Variabilidad del ritmo cardíaco en pediatría: aspectos metodológicos y aplicaciones clínicas

Heart rate variability (HRV) corresponds to variations in heart rate or beat-beat time interval. This parameter reflects the status of the autonomic mechanisms of cardiovascular control, which may be influenced by changes characteristic of the life cycle of people, sedentary lifestyle, and various disease processes that directly or indirectly generate changes in the HRV and shift the autonomic balance, either towards greater sympathetic or parasympathetic influence on the heart. These antecedents support the use of HRV indices for the diagnosis and monitoring of various nosological entities in adults. However, there has been limited progress in the study of temporal variations in heart rhythm in the pediatric population. This article aims to describe the physiological and technical aspects of HRV in the pediatric population to provide a background that allows optimizing the application of these parameters in this age group.     

Flutter Atrial na Síndrome do PRKAG2: Características Clínicas e Eletrofisiológicas

BackgroundPRKAG2 syndrome is a rare autosomal dominant disease, a phenocopy of hypertrophic cardiomyopathy characterized by intracellular glycogen accumulation. Clinical manifestations include ventricular preexcitation, cardiac conduction disorder, ventricular hypertrophy, and atrial arrhythmias.ObjectiveTo compare the clinical and electrophysiological characteristics observed in patients with atrial flutter, with and without PRKAG2 syndrome.MethodsAn observational study comparing patients with atrial flutter: group A consisted of five patients with PRKAG2 syndrome from a family, and group B consisted of 25 patients without phenotype of PRKAG2 syndrome. The level of significance was 5%.ResultsAll patients in group A had ventricular preexcitation and right branch block, and four had pacemakers (80%). Patients in group A were younger (39±5.4 vs 58.6±17.6 years, p=0.021), had greater interventricular septum (median=18 vs 10 mm; p<0.001) and posterior wall thickness (median=14 vs 10 mm; p=0.001). In group A, four patients were submitted to an electrophysiological study, showing a fasciculoventricular pathway, and atrial flutter ablation was performed in tree. All patients in group B were submitted to ablation of atrial flutter, with no evidence of accessory pathway. Group B had a higher prevalence of hypertension, diabetes mellitus, coronary artery disease and sleep apnea, with no statistically significant difference.ConclusionPatients with PRKAG2 syndrome presented atrial flutter at an earlier age and had fewer comorbidities when compared to patients with atrial flutter without mutation phenotype. The occurrence of atrial flutter in young individuals, especially in the presence of ventricular preexcitation and familial ventricular hypertrophy, should raise the suspicion of PRKAG2 syndrome.     

Exposición crónica a la altura. Características clínicas y diagnóstico

Chronic exposure to altitude has been associated with hypobaric hypoxia in its inhabitants. Two entities have been associated with it, high altitude pulmonary hypertension and chronic mountain sickness. Its physiological and pulmonary circulation characteristics are described, as well as its clinical profile and diagnosis.Key words: Pulmonary circulation, Pulmonary hypertension, Altitude, Chronic mountain sickness, Chronic hypoxia     

Interação Letal entre Síndrome Hemofagocítica e Insuficiência Cardíaca Recentemente Desenvolvida

Background:Hemophagocytic syndrome (HPS) ia s devastating hyperinflammatory syndrome. Heart failure (HF) with preserved ejection fraction (HFpEF) status is closely correlated with increased inflammation, both systemic and intramyocardial.Objectives:This study sought to determine mortality predictors and reliable follow-up parameters in HPS that developed HFpEF during the clinical course.Method:Thirty-nine patients, diagnosed as HPS, according to HLH 2004 diagnostic criteria, with an HScore of ≥169 and proven bone marrow aspiration or biopsy, were recruited retrospectively. Both traditional, serum C-reactive protein, albumin and ferritin levels with lymphocyte, and platelet counts, as well as non-traditional risk factors, neutrophil-to-lymphocyte count (NLR), monocyte-to-lymphocyte count (MLR), mean platelet volume (MPV), and N-Terminal pro-brain natriuretic peptide (NTproBNP), were investigated retrospectively. The relationship between time-changed laboratory values both among themselves and with mortality. The overall significance level was set at 5%.Results:This study showed that temporal change of cardiothoracic ratio (CTR), serum NTproBNP, ferritin, CRP, and albumin levels were detected as mortality predictors (p<0.05, for all) in the univariate analysis. Lymphocyte and platelet counts with NLR and MPV values were also significant (p<0.05). The relationship between NT-proBNP and increased systemic inflammatory markers proved to be significant. In addition to traditional risk factors, serum ferritin levels, NLR, MLR, and MPV levels also proved to be significantly correlated with each other.Conclusion:Accompanied by reliable follow-up parameters, rapid diagnosis and aggressive anti-inflammatory treatment with tight volume control can be life-saving in HPS patients who suffer from HFpEF. Close monitoring of inflammation may predict the outcome of patients suffering from HFpEF.     

