13) Moreover, a recent study revealed that absence of LV function recovery within 1 week (EF < 50%) was an independent factor associated with mortality.14) An awareness of LVOT obstruction is an important factor in understanding hemodynamics in stress-induced cardiomyopathy. Basal hypercontractility is one of the characteristics, and can be aggravated
with the use of inotropic agents such Inhibitors,research,lifescience,medical as dobutamine and dopamine. The Venturi effect around the LVOT results in the movement of the anterior mitral leaflets toward the interventricular septum in the systolic phase ["systolic anterior motion" (SAM)]. The reduction in forward flow contributes to the resultant low cardiac output. This effect may occur in up to one-quarter of patients presenting with a septal bulge associated with SAM and mitral