Clinical and Laboratory Data Up on Hospital Admission are Predictors of New-Onset Atrial Fibrillation in Patients Hospitalized Due to COVID-19 Pneumonia.

Background: New-onset atrial fibrillation (NOAF) occurs in patients hospitalized due to COVID-19. It is still unknown whether clinical and laboratory data assessed upon hospital admission have predictive value for NOAF.

Objectives: To analyze, upon hospital admission, variables with predictive potential for the occurrence of NOAF in patients with COVID-19 pneumonia.

Predictive Model of All-Cause Death in Patients with Heart Failure using Heart Rate Variability.

Background: Central Illustration : Predictive Model of All-Cause Death in Patients with Heart Failure using Heart Rate Variability.

Background: Short and long-duration heart rate variability (HRV) data from Holter monitoring could identify predictors of all-cause death in heart failure (HF) patients.

Objectives: To build a predictive model of all-cause death in patients with HF using HRV.

Experience in a Brazilian Center with Cryoablation for Electric Isolation of the Pulmonary Veins in Paroxysmal and Persistent Atrial Fibrillation - Preliminary Results in Brazil.

Background: Electrical isolation of the pulmonary veins is recognized as the cornerstone of non-pharmacological treatment of Atrial Fibrillation (AF), and therefore, has been recommended as the first step in AF ablation according to all guidelines. Even though the cryoballoon technology is widely used in North America and Europe, this experience is still incipient in many developing countries such as Brazil.

Objective: To evaluate initial results regarding success and safety of the new technology in patients with persistent and paroxysmal AF.

Assessing Dynamic Atrioventricular Conduction Time to RR-interval Coupling in Athletes and Sedentary Subjects.

Background Atrioventricular conduction time ( AVCT ) is influenced by autonomic input and subject to physiological remodeling. Objective To evaluate beat-by-beat AVCT and RR-interval variability in athletes and healthy sedentary subjects. Methods Twenty adults, including 10 healthy sedentary (Controls) and 10 elite long-distance runners (Athletes), age, weight and height-adjusted, underwent maximal metabolic equivalent (MET) assessment, and 15-min supine resting ECG recording seven days later.

Accuracy of the WHO's body mass index cut-off points to measure gender- and age-specific obesity in middle-aged adults living in the city of Rio de Janeiro, Brazil.

Introduction: Obesity is defined by the World Health Organization (WHO) as a disease characterized by the excessive accumulation of body fat. Obesity is considered a public health problem, leading to serious social, psychological and physical problems. However, the appropriate cut-off point of body mass index (BMI) based on body fat percentage (BF%) for classifying an individual as obese in middle-aged adults living in Rio de Janeiro remains unclear.

Prognostic Value of a New Marker of Ventricular Repolarization in Cirrhotic Patients.

Background: There is still debate about the relationship between changes in ventricular repolarization on the surface electrocardiogram and cirrhosis severity.

Objective: To study the relationship between variables related to ventricular repolarization and the clinical severity of the cirrhotic disease.

Methods: We selected 79 individuals with hepatic cirrhosis, classified according to the Child-Pugh-Turcotte criteria (Child A, B, and C).

Assessment of Autonomic Function by Phase Rectification of RRInterval Histogram Analysis in Chagas Disease.

Background: In chronic Chagas disease (ChD), impairment of cardiac autonomic function bears prognostic implications. Phase‑rectification of RR-interval series isolates the sympathetic, acceleration phase (AC) and parasympathetic, deceleration phase (DC) influences on cardiac autonomic modulation.

Objective: This study investigated heart rate variability (HRV) as a function of RR-interval to assess autonomic function in healthy and ChD subjects.

Refining the deceleration capacity index in phase-rectified signal averaging to assess physical conditioning level.

Background: Deceleration capacity (DC) of heart rate is a measure of cardiac vagal modulation. This study introduced a DC adaptation (Modified Index) that measured the velocity of change in the phase-rectified signal averaging curve, and assessed its ability to discriminate athletes from controls.

Materials And Methods: The Modified Index was compared to Standard DC approach in a prospective case-control study.

Effects of age and aerobic fitness on heart rate recovery in adult men.

Background: Physiological aging leads to cardiac autonomic dysfunction, which is associated with the onset and worsening of cardiovascular disease and an increased risk of death. Currently, physical exercise is considered a cardioprotective strategy and more research is needed on its benefit on cardiac autonomic function.

Objective: To evaluate the autonomic control of heart rate in healthy young and middle-aged volunteers with different levels of aerobic fitness.

