Immune checkpoint inhibitors (ICIs) have revolutionized oncology and transformed the treatment of various malignancies. By unleashing the natural immunological brake of the immune system, ICIs were initially considered an effective, gentle therapy with few side effects. However, accumulated clinical knowledge reveals that ICIs are associated with inflammation and tissue damage in multiple organs, leading to immune-related adverse effects (irAEs). Most irAEs involve the skin and gastrointestinal tract; however, cardiovascular involvement is associated with very high mortality rates, and its underlying pathomechanisms are poorly understood. Ranging from acute myocarditis to chronic cardiomyopathies, ICI-induced cardiotoxicity can present in various forms and entities. Revealing the inciting factors, understanding the pathogenesis, and identifying effective treatment strategies are needed to improve the care of tumor patients and our understanding of the immune and cardiovascular systems.

Background: Autonomic imbalance represents a keystone of chronic heart failure (HF) with substantial clinical and prognostic implications. Baroreceptor activation therapy (BAT) is a new therapeutic strategy to target the autonomic dysbalance by electrical stimulation of carotid baroreceptors. Besides its known beneficial effects on HF parameters, BAT is also supposed to trigger potential antiarrhythmic effects, which may additionally contribute to HF improvement. Case summary: We report on a 70-year-old male with progredient shortness of breath and advanced HF in the context of an extensive cardiovascular history. After optimization of pharmacologic and device-related therapy, the decision was made to implant a BAT system (Barostim Neo, CVRx) to improve functional cardiac parameters and support symptomatic improvement. Implantation was associated with an overall clinical improvement assessed during outpatient visits every 6 months. Frequency of ventricular arrhythmic events declined, and atrial fibrillation ceased spontaneously. Echocardiography revealed an amelioration in left ventricular systolic function. Numbers of HF hospitalization decreased after Barostim implantation. Discussion: We present a patient with an extensive cardiovascular history and fully exploited pharmacologic and device-related therapy, who showed improvement in New York Heart Association (NYHA) functional classification, left ventricular systolic function, and reduction of arrhythmic events following implantation of the BAT device. This case presents an additional positive potential of BAT for HF patients in terms of reduction of arrhythmia burden. These results should be confirmed by further clinical trials.

Background: Cardiac implantable electronic devices (CIEDs) are prone to electromagnetic interference. Common sources include household electronics and industrial machinery. However, medical equipment can also trigger interferences and cause CIED malfunction. Case summary: We report on a 79-year-old male with sudden onset of presyncope. He has a long history of device therapy, including an active VVI leadless pacemaker and an abandoned abdominal pacemaker with epicardial leads. Automatic reactivation of the abandoned pacemaker due to reaching end-of-life mode led to interaction with the active pacemaker, inhibiting it in its function. Due to elevated capture threshold and insufficient output, pacing by the reactivated pacemaker was accompanied by intermittent loss of myocardial capture and patient symptoms. By changing the mode to VOO and increasing the pacing rate of the active pacemaker, the interaction was prevented as an intermittent solution. The final therapy consisted of explanting the pulse generator of the abdominal pacemaker. Discussion: We present a patient with a deactivated abandoned cardiac pacemaker, which self-activated after reaching end-of-life mode and triggered an interaction with his active pacemaker. This case emphasizes the importance of explanting old devices to avoid potential interaction.

Immune checkpoint inhibitors (ICIs) have transformed cancer therapy but are associated with a growing spectrum of cardiovascular immune‐related adverse events. Among these, arrhythmias represent a rare yet potentially life‐threatening complication. ICI‐induced arrhythmias encompass a wide clinical spectrum, including atrial arrhythmias, conduction disturbances and malignant ventricular arrhythmias. This review summarizes the current evidence on the incidence, clinical presentation, pathophysiological mechanisms and management of ICI‐associated arrhythmias. We discuss the limitations of available data, which are largely derived from case reports, small series and retrospective registries, and highlight the implications for clinical practice. Improved understanding of ICI‐induced arrhythmias is essential to balance oncological efficacy with cardiovascular safety in this, rapidly expanding, patient population.