HRH2 and hydrops fetalis: We found similar results when we examined the risk of hospitalization for AMI and HF in patients without history of these conditions within 12 weeks of the initiation of histamine H2 receptor antagonists (estimated odds ratio 1.8, 95% CI, 1.7 to 1.9 and 1.5, 95% CI, 1.4 to 1.6, respectively) or benzodiazepines (estimated odds ratio 1.3, 95% CI 1.3 to 1.4 and 1.6, 95% CI 1.5 to 1.7, respectively) (both analyses shown in Table 2).