Síndrome cardiorrenal: clasificación,fisiopatología,diagnóstico y tratamiento. Una revisión de las publicaciones médicas

The cardiorenal syndrome is a complex entity in which a primary heart dysfunction causes kidney injury (Types 1 and 2) and vice versa (Types 3 and 4), being either acute or chronic events, or maybe the result of a systemic disease that involves both organs (Type 5). Approximately 49% of heart failure cases present some grade of kidney dysfunction, significantly increasing morbidity and mortality rates. Its pathogenesis involves a variety of hemodynamic, hormonal and immunological factors that in the majority of cases produce fluid overload; the diagnosis and treatment of such constitutes the disease’s management basis. Currently, a clinical based diagnosis is insufficient and the use of biochemical markers, such as natriuretic peptides, or lung and heart ultrasound is required. These tools, along with urinary sodium levels, allow the evaluation of therapy effectiveness. The preferred initial decongestive strategy is based on a continuous infusion of a loop diuretic with a step-up dosing regimen, aiming for a minimal daily urine volume of 3 liters, with the possibility to sequentially add potassium sparing diuretics, thiazide diuretics and carbonic anhydrase inhibitors to reach the diuresis goal, leaving ultrafiltration as a last resource due to its higher rate of complications. Finally, evidence-based therapy should be given to improve quality of life, decrease mortality, and delay the deterioration of kidney and heart function over the long term.     

Evolução Tardia das Próteses Biológicas e Mecânicas em Posição Aórtica

BackgroundDespite constant improvement and refinement of the prostheses, the decision between mechanical and biological valves for aortic valve replacement is still controversial.ObjectiveTo compare outcomes of aortic valve replacement with bioprosthesis and mechanical prosthesis.MethodsThis was an observational, historical cohort study with review of medical records. A total of 202 patients who underwent heart valve replacement surgery between 2004 and 2008 were selected, with a mean follow-up of 10 years. The level of significance set at 5%.ResultsMean age of patients was approximately 50 years; most patients were male (70%). Overall mortality- and reoperation-free survival was significantly higher in patients with mechanical prosthesis (HR=0.33; 95%CI=0.13-0.79; p=0.013). No difference was found in late mortality between the two groups. On the other hand, the risk of reoperation was significantly higher in patients with bioprosthesis than mechanical prosthesis (HR=0.062; 95%CI=0.008-0.457; p=0.006). The risk of composite adverse events – stroke, bleeding, endocarditis, thrombosis and paravalvular leak – was similar between the groups (HR=1.20; 95%CI= 0.74-1.93; p=0.44). The risk of bleeding was significantly higher in patients with mechanical prosthesis (HR=3.65; 95%CI= 1.43-9.29; p = 0.0064), although no case of fatal bleeding was reported.ConclusionNo difference in 10-year mortality was found between the groups. The risk of reoperation significantly increases with the use of bioprosthesis, especially for patients younger than 30 years. Patients with mechanical prosthesis are at increased risk of nonfatal bleeding.     

Tópicos Emergentes em Insuficiência Cardíaca: Novos Paradigmas na Amiloidose Cardíaca

Recent evidence suggests cardiac amyloidosis (CA) is a mostly underdiagnosed condition, particularly in the transthyretin-mediated form, and is a frequent cause of heart failure with preserved ejection fraction (HFpEF) in the elderly. New paradigms about CA also involve the development of disease-modifying specific therapies. This article summarizes these new concepts.     

Producción científica en insuficiencia cardiaca en Perú: un estudio bibliométrico

Objective:

To analyze the Peruvian scientific production on Heart Failure (HF) in the period 2000-2020.

