TLR4 and myocarditis: Although cardioprotective effects of short-term activation of this receptor have been demonstrated in isolated perfused hearts,41 studies have reported its implication in myocarditis, MI, myocardial I/R injury, heart failure, cardiac arrhythmias, cardiac valve diseases, atherosclerosis, and hypertension.40,42 TLR4 is involved in the etiology of hypertension and introduced as a possible novel therapeutic target for hypertension treatment.