The intrusive nature of epicardial adipose tissue as revealed by cardiac magnetic resonance

The epicardial adipose tissue (EAT) refers to the deposition of adipose tissue fully enclosed by the pericardial sac. EAT has a complex mixture of adipocytes, nervous tissue, as well as inflammatory, stromal and immune cells secreting bioactive molecules. This heterogeneous composition reveals that it is not a simply fat storage depot, but rather a biologically active organ that appears playing a “dichotomous” role, either protective or proinflammatory and proatherogenic. The cardiac magnetic resonance (CMR) allows a clear visualization of EAT using a specific pulse sequence called steady-state free precession. When abundant, the EAT assumes a pervasive presence not only covering the entire epicardial surface but also invading spaces that usually are almost virtual and separating walls that usually are so close each other to resemble a single wall. To the best of our knowledge, this aspect of cardiac anatomy has never been described before. In this pictorial review, we therefore focus our attention on certain cardiac areas in which EAT, when abundant, is particularly intrusive. In particular, we describe the presence of EAT into: (a) the interatrial groove, the atrioventricular septum, and the inferior pyramidal space, (b) the left lateral ridge, (c) the atrioventricular grooves, and (d) the transverse pericardial sinus. To confirm the reliability in depicting the EAT distribution, we present CMR images side-by-side with corresponding anatomic specimens

Electrical and Mechanical Ventricular Activation During Left Bundle Branch Block and Resynchronization

Cardiac resynchronization therapy (CRT) aims to treat selected heart failure patients suffering from conduction abnormalities with left bundle branch block (LBBB) as the culprit disease. LBBB remained largely underinvestigated until it became apparent that the amount of response to CRT was heterogeneous and that the therapy and underlying pathology were thus incompletely understood. In this review, current knowledge concerning activation in LBBB and during biventricular pacing will be explored and applied to current CRT practice, highlighting novel ways to better measure and treat the electrical substrate

The tricuspid valve

Interest in the anatomy of the tricuspid valve has increased in the past two decades with the awareness that functional tricuspid regurgitation (FTR) is not an innocuous bystander of left-side heart disease but, on the contrary, is an insidious disease progressively leading to untreatable right heart failure and eventually to death. Most cases of severe tricuspid regurgitation are functional, due to right ventricular (RV) enlargement, annular dilatation, and leaflet tethering. Commonly, RV dilatation is secondary to left-side valvular diseases (mainly mitral valve stenosis or regurgitation), heart failure, and RV volume or pressure overload. Less frequently, severe FTR is the consequence of tricuspid annular dilatation due to isolated atrial enlargement caused by atrial fibrillation. Mild tricuspid regurgitation in the setting of a structurally normal tricuspid valve is a normal echocardiographic aspect

A novel interventional guidance framework for transseptal puncture in left atrial interventions

Access to the left atrium is required for several percutaneous cardiac interventions. In these procedures, the inter-atrial septal wall is punctured using a catheter inserted in the right atrium via the venous system under image guidance. Although this approach (termed transseptal puncture - TSP) is performed daily, complications are common. Moreover, the exact location at which the septum needs to be traversed is determined entirely based on the interventionist’s experience, which is sub-optimal. In this work, we present a novel concept for the development of an interventional guidance framework for TSP. The pre-procedural planning stage is fused with 3D intra-procedural images (echocardiography) using manually defined landmarks, transferring the relevant anatomical landmarks to the interventional space and enhancing the echocardiographic images. In addition, electromagnetic sensors are attached to the surgical instruments, tracking them and allowing the inclusion of their spatial position in the enhanced intra-procedural world. Two patient-specific atrial phantom models were used to evaluate this framework. One operator performed the planning, calibrated the setup and performed the puncture. To assess the framework’s accuracy, a metallic landmark was positioned in the punctured location and compared with the ideal one. The intervention was possible in both models, but in one case positioning of the landmark failed. An error of approximately of 6 mm was registered for the successful case. Technical characteristics of the framework showed an acceptable performance, with a frame rate ~5 frames/sec. The manual calibration setup required ~60 min. This study presented a proof-of-concept for an interventional guidance framework for TSP. However, a more automated solution and further studies to assess its accuracy are required.The authors acknowledge Fundação para a Ciência e a Tecnologia (FCT), in Portugal, and the European Social Found, European Union, for funding support through the “Programa Operacional Capital Humano” (POCH) in the scope of the PhD grants SFRH/BD/95438/2013 (P. Morais) and SFRH/BD/93443/2013 (S. Queirós). This work was funded by projects NORTE-01-0145-FEDER-000013, NORTE-01- 0145-FEDER-000022 and NORTE-01-0145-FEDER-024300, supported by Northern Portugal Regional Operational Programme (Norte2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER), and has also been funded by FEDER funds, through Competitiveness Factors Operational Programme (COMPETE), and by national funds, through the FCT, under the scope of the project POCI-01-0145-FEDER-007038. The authors would like to acknowledge Walter Coudyzer and Steven Dymarkowski (Department of Radiology, UZLeuven, Leuven, Belgium) for performing the CT acquisitions. Moreover, the authors would like to thank General Electric (GE VingMed, Horten, Norway) for giving access to the 3D streaming option