Importance of temporal changes in myocardial strain in Takotsubo cardiomyopathy.

Strain imaging is a sensitive marker of myocardial dysfunction and may be underused in Takotsubo cardiomyopathy (TC). We present a case of biventricular TC in which early improvement in left ventricular longitudinal strain predated subsequent improvement in ejection fraction. Early temporal patterns of strain of the left and right ventricles have not previously been described in TC. Our case illustrates how strain can be a sensitive marker for myocardial dysfunction and recovery in TC. Increased use of strain in TC may have further implications on prognosis and management.

Design, synthesis, and biological evaluation of peptidomimetic inhibitors of factor XIa as novel anticoagulants.

Human coagulation factor XIa (FXIa), a serine protease activated by site-specific cleavage of factor XI by thrombin, FXIIa, or autoactivation, is a critical enzyme in the amplification phase of the coagulation cascade. To investigate the potential of FXIa inhibitors as safe anticoagulants, a series of potent, selective peptidomimetic inhibitors of FXIa were designed and synthesized. Some of these inhibitors showed low nanomolar FXIa inhibitory activity with >1000-fold FXa selectivity and >100-fold thrombin selectivity. The X-ray structure of one of these inhibitors, 36, demonstrates its unique binding interactions with FXIa. Compound 32 caused a doubling of the activated partial thromboplastin time in human plasma at 2.4 microM and was efficacious in a rat model of venous thrombosis. These data suggest that factor XIa plays a significant role in venous thrombosis and may be a suitable target for the development of antithrombotic therapy.