Profiling Reduced Expression of Contractile and Mitochondrial mRNAs in the Human Sinoatrial Node vs. Right Atrium and Predicting Their Suppressed Expression by Transcription Factors and/or microRNAs.

(1) Background: The sinus node (SN) is the main pacemaker of the heart. It is characterized by pacemaker cells that lack mitochondria and contractile elements. We investigated the possibility that transcription factors (TFs) and microRNAs (miRs) present in the SN can regulate gene expression that affects SN morphology and function.

Anatomic obstacles in cavotricuspid isthmus detected by modified 2D transthoracic echocardiography and long-term outcomes in radiofrequency ablation of typical atrial flutter.

Background: Although radiofrequency ablation of the cavotricuspid isthmus (CTI), responsible for sustaining atrial flutter, is a highly effective procedure, in extended patients' observations following this procedure, more than every tenth becomes unsuccessful. Therefore, this study aimed to provide helpful information about the anatomy of the CTI in transthoracic echocardiography, which can aid in better planning of the CTI radiofrequency ablation in patients with typical atrial flutter.

Materials And Methods: 56 patients with typical atrial flutter after radiofrequency ablation were evaluated at the end of the 24-month observation period.

Interactive teaching of medical 3D cardiac anatomy: atrial anatomy enhanced by ECG and 3D visualization.

The most commonly applied way of teaching students to convey the foundations of human anatomy and physiology involves textbooks and lectures. This way of transmitting knowledge causes difficulties for students, especially in the context of three-dimensional imaging of organ structures, and as a consequence translates into difficulties with imagining them. Even despite the rapid uptake of knowledge dissemination provided by online materials, including courses and webinars, there is a clear need for learning programs featuring first-hand immersive experiences tailored to suit individual study paces.

Morphology of human sinoatrial node and its surrounding right atrial muscle in the global obesity pandemic-does fat matter?

Introduction: The sinus node (SN) is the main pacemaker site of the heart, located in the upper right atrium at the junction of the superior vena cava and right atrium. The precise morphology of the SN in the human heart remains relatively unclear especially the SN microscopical anatomy in the hearts of aged and obese individuals. In this study, the histology of the SN with surrounding right atrial (RA) muscle was analyzed from young non-obese, aged non-obese, aged obese and young obese individuals.

The anatomy of the atrioventricular nodal artery: A meta-analysis with implications for cardiothoracic surgery and ablation procedures.

The objective of the present meta-analysis was to evaluate recent and applicable data regarding the location and variation of the atrioventricular nodal artery (AVNA) in relation to adjacent structures. In order to minimize postoperative risks and maintain physiological anastomosis for proper cardiac function, understanding such possible variations of vascularization of the AV node is of immense importance prior to cardiothoracic surgery as well as ablations. In order to perform this meta-analysis, a systematic search was conducted in which all articles regarding, or at least mentioning, the anatomy of the AVNA was searched.

Permanent single-chamber atrial pacing: an obsolete or viable alternative to dual-chamber pacing in selected patients with sinus node disease?

Introduction: Single atrial stimulation (AAI) has been commonly used for permanent pacing in sick sinus syndrome and significant bradycardia.

Objective: The study aimed to evaluate long‑term AAI pacing and to identify timing and reasons for pacing mode change.

Patients And Methods: Retrospectively, we included 207 patients (60% women) with initial AAI pacing, who were followed‑up for an average of 12 years.

Compound motor action potentials in transient and persistent phrenic nerve injury - metanalysis.

The right phrenic nerve is vulnerable to injury (PNI) during cryoballoon ablation (CBA) isolation of the right pulmonary veins. The complication can be transient or persistent. The reported incidence of PNI fluctuates from 4.

How to write an umbrella review? A step-by-step tutorial with tips and tricks.

The number of meta-analyses (MA) and systematic reviews (SR) on various medical issues has increased during the last two decades. The MA and SR results may differ from one another due to a number of factors such as inaccurate or diverse searches through the databases, discrepancies in the extraction process or in statistical analysis, among others. Some results may even contradict one another, resulting in confusion among readers.

Radiofrequency catheter ablation of ventricular tachycardia using combined endocardial techniques in patients with structural heart disease improves procedural effectiveness and reduces arrhythmia episodes.

Background: Evidence indicates that radiofrequency catheter ablation (RFCA) of ventricular tachycardia (VT) in patients with structural heart disease (SHD) is safe and effective. However, arrhythmia recurrence is still relatively high, and the optimal procedural strategy is unclear. In clinical practice, several combinations of mapping and ablation techniques are used to improve VT ablation efficacy.

Topographical anatomy of the left ventricular summit: implications for invasive procedures.

