When Chronic Risk Meets Acute Strain: Sudden Cardiac Death and Cardiovascular Vulnerability in Firefighters.

Cardiovascular disease remains the leading cause of line-of-duty mortality among firefighters. Sudden cardiac death occurs disproportionately during emergency operations, particularly fire suppression, suggesting an interaction between occupational stressors and underlying cardiovascular vulnerability. This narrative review integrates epidemiologic, mechanistic, and clinical data from observational studies, systematic reviews, and contemporary cardiovascular guidelines. A structured literature search of PubMed and Google Scholar identified studies addressing cardiovascular disease, sudden cardiac death, occupational stress, and autonomic regulation in firefighters. Autopsy and case-control data indicate that most duty-related sudden cardiac deaths occur in the presence of underlying coronary atherosclerosis. Firefighters exhibit a high prevalence of cardiovascular risk factors, including hypertension (10%-44%), obesity (14%-60%), dyslipidemia (20%-56%), and metabolic syndrome (∼22%); these rates exceed those reported in age-matched general-population samples. Emergency operations are associated with marked sympathetic activation, hemodynamic stress, and circadian perturbation, which may promote plaque destabilization, myocardial ischemia, and ventricular arrhythmia. Additionally, occupational stress and sleep disturbance are linked to autonomic imbalance, potentially increasing arrhythmic susceptibility. Sudden cardiac death in firefighters reflects the interaction between baseline cardiometabolic risk and intermittent high-intensity physiologic stress rather than a distinct occupational disease entity. Early risk identification, guideline-directed therapy, and recognition of occupational stressors are central to cardiovascular risk reduction in this population.