Despite epidemiological evidence of cardiovascular complications in asthmatics, the direct contribution of asthmatic pathophysiology to cardiovascular effects is unknown. Considering parallels in underlying pathophysiology, we tested the hypothesis that presence of systemic allergy and asthma worsens the outcome of myocardial ischemia-reperfusion injury. Systemic allergy and asthma were created in rabbits by repeated intraperitoneal injections of allergen with adjuvant, followed by an airway challenge in two groups. Non-sensitized animals served as controls (C). In situ myocardial ischemia-reperfusion was induced in anesthetized animals by 30 minutes ligation of a coronary artery, followed by 3 hours of reperfusion. Ischemia-reperfusion was done at 24 hours (1dB) and 7 days (7dB) after the last intraperitoneal injection and at 24 hours (1dAWCH) and 7 days (7dAWCH) after airway challenge. The infarct size (determined by 2,3,5-Triphenyltetrazolium chloride staining, normalized to area at risk) was significantly higher in all sensitized groups compared to control (1dB, 31 ± 4; 7dB, 28.9 ± 2.6; 1dAWCH, 66.1 ± 4.1; 7dAWCH 28.9 ± 9.2; C, 16.7 ± 3.2; means ± SEM; p < 0.01 by ANOVA; n = 6). The 1dAWCH group showed significantly greater infarct than all other groups (p < 0.05). Myocardial neutrophil infiltration was significantly higher in the sensitized groups compared to control (p < 0.01). Tissue neutrophil counts showed a strong positive correlation to infarct sizes (r² = 0.9). These observations indicate that the presence of systemic allergy and asthma is associated with increased myocardial neutrophil infiltration during acute ischemia-reperfusion and increased size of the resulting infarct.