[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.

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.

[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.