[Cardiac arrhythmias and amyloidosis]. / Las arritmias en la amiloidosis cardiaca.

Cardiac amyloidosis (CA) is a form of cardiomyopathy characterized by the extracellular deposit of protein fibers in the myocardium, leading to the development of heart failure, arrhythmias, and electrical conduction system alterations. It is known that most cardiomyopathies have a close relationship with heart rhythm abnormalities, however, CA is specially related to different kinds of arrhythmias even in pre-diagnosis stages. Arrhythmias like atrial fibrillation are present in up to 70% of patients with CA associated with a high risk of cardioembolic complications independent of the risk stratification. Ventricular arrhythmias are frequent, but the use of implantable cardioverter defibrillator has not been demonstrated to improve survival. The Atrial-Ventricular node disease is also common, and is frequently associated with the implantation of a pacemaker, even in asymptomatic patients. In this review, we clarify the recommendations of the most current guidelines, summarize historical and contemporaneous data and describe evidence-based strategies for the management of arrhythmias and their complications in CA.

Diagnostic accuracy of D-dimer to detect left atrial thrombus in patients with atrial fibrillation: A systematic review and meta-analysis.

BACKGROUND: There is conflicting evidence about the use of biomarkers to diagnose left atrial thrombus in patients with atrial fibrillation. OBJECTIVE: The purpose of this study was to assess the diagnostic accuracy of D-dimer to detect left atrial thrombus in patients with atrial fibrillation. METHODS: We searched 4 electronic databases from inception to December 16, 2020. The reference standard was left atrial thrombus detected by transesophageal echocardiography. Study quality was assessed with the Quality Assessment of Diagnostic Accuracy Studies 2 tool. We used a bivariate model to calculate the pooled sensitivity and specificity with their 95% confidence intervals (CIs). The optimal cutoff and predictive values were also estimated. RESULTS: Eleven cross-sectional studies involving 4380 patients were included. The median prevalence of left atrial thrombus was 12%. In 7 studies, the pooled sensitivity of D-dimer at 500 ng/mL was 50% (95% CI 26%-74%) and the pooled specificity was 88% (95% CI 76%-95%). The pooled sensitivity of age-adjusted D-dimer was 36% (95% CI 14%-66%) and the pooled specificity was 99% (95% CI 96%-99%) in 2 studies. The optimal cutoff of D-dimer was 390 ng/mL in 10 studies with a pooled sensitivity of 68% (95% CI 44%-85%) and a pooled specificity of 73% (95% CI 54%-86%). The positive and negative predictive values were 21.8% and 95.4%, respectively. The risk of bias was low or unclear for all domains. Concerns about applicability were low for almost all studies. CONCLUSION: Our meta-analysis suggests that D-dimer has the potential to be useful to rule out left atrial thrombus in patients with atrial fibrillation.

Síndrome de marcapasos: cuál es el mecanismo? / Pacemaker syndrome: what is the mechanism?

Resumen Presentamos un caso de síndrome de marcapasos asociado a la ausencia de sincronía aurículo-ventricular, debido a la colocación invertida e inadvertida de los electrodos, en una paciente portadora de bloqueo aurículo-ventricular completo; para su diagnóstico, es fundamental un cuidadoso análisis del electrocardiograma, las imágenes con rayos X y los electrogramas intracavitarios.

Abstract Pacemaker syndrome: what is the mechanism? We present the case of pacemaker syndrome related to the absence of atrioventricular synchrony, due to inverted and inadvertent placement of the electrodes, in a patient with complete atrioventricular block. A careful analysis of the electrocardiogram, X-ray images and intracavitary electrograms are essential for its diagnosis.

Impact of COVID-19 on pacemaker implant.

Objectives: The purpose of this article was to determine the change in the volume of pacemaker implantations with the COVID-2019 pandemic and to assess the change in the number of pacemaker implants according to etiology during the pandemic. Background: The establishment of a mandatory social isolation have generated a decrease in activities in cardiology units. Methods: Descriptive, cross-sectional study that used a database of a Peruvian Hospital. Time was divided into three categories: Before COVID period and COVID period including Previous to Social isolation (SI) and Social Isolation. The number of pacemaker implantations were compared per the same amount of time. Results: A reduction in the pacemaker implant of 73% (95% CI: 33-113; P < .001) was observed during the COVID-19 pandemic period, and a reduction of 78% of patients with the diagnosis of complete or high-grade atrioventricular block and a reduction in the de-novo pacemaker implant was observed, regardless of the etiology. Conclusions: Our results indicate a very significant reduction (73%) in de-novo pacemaker implantation during the months of the COVID-19 pandemic. The reduction in the number of de-novo pacemaker occurred independent of the etiology.

[Arrhythmias and Sudden Death Risk in Hypertrophic Cardiomyopathy]. / Arritmias y Riesgo de Muerte Súbita en Cardiomiopatía Hipertrófica.

The risk of sudden death in hypertrophic cardiomyopathy is related to the presence of ventricular arrhythmias in most cases. Finding the best schemes to assess the probability of arrhythmic complications will remain a challenge for modern Cardiology. Meanwhile, the multifactorial approach is the best strategy to avoid the unnecessary implantation of devices such as the implantable cardioverter defibrillator. Although the electrocardiogram remains an excellent diagnostic tool, even before echocardiographic expression, it does not have a clear role as a risk factor. However, the identification of associated arrhythmias such as preexcitation or long QT and variants of presentation as apical hypertrophic cardiomyopathy, allows identifying patients with high probability of sudden death. During the last few years, cardiac resonance and quantification of intramyocardial fibrosis (the basic mechanism of ventricular arrhythmias) have gained an important role in the evaluation of these patients.In particular, pediatric patients must have an individualized approach due to the poor prognosis at early ages and the uncertain role of different tools for risk assessment and treatment.