Brugada Syndrome: From Molecular Mechanisms and Genetics to Risk Stratification

Brugada syndrome (BrS) is a rare hereditary arrhythmia disorder, with a distinctive ECG pattern, correlated with an increased risk of ventricular arrhythmias and sudden cardiac death (SCD) in young adults. BrS is a complex entity in terms of mechanisms, genetics, diagnosis, arrhythmia risk stratification, and management. The main electrophysiological mechanism of BrS requires further research, with prevailing theories centered on aberrant repolarization, depolarization, and current-load match. Computational modelling, pre-clinical, and clinical research show that BrS molecular anomalies result in excitation wavelength (k) modifications, which eventually increase the risk of arrhythmia. Although a mutation in the SCN5A (Sodium Voltage-Gated Channel Alpha Subunit 5) gene was first reported almost two decades ago, BrS is still currently regarded as a Mendelian condition inherited in an autosomal dominant manner with incomplete penetrance, despite the recent developments in the field of genetics and the latest hypothesis of additional inheritance pathways proposing a more complex mode of inheritance. In spite of the extensive use of the next-generation sequencing (NGS) technique with high coverage, genetics remains unexplained in a number of clinically confirmed cases. Except for the SCN5A which encodes the cardiac sodium channel NaV1.5, susceptibility genes remain mostly unidentified. The predominance of cardiac transcription factor loci suggests that transcriptional regulation is essential to the Brugada syndrome's pathogenesis. It appears that BrS is a multifactorial disease, which is influenced by several loci, each of which is affected by the environment. The primary challenge in individuals with a BrS type 1 ECG is to identify those who are at risk for sudden death, researchers propose the use of a multiparametric clinical and instrumental strategy for risk stratification. The aim of this review is to summarize the latest findings addressing the genetic architecture of BrS and to provide novel perspectives into its molecular underpinnings and novel models of risk stratification.

Modern Approaches for the Treatment of Heart Failure: Recent Advances and Future Perspectives

Heart failure (HF) is a progressively deteriorating medical condition that significantly reduces both the patients’ life expectancy and quality of life. Even though real progress was made in the past decades in the discovery of novel pharmacological treatments for HF, the prevention of premature deaths has only been marginally alleviated. Despite the availability of a plethora of pharmaceutical approaches, proper management of HF is still challenging. Thus, a myriad of experimental and clinical studies focusing on the discovery of new and provocative underlying mechanisms of HF physiopathology pave the way for the development of novel HF therapeutic approaches. Furthermore, recent technological advances made possible the development of various interventional techniques and device-based approaches for the treatment of HF. Since many of these modern approaches interfere with various well-known pathological mechanisms in HF, they have a real ability to complement and or increase the efficiency of existing medications and thus improve the prognosis and survival rate of HF patients. Their promising and encouraging results reported to date compel the extension of heart failure treatment beyond the classical view. The aim of this review was to summarize modern approaches, new perspectives, and future directions for the treatment of HF.

The Advantages of New Multimodality Imaging in Choosing the Optimal Management Strategy for Patients with Hypertrophic Cardiomyopathy

In recent years, significant advances have been made in the diagnosis and therapeutic management of hypertrophic cardiomyopathy (HCM) patients, which has led to an important improvement in their longevity and quality of life. The use of multimodality imaging has an essential role in the diagnosis, assessing the regional distribution and severity of the disease, with important prognostic implications. At the same time, imaging contributes to the identification of optimal treatment for patients with hypertrophic cardiomyopathy, whether it is pharmaceutical, interventional or surgical treatment. Novel pharmacotherapies (like myosin inhibitors), minimally invasive procedures (such as transcatheter mitral valve repair, high-intensity focused ultrasound or radiofrequency ablation) and gene-directed approaches, may soon become alternatives for HCM patients. However, there are only few data on the early diagnosis of patients with HCM, in order to initiate treatment as soon as possible, to reduce the risk of sudden cardiac death (SCD). The aim of our review is to highlight the advantages of contemporary imaging in choosing the optimal management strategies for HCM patients, considering the novel therapies which are currently applied or studied for these patients.

Impact of HVAC-Systems on the Dispersion of Infectious Aerosols in a Cardiac Intensive Care Unit

At the end of 2019, a variation of a coronavirus, named SARS-CoV-2, has been identified as being responsible for a respiratory illness disease (COVID-19). Since ventilation is an important factor that influences airborne transmission, we proposed to study the impact of heating, ventilation and air-conditioning (HVAC) with a variable air volume (VAV) primary air system, on the dispersion of infectious aerosols, in a cardiac intensive care unit, using a transient simulation with computational fluid dynamics (CFD), based on the finite element method (FEM). We analyzed three scenarios that followed the dispersion of pathogen carrying expiratory droplets particles from coughing, from patients possibly infected with COVID-19, depending on the location of the patients in the intensive care unit. Our study provides the mechanism for spread of infectious aerosols, and possibly of COVID-19 infection, by air conditioning systems and also highlights important recommendations for disease control and optimization of ventilation in intensive care units, by increasing the use of outdoor air and the rate of air change, decreasing the recirculation of air and using high-efficiency particulate air (HEPA) filters. The CFD-FEM simulation approach that was applied in our study could also be extended to other targets, such as public transport, theaters, philharmonics and amphitheaters from educational units.

CORRELATIONS BETWEEN ARTERIAL HYPERTENSION INDUCED BY ANGIOTENSIN II AND SYSTEMIC INFLAMMATION IN RAT

Angiotensin II has articularly shown to play a key role in the regulation of inflammatory processes in hypertension.

AIM

The present study aims to correlate the angiotensin II-induced hypertension 4th systemic inflammation.

MATERIAL AND METHODS

We conducted an experimental study on Wistar male rats who received Ang II via subcutaneous miniosmotic pumps for 2 weeks. Rats were exposed to a 12h light /12h dark cycle. Sham rats were used as control. Systolic load pressure measurements and a flow cytometric analysis of lymphocyte surface markers were performed. After 14 days, the animals were euthanized under anesthesia with ylazine/ketaniine.

RESULTS

Systolic BP progressively and significantly increased in rats 4th Ang II chronic infusion. We observed a statistical significant difference (p = 0.00001), in terms of T lymphocytes percentage between control rats plasma and Ang H treated rats lasma, in 14 days.

CONCLUSIONS

Angiotensin II is an important mediator of hypertension and directly promotes inflammation by noticeably increasing the quantity of T cells in kidney tissue.

Morphological changes in membranoproliferative glomerulonephritis - a quantitative approach

Our study aimed to investigate the quantitative profile of the renal corpuscle components in membranoproliferative glomerulinephritis (MPGN). We have analyzed digital color images corresponding to relevant microscopic fields from renal biopsies (10 cases type I MPGN and 10 cases type II MPGN). A computerized morphometric algorithm was designed and applied in both red-green-blue (RGB) and hue-lightness-saturation (HLS) color spaces, allowing the automated measurement of areas for the following morphological characteristics of the renal corpuscles (RCs): glomerulus, Bowman space, cells, mesangial matrix and glomerular basement membranes, and capillaries. Student's t-test comparatively applied between the numerical data obtained for the measured morphological characteristics, for each individual color space, showed significant differences between type I MPGN and type II MPGN for Bowman space area (p=0.006) and for mesangial matrix and glomerular basement membranes area - exclusively in RGB color space (p=0.013). We have also demonstrated larger RCs and glomerular size in type II MPGN, comparative to those in type I MPGN. Consequently, we assume that the morphometrical characterization of RCs histological components could be used as an additional criterion not only in the diagnosis of MPGNs, but also in the stratification of evolution and prognosis of patients diagnosed with type I and II MNGN, respectively.