hearts it is also possible to recognise a well-formed retro-aortic node. Conclusions: Despite the differences in the arrangement of the sinus node, mouse is an ideal model for further investigations of cardiac conduction, in particular to clarify the potential roles of the superior septal pathways and the retro-aortic node. Full article

Background: Advances in diagnosis and treatment have led to a growing population of adults with congenital heart disease (ACHD). Despite increasing life expectancy, their clinical needs—especially in older age—remain poorly defined. Cardiac and non-cardiac comorbidities are prevalent, and emerging evidence suggests accelerated biological aging compared to the general population. However, data on older patients and geriatric patients with CHD are limited. Objectives: This study aimed to characterize patients with CHD aged ≥50 years, focusing on functional status, comorbidities, sex-specific differences, and therapeutic patterns. Methods: The PATHFINDER-CHD Registry is a prospective, observational, multicenter registry enrolling patients with CHD with manifest heart failure (HF), HF history, or high HF risk. Data include anatomy, prior treatments, comorbidities, and medication use. Results: Among 1935 patients, 297 were ≥50 years old. Most had acyanotic CHD (62%); Tetralogy of Fallot (21%) was the most frequent diagnosis. A morphologic right systemic ventricle was present in 12%, and 5% had univentricular hearts. HF was manifest in 21%; 44% were classified as ACC/AHA stage B, 51% as stage C, yet 77% were in Perloff class I/II. Common cardiovascular comorbidities included aortopathy (55%), hypertension (37%), and arrhythmia (33%). Non-cardiac comorbidities included thyroid dysfunction (25%), renal impairment (18%), and neurological disease (13%). Sex-specific differences were observed. Despite HF burden, SGLT2 inhibitors and ARNIs were used in only 17% and 8.4%, respectively. Conclusions: Older patients with CHD represent a clinically complex cohort with high comorbidity burden. The findings support the concept of accelerated aging and emphasize the need for tailored interdisciplinary care strategies. Full article

Aortic coarctation (CoA) is a congenital vascular anomaly characterized by luminal narrowing of the aorta, representing approximately 5–8% of all congenital heart defects, and is frequently associated with a bicuspid aortic valve and additional vascular malformations. The clinical spectrum is broad, ranging from severe neonatal heart failure to asymptomatic systemic hypertension in adulthood, with the severity of presentation directly influencing the timing of diagnosis and therapeutic intervention. Over recent decades, management strategies have transitioned from conventional surgical techniques—such as end-to-end anastomosis, subclavian flap aortoplasty, and patch augmentation—to endovascular modalities including balloon angioplasty and stent implantation, with covered stents now constituting the preferred approach in most cases. Nonetheless, late complications remain clinically significant. Post-coarctation aneurysms (pCoAA), particularly following patch aortoplasty, have been reported in up to 50% of patients and necessitate lifelong imaging surveillance. Re-coarctation persists as a therapeutic challenge, especially in neonates, with recurrence risk influenced by anatomical factors and the initial repair method. Optimal outcomes require an individualized, anatomy-tailored approach that judiciously integrates surgical, endovascular, and hybrid techniques. Lifelong surveillance remains essential to mitigate long-term risks, including systemic hypertension, aneurysm formation, and the need for re-intervention. Full article

Background/Objectives: Children with single left ventricle (SLV) anatomy following Fontan palliation are at high risk for subclinical ventricular dysfunction, which may not be detected by conventional echocardiographic measures. Our objectives are as follows: (1) to assess myocardial and atrial strain profiles in pediatric Fontan patients with SLV using 2-dimensional speckle-tracking echocardiography (2D-STE), (2) to compare these findings with a healthy control group, (3) to investigate correlations with conventional echocardiographic and functional parameters. Methods: A single-center study of 66 pediatric patients, who underwent echocardiographic evaluation and a 6 min walk test (6 MWT). Conventional, 3D, and strain-based echocardiographic parameters were compared between groups. Correlations with clinical and functional indices were assessed using ANCOVA, analysis, generalized additive models, and Pearson’s correlation coefficient. Results: Fontan patients showed significantly reduced 6 MWT distances compared to controls (mean difference: 201.6 m, p < 0.0001). Post-test heart rate (HR) and oxygen saturation were significantly impaired (HR: 104.6 vs. 100.8 bpm, p = 0.0012; SaO₂: 90.3% vs. 99.8%, p < 0.0001). Fontan patients showed statistically significant differences in nearly all the 2D parameters. Three-dimensional echocardiography revealed significantly lower left ventricular (LV) ejection fraction (p = 0.0020), higher end-diastolic (p = 0.0275) and end-systolic volumes (p = 0.0125) in the study group. Global longitudinal strain (LV_GLS) was reduced in Fontan patients compared to controls (p < 0.0001), with significant differences across nearly all LV segments. Left atrial (LA) reservoir and conduit strain were markedly decreased, while contractile strain remained similar. LV_GLS was negatively correlated with IVCT (r = −0.50, p = 0.0175). The LA reservoir strain (LASr_AC) significantly correlated with MAPSE (r = 0.43, p = 0.0461). Conclusions: In pediatric Fontan patients, myocardial and atrial strain imaging reveals subclinical dysfunction despite preserved conventional ejection fraction. Full article