Methods:

We performed an observational bibliometric study, in the Scopus and Scielo database, of documents published on heart failure by an author with Peruvian affiliation, between the years 2000 and 2020. We describe variables of scientific production, number of annual publications, documents, characteristics of the publications, and institutions. The collaborative networks were analyzed by building a network of nodes using the VOSViewer v1.6.5 software.

Results:

A 236 publications were found in Scopus and 55 in Scielo. The largest number of documents were original articles followed by review articles. The journal “The Lancet” and “Revista Peruana de Medicina Experimental y Salud Pública” were those that had the highest number of publications. Thirty-one countries were registered that had at least 5 documents published with an author from Peru. Scientific collaboration was mainly with the United States and at the regional level with Argentina. 55 documents were published with only Peruvian authors.

Conclusion:

The scientific production in HF by Peruvian authors is in exponential growth. And the Universidad Peruana Cayetano Heredia/CRÓNICAS is the Peruvian institution with the most publications on it.     

Características y evolución de los pacientes con amiloidosis sistémica y compromiso cardíaco

Objective:

To estimate the prevalence of cardiac amyloidosis in patients with systemic amyloidosis. Compare survival rates based on whether they show cardiac involvement.

Methods:

A retrospective cohort study of patients with systemic amyloidosis from the Institutional Amyloidosis Registry of the Hospital Italian of Buenos Aires from 2010 to 2019. Heart involvement is considered to be the presence of symptoms and/or images consistent with amyloidosis, and there is no other reason to explain it. All deaths due to causes were evaluated. The survival rate was estimated by Kaplan-Meier. Cox regression model was used to evaluate factors related to mortality. Heart transplantation was evaluated in a competitive risk regression model.

Results:

The prevalence of heart involvement is 63%. For the group with heart damage, the death rate was 14/1,000 person-months, and for patients without damage, the death rate was 5/1,000 person-months. The 5-year overall survival rate for patients with heart involvement was 44%, while that for patients without damage was 67% (p = 0.02). The original HR for heart involvement was 2.09 (p = 0.02). Age showed that HRa was 1.06 (p <0.01). The sub-HR estimated by the competitive risk regression model are 1.86 (95% CI 0.99-3.49) p = 0.05.

Conclusion:

Cardiac involvement is an important prognostic factor in patients with amyloidosis.Key words: Amyloidosis, Immunoglobulin light chain amyloidosis, Familial amyloidosis, Restrictive cardiomyopathy     

Características e Tendências na Mortalidade em Diferentes Fenótipos de Insuficiência Cardíaca na Atenção Primária

Background:The classification of heart failure (HF) by phenotypes has a great relevance in clinical practice.Objective:The study aimed to analyze the prevalence, clinical characteristics, and outcomes between HF phenotypes in the primary care setting.Methods:This is an analysis of a cohort study including 560 individuals, aged ≥ 45 years, who were randomly selected in a primary care program. All participants underwent clinical evaluations, b-type natriuretic peptide (BNP) measurements, electrocardiogram, and echocardiography in a single day. HF with left ventricular ejection fraction (LVEF) < 40% was classified as HF with reduced ejection fraction (HFrEF), LVEF 40% to 49% as HF with mid-range ejection fraction (HFmrEF) and LVEF ≥ 50% as HF with preserved ejection fraction (HFpEF). After 5 years, the patients were reassessed as to the occurrence of the composite outcome of death from any cause or hospitalization for cardiovascular disease.Results:Of the 560 patients included, 51 patients had HF (9.1%), 11 of whom had HFrEF (21.6%), 10 had HFmrEF (19.6%) and 30 had HFpEF (58.8%). HFmrEF was similar to HFpEF in BNP levels (p < 0.001), left ventricular mass index (p = 0.037), and left atrial volume index (p < 0.001). The HFmrEF phenotype was similar to HFrEF regarding coronary artery disease (p = 0.009). After 5 years, patients with HFmrEF had a better prognosis when compared to patients with HFpEF and HFrEF (p < 0.001).Conclusion:The prevalence of ICFEI was similar to that observed in previous studies. ICFEI presented characteristics similar to ICFEP in this study. Our data show that ICFEi had a better prognosis compared to the other two phenotypes.