Papel dos Níveis de Sódio na Fibrilação Atrial na Insuficiência Cardíaca: Jogador Ativo ou Bystander?

BackgroundThe coexistence of hyponatremia and atrial fibrillation (AF) increases morbidity and mortality in patients with heart failure (HF). However, it is not established whether hyponatremia is related to AF or not.ObjectiveOur study aims to seek a potential association of hyponatremia with AF in patients with reduced ejection fraction heart failure (HFrEF).MethodsThis observational cross-sectional single-center study included 280 consecutive outpatients diagnosed with HFrEF with 40% or less. Based on sodium concentrations ≤135 mEq/L or higher, the patients were classified into hyponatremia (n=66) and normonatremia (n=214). A p-value <0.05 was considered significant.ResultsMean age was 67.6±10.5 years, 202 of them (72.2%) were male, mean blood sodium level was 138±3.6 mEq/L, and mean ejection fraction was 30±4%. Of those, 195 (69.6%) patients were diagnosed with coronary artery disease. AF was detected in 124 (44.3%) patients. AF rate was higher in patients with hyponatremia compared to those with normonatremia (n=39 [59.1%] vs. n=85 [39.7%), p= 0.020). In the logistic regression analysis, hyponatremia was not related to AF (OR=1.022, 95% CI=0.785–1.330, p=0.871). Advanced age (OR=1.046, 95% CI=1.016–1.177, p=0.003), presence of CAD (OR=2.058, 95% CI=1.122–3.777, p=0.020), resting heart rate (OR=1.041, 95% CI=1.023–1.060, p<0.001), and left atrium diameter (OR=1.049, 95% CI=1.011–1.616, p=0.002) were found to be predictors of AF.ConclusionAF was higher in outpatients with HFrEF and hyponatremia. However, there is no association between sodium levels and AF in patients with HFrEF.     

Síndrome Cardiorrenal Aguda: Qual Critério Diagnóstico Utilizar e sua Importância para o Prognóstico?

The absence of a consensus about the diagnostic criteria for acute cardiorenal syndrome (ACRS) affects its prognosis. This study aimed at assessing the diagnostic criteria for ACRS and their impact on prognosis. A systematic review was conducted using PRISMA methodology and PICO criteria in the MEDLINE, EMBASE and LILACS databases. The search included original publications, such as clinical trials, cohort studies, case-control studies, and meta-analyses, issued from January 1998 to June 2018. Neither literature nor heart failure guidelines provided a clear definition of the diagnostic criteria for ACRS. The serum creatinine increase by at least 0.3 mg/dL from baseline creatinine is the most used diagnostic criterion. However, the definition of baseline creatinine, as well as which serum creatinine should be used as reference for critical patients, is still controversial. This systematic review suggests that ACRS criteria should be revised to include the diagnosis of ACRS on hospital admission. Reference serum creatinine should reflect baseline renal function before the beginning of acute kidney injury.     

Sincronia Ventricular na Estimulação Cardíaca Parahissiana: Alternativa por Ativação Cardíaca Fisiológica (Estimulação Indireta do Feixe de His)?

Background Artificial cardiac pacing by direct or indirect His bundle capture results in synchronous ventricular contraction (physiological pacing).Objectives To compare cardiac synchronization, technical characteristics, and electronic parameters between two techniques of indirect His-bundle pacing: non-selective (NS-HBP) vs para-Hisian pacing (PHP).Methods The experimental intervention (between November 2019 and April 2020) consisted of implanting a DDD pacemaker in patients who had left ventricular ejection fraction (LVEF) > 35%. The resulting cardiac synchronization was compared using an electrocardiographic algorithm that analyzed QRS variation and the technical characteristics of non-selective Hisian pacing (DDD-His) and para-Hisian pacing (DDD-Var).Results Of 51 total patients (men: 28), 66.7% (34) were allocated to the DDD-Var group and 33.3% (17) to the DDD-His group. The mean ages in each group were 74 and 79 years, respectively. In the DDD-Var group, QRS variation (ventricular synchrony) improved after implantation (p < 0.001). In post-implantation ECG, 91.2% of the DDD-Var group presented a physiological pacing pattern, which was similar to the DDD-His group (88.2%; p = 0.999). The paced QRS axis was also similar (physiological) for both groups. Intraoperative fluoroscopy time (XRay) during implantation was lower for the para-Hisian technique (median 7 min in the DDD-Var group vs 21 min in the DDD-His group, p < 0.001). The mean QRS duration increased in the DDD-Var group (114.7 ms pre-implantation vs 128.2 ms post-implantation, p = 0.044). The mean post-implantation R-wave amplitude was 11.2 mV in the DDD-Var group vs 6.0 mV in the DDD-His group, p = 0.001.Conclusion Para-Hisian pacing appears to indirectly recruit the His bundle, which would make this an effective and comparable strategy for physiological pacing, resulting in synchronous ventricular contraction similar to that of non-selective Hisian pacing.