The systemic inflammatory response following global myocardial ischemia/reperfusion (I/R) injury is a critical driver of poor outcomes. Both pyroptosis and necroptosis are involved in the systemic inflammatory response and contribute to regional myocardial I/R injury. This study aimed to explore the effect of necrosulfonamide (NSA) on post-resuscitation myocardial dysfunction in a rat model of cardiac arrest. Sprague-Dawley rats were randomly categorized to Sham, CPR and CPR-NSA groups. For rats in the latter two groups, ventricular fibrillation was induced without treatment for 6 min, with cardiopulmonary resuscitation (CPR) being sustained for 8 min. Rats were injected with NSA (10 mg/kg in DMSO) or vehicle at 5 min following return of spontaneous circulation. Myocardial function was measured by echocardiography, survival and neurological deficit score (NDS) were recorded at 24, 48, and 72 h after ROSC. Western blotting was used to assess pyroptosis- and necroptosis-related protein expression. ELISAs were used to measure levels of inflammatory cytokine. Rats in the CPR-NSA group were found to exhibit superior post-resuscitation myocardial function, and better NDS values in the group of CPR-NSA. Rats in the group of CPR-NSA exhibited median survival duration of 68 ± 8 h as compared to 34 ± 21 h in the CPR group. After treatment with NSA, NOD-like receptor 3 (NLRP3), GSDMD-N, phosphorylated-MLKL, and phosphorylated-RIP3 levels in cardiac tissue were reduced with corresponding reductions in inflammatory cytokine levels. Administration of NSA significantly improved myocardial dysfunction succeeding global myocardial I/R injury and enhanced survival outcomes through protective mechanisms potentially related to inhibition of pyroptosis and necroptosis pathways.