Autoimmune diseases substantially increase the risk of atrial and ventricular arrhythmias and sudden cardiac death through shared immune-mediated mechanisms. Pro-inflammatory cytokines, autoantibodies, and progressive myocardial fibrosis disrupt ion channel function, impair conduction, and create re-entrant substrates. Across systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and systemic sclerosis (SSc), these pathways manifest as atrial fibrillation, ventricular arrhythmias, conduction disease, and heightened arrhythmic mortality. Anti Ro/SSA antibodies, in particular, contribute to QT prolongation and atrioventricular (AV) block, while cytokines such as TNF α, IL 1β, and IL 6 remodel electrophysiological properties and promote fibrosis. Advanced cardiac imaging, especially cardiac magnetic resonance (CMR), detects inflammation and fibrosis even when ejection fraction is preserved, enabling earlier intervention. Management requires a dual approach: standard arrhythmia therapies alongside aggressive control of systemic inflammation with disease-specific immunosuppression. Despite growing evidence, major gaps remain, including the absence of randomized trials targeting immune-driven arrhythmias and the need for integrated risk models incorporating inflammatory biomarkers.

The subcutaneous implantable cardioverter-defibrillator and extravascular implantable cardioverter-defibrillator do not require intravascular, intracardiac, or epicardial leads, making them attractive alternatives to transvenous implantable cardioverter-defibrillators in patients without bradycardia pacing or cardiac resynchronization therapy indications. These systems are especially useful for patients with venous access challenges and those at risk for endovascular infections, including patients with renal failure or those who are immunocompromised. Women with prior or anticipated breast surgery, such as mastectomy or breast reconstruction surgery, or those who are lactating present unique anatomic, procedural, and post-operative quality-of-life considerations. This commentary provides a practical, scenario-based framework for managing this unique patient group. Key considerations include individualized incision and pulse generator planning, proactive multidisciplinary coordination, procedure-specific management, and shared decision-making in patients with prior or anticipated breast augmentation or reduction, pregnancy, lactation, mastectomy, radiation therapy, and breast imaging.