Cannabis and Sudden Cardiac Death: A Case Series with Narrative Literature Review

Background/Objectives: Cannabis is the most widely used illicit substance worldwide, particularly among young adults, with growing acceptance following medical and recreational legalization. Although generally perceived as a drug with low acute toxicity, an expanding body of evidence indicates that cannabinoids can exert relevant cardiovascular effects, including arrhythmias, myocardial ischemia, and sudden cardiac death (SCD). These mechanisms are mediated through complex, dose-dependent interactions among CB1 and CB2 receptors, autonomic imbalance, and endothelial dysfunction. Nevertheless, cannabis-related fatalities remain underestimated in both clinical and forensic settings. Case presentation: Three cases of sudden unexpected death in previously healthy men aged 28, 37, and 37 years are described. All were found deceased at home under non-suspicious circumstances. Forensic autopsies ruled out trauma, coronary atherosclerosis, congenital malformations, or cardiomyopathy. Histological analyses consistently revealed polymorphic myocardial alterations, including interstitial edema, fiber disruption, and focal myocytolysis, without inflammatory infiltrates or necrosis. Toxicological examinations demonstrated the presence of Δ9-tetrahydrocannabinol (THC) and metabolites in peripheral blood and urine, while alcohol and other illicit drugs tested negative. In each case, the cause of death was attributed to arrhythmic sudden cardiac death in temporal association with cannabis use. Conclusions: This case series, integrated with a narrative review of current literature, supports the hypothesis that cannabis consumption can contribute to fatal arrhythmias even in young adults without conventional cardiovascular risk factors. The convergence of autopsy, histopathological, and toxicological findings suggests a potential causal link between THC exposure and sudden unexpected death. These results highlight the importance of systematic postmortem investigations in suspected drug-related fatalities and underscore the need for greater awareness among clinicians, forensic pathologists, and policymakers regarding the underestimated cardiovascular toxicity of cannabis.