Herzschrittmachertherapie und Elektrophysiologie最新文献

Patients with chronic kidney disease face a high risk of sudden cardiac death, particularly in more advanced stages of renal dysfunction. Ventricular arrhythmias are prevalent and contribute to the heightened cardiovascular mortality. This review aims to explore the intricate interplay of disease-specific risk factors, arrhythmic triggers, and electrolyte disorders that amplify susceptibility to ventricular arrhythmias and sudden cardiac death in this population and influence the efficacy of available treatments.

Cardiac amyloidosis is an infiltrative cardiomyopathy characterized by the extracellular deposition of amyloid fibrils within the myocardium. Beyond heart failure, patients with cardiac amyloidosis commonly present with arrhythmias and conduction system disorders. Atrial fibrillation is observed in up to 80% of patients at the time of diagnosis, with patients typically maintaining normal heart rates due to concurrent atrioventricular nodal disease. The thromboembolic risk is particularly high in patients with cardiac amyloidosis, and left atrial thrombi have been observed even in the absence of atrial fibrillation. Conduction system diseases are also highly prevalent, often necessitating permanent pacemaker implantation. The use of implantable defibrillators in this population remains controversial. This overview of published data and therapeutic strategies related to arrhythmias and conduction system disorders aims to assist readers in decision-making in complex clinical scenarios.

Cardiac sarcoidosis (CS) is difficult to diagnose and often requires a careful evaluation of numerous diagnostic findings. Typical features at initial presentation are a high-grade atrioventricular (AV) block and ventricular tachycardias that cannot be explained by other common entities, especially in younger patients. CS is frequently misdiagnosed and inappropriately treated, which may have deleterious consequences for the patients. In this review article, we focus on special features of the arrhythmias typical of sarcoidosis and also discuss the underlying substrate and the approach in special situations. Furthermore, we provide recommendations from our daily clinical experience, discuss open questions, and explain the need for research.

As an alternative to transvenous ICD systems, two non-transvenous ICD systems have been established in recent years: The subcutaneous ICD (S-ICD), which has been established for several years, has a presternal electrode that is implanted subcutaneously and offers a shock function and, to a limited extent, post-shock pacing. In addition, the extravascular ICD (EV-ICD) has been available in Europe since 2023 which does not require transvenous electrodes and offers the option of providing patients with antibradycardic and antitachycardic stimulation in combination with a conventional ICD function. The lead of this device is implanted substernally. Initial implantation results are promising in terms of safety and effectiveness. Both systems avoid possible complications of transvenous electrodes. This article provides practical guidance for the implantation technique and possible complications.

Background: Sleep apnea is a widespread and yet still underdiagnosed condition. Various studies from the past have provided evidence that there is a link between sleep apnea and various cardiovascular diseases, including arrhythmias.

Objective: The aim of this article is to provide an overview of the current study situation and to point out possible consequences relevant to everyday life.

Material and methods: A systematic search was carried out in various databases using the keywords sleep apnea (OSAS/SA) and arrhythmias/dysrhythmias.

Results: There are several pathophysiological links between sleep-related breathing disorders and cardiac arrhythmias, the most important of which appear to be intrathoracic pressure, increased adrenergic tone as well as recurrent hypoxia and hypercapnia. This results in an increased occurrence of clinically relevant arrhythmias, such as atrial fibrillation, symptomatic bradycardia, high-grade atrioventricular (AV) blocks as well as ventricular arrhythmias in patients with untreated sleep apnea. These pathologies also appear to be positively influenced by the treatment of sleep apnea.

Conclusion: A close correlation between sleep apnea and cardiac arrhythmias is undisputed. Large randomized studies in this respect are so far rare but it is undisputed that a thorough search should be carried out for sleep apnea and consistently treated in patients with a history of cardiac disease as this can have a relevant influence on the treatment and ultimately the prognosis of the patient.

Thyroid dysfunction is associated with characteristic changes in heart rate and arrhythmias. Thyroid hormones act through genomic and non-genomic effects on myocytes and influence contractility, relaxation and action potential duration through a variety of mechanisms. Atrial fibrillation is the most common arrhythmia associated with thyroid dysfunction, it occurs in both euthyroidism and hyperthyroidism in clear association with T4 levels. Mechanistically, in the hyperthyroid state, increased automaticity and triggered activity, together with a shortened refractory period and slowing of the conduction speed, lead to the initiation and maintenance of multiple intraatrial reentry circuits. Influences from the autonomic nervous system and hemodynamics controlled by thyroid hormones act as modulators for arrhythmias, which are promoted by a corresponding substrate (significant impact of comorbidities). Concerning therapy, in addition to treating hyperthyroidism, the initial therapeutic focus is on adequate rate control and anticoagulation in patients with a high risk of thromboembolism. Ablation of atrial fibrillation can be considered later on, although there is an increased likelihood of recurrence compared to patients without hyperthyroidism.Prolongation of the QT interval and increase in QT dispersion are involved in the formation of ventricular arrhythmias. Epidemiological data suggest an association of elevated T4 levels with ventricular arrhythmias and sudden cardiac death. However, this seems to be mainly relevant for patients with underlying cardiac disease (e.g. ICD users).

Chemotherapy is the cornerstone of antineoplastic treatment in patients with malignancies. The cardiotoxic effect of antineoplastic therapy has been known for many decades. Part of chemotherapy-induced cardiotoxicity is the development of heart rhythm disturbances. This short review aims to provide a compact overview for the clinical cardiologist of the dysrhythmic potential created by antineoplastic agents in cancer survivors.