While systemic administration of TLR9 agonist has been shown to attenuate myocardial hypertrophy and dysfunction in both isoproterenol and pressure overload-induced cardiomyopathy [3,17], we found worsening of diastolic function in a model of diastolic HF with no attenuating effects on systolic function. This evidence concerns the gene TLR9 and hydrops fetalis.