Background: Recent clinical reports have emphasized the clinical significance of the left ventricular summit (LVS), a specific triangular epicardial area, as the source of ventricular arrhythmias where radiofrequency ablation is of great difficulty.

Materials And Methods: The macroscopic morphology of the LVS has been assessed in 80 autopsied and 48 angio-computed tomography (CT) human hearts. According to Yamada's equation, the size was calculated based on the distance to the first, most prominent septal perforator.

Prevalence of Arrhythmia in Adults after Fontan Operation.

Structural, hemodynamic, and morphological cardiac changes following Fontan operation (FO) can contribute to the development of arrhythmias and conduction disorders. Sinus node dysfunction, junction rhythms, tachyarrhythmias, and ventricular arrhythmias (VAs) are some of the commonly reported arrhythmias. Only a few studies have analyzed this condition in adults after FO.

Gross anatomic relationship between the human left atrial appendage and the left ventricular summit region: implications for catheter ablation of ventricular arrhythmias originating from the left ventricular summit.

Purpose: The left ventricular summit (LVS) is a source of difficult-to-treat arrhythmias because of anatomical limitations. The aim of this study was to perform detailed research of the left atrial appendage (LAA) anatomy of cadaveric hearts to analyze their complex anatomy and coverage of the LVS.

Methods And Results: Eighty human formalin fixed hearts (mean age 44.

Contact Force-Sensing versus Standard Catheters in Non-Fluoroscopic Radiofrequency Catheter Ablation of Idiopathic Outflow Tract Ventricular Arrhythmias.

Background: Adequate contact between the catheter tip and tissue is important for optimal lesion formation and, in some procedures, it has been associated with improved effectiveness and safety. We evaluated the potential benefits of contact force-sensing (CFS) catheters during non-fluoroscopic radiofrequency catheter ablation (NF-RFCA) of idiopathic ventricular arrhythmias (VAs) originating from outflow tracts (OTs).

Methods: A group of 102 patients who underwent NF-RFCA (CARTO, Biosense Webster Inc.

Left Ventricular Summit-Concept, Anatomical Structure and Clinical Significance.

The left ventricular summit (LVS) is a triangular area located at the most superior portion of the left epicardial ventricular region, surrounded by the two branches of the left coronary artery: the left anterior interventricular artery and the left circumflex artery. The triangle is bounded by the apex, septal and mitral margins and base. This review aims to provide a systematic and comprehensive anatomical description and proper terminology in the LVS region that may facilitate exchanging information among anatomists and electrophysiologists, increasing knowledge of this cardiac region.

Further insights into the molecular complexity of the human sinus node - The role of 'novel' transcription factors and microRNAs.

Research Purpose: The sinus node (SN) is the heart's primary pacemaker. Key ion channels (mainly the funny channel, HCN4) and Ca-handling proteins in the SN are responsible for its function. Transcription factors (TFs) regulate gene expression through inhibition or activation and microRNAs (miRs) do this through inhibition.

Non-fluoroscopic radiofrequency catheter ablation of right- and left-sided ventricular arrhythmias.

Introduction: Radiofrequency catheter ablation (RFCA) is an important method of treatment of ventricular arrhythmias (VAs). In the majority of RFCA, fluoroscopy is used, exposing patients and medical staff to all related side effects. Current experience of non-fluoroscopic (NF)-RFCA in VAs from the left side is limited.

Tracing the Right Phrenic Nerve - A Systematic Review and Meta-Analysis.

Background: The Right phrenic nerve (RPN) is vulnerable to injury during the isolation of the right pulmonary veins (RPV). The study aimed to provide a comprehensive meta-analysis of the overall prevalence of right phrenic nerve injury (RPNI), its course and its association with the superior and inferior pulmonary veins.

Methods: Through December 2017, a database search was performed on PubMed, Science Direct, EMBASE, SciELO, and Web of Science.

Applicability of computed tomography preoperative assessment of the LAA in LV summit ablations.

Purpose: Ventricular arrhythmias originating from the left ventricular summit (LVS) may present with challenges for catheter ablation. Recently, the left atrial appendage (LAA) became a new vantage point for mapping and ablating arrhythmias from that region, but data of possible usefulness is limited.

Methods: From September to December 2019, we retrospectively analyzed 48 consecutive patient hearts (20 male; mean age 57.

[Atrial flutter in cardiology practice].

Atrial flutter (AFL) is one of the most common arrhythmias present in clinical practice, both for the GPs and cardiologist practice. After atrial fibrillation (AF) is second the most common supraventricular arrhythmia. This usually occurs along the cavo-tricuspid isthmus of the right atrium though atrial flutter can originate from the left atrium as well.