Influence of fetal respiratory movements on left atrial functional status.

Objective: Because fetal respiratory movements increase left ventricular compliance, we hypothesized that the left atrial shortening fraction increases during fetal respiratory motions.

Methods: A group of 26 normal fetuses with gestational ages between 28 and 38 weeks were assessed in a prospective cross-sectional study. Left atrial telesystolic and presystolic diameters were measured during apnea and after five consecutive respiratory movements.

Comments on the article by Ribeiro et al. 'Enhanced parasympathetic activity in Chagas' disease still stands in need of proof': definitions and biases.

It has been hypothesized that impaired cardiac autonomic function in chagasic subject carriers of anti-muscarinic type 2 antibodies (Anti-M2) is a consequence of tonic stimulation (enhancement) of M2 receptors, thus damping high frequency spontaneous heart rate fluctuations. However, expected reduction in baseline average heart rate response as a consequence of M2 receptors stimulation has not been confirmed, imposing a query on current hypothesis for explaining autonomic impairment in Chagas' disease. In this context, possible explanations for the lack of heart rate reduction in the setting of chronic muscarinic stimulation in Chagas' disease have been discussed, based on current knowledge.

Reversal atrial electrical remodeling following cardioversion of long-standing lone atrial fibrillation.

Background: Atrial fibrillation (AF) itself promotes electrophysiological changes, termed 'electrical remodeling', facilitating its recurrence and maintenance. There is evidence that the remodeling process is reversible after restoration of the sinus rhythm (SR). However, the timing for the recovery of electrophysiological properties is still undefined.

Nonlinear mathematical model for predicting long term cardiac remodeling in Chagas' heart disease: introducing the concepts of 'limiting cardiac function' and 'cardiac function deterioration period'.

Cardiac remodeling has been recently investigated in long term follow-up introducing a simple exponential model to describe the time course of cardiac function and dimension changes in Chagas' disease. In the present study, an improved mathematical model to equate time course and cardiac functional changes has been proposed. Present model has been derived from previously validated intuitive assumptions and tested on data set of outpatients with chronic Chagas' disease (51.

Comments on the article by Chen-Scarabelli and Scarabelli: history of medicine in the 'hidden world' and relevant articles in systematic reviews.

When writing a review manuscript, choosing among potentially citable references is an arduous task. Decisions are commonly based on several aspects, ranging from obvious content relevance, passing through impact factor of the journal in which a prospective citable article was written, and reaching to sovereign personal preferences. Articles written in non-English languages or ranked in low impact factor journals are generally overlooked.

Cardiac remodeling and predictors for cardiac death in long-term follow-up of subjects with chronic Chagas' heart disease: a mathematical model for progression of myocardial damage.

In a prospective longitudinal study the occurrence of cardiac death was investigated and ongoing cardiac remodeling retrospectively analyzed in regard to adverse outcome. A cohort of 50 subjects with chronic Chagas' disease stratified according to Los Andes groups 1, 2 and 3 were followed-up for (mean+/-SD) 84.2+/-39.

Comments on the article by Abboud et al. "Peripartum cardiomyopathy: a comprehensive review": a tribute to: A.B. Benchimol and P. Schlesinger.

Peripartum (or postpartum) cardiomyopathy is a rare disease affecting 1:1,500 to 1:15,000 successful pregnancies in otherwise healthy women, has usually a relentless course and roughly 35% six-months mortality rate. In Latin America, Prof. A.

Comments on the article by Rallidis et al: "Effects of smoking on myocardial infarction in young people": illicit drug addiction also contributes to major coronary events among youngsters.

Among environmental factors influencing unfolding of acute coronary events among youngsters, tobacco smoking, a habit acquired at early ages, and illicit drug addiction, stand out. At young ages the myocardium is deprived of active collateral circulation to deal with an acute ischemic insult and major coronary events are predisposed to have serious consequences to cardiac mechanics, impacting lifestyle and quality of life. Planning strategies to reduce the impact of these injurious habits among young people should be considered by the organized and conscious society.

Comment on the article by Vázquez and Márquez-Garcia. High-risk vs. low-risk for thrombo-embolic events: who are in the intermediate-risk group? What should be done then?

Although high risk and low risk profile for thrombo-embolic events have been extensively and intensively investigated in multi-centre trials and described in detail in atrial fibrillation guidelines, the management of those at otherwise intermediate risk is still a 'no-one's zone'. Individual risk profile is mandatory to identify those who will benefit of anti-coagulation therapy and large-scale clinical trials are still awaited to define efficacy and efficiency profile in intermediate-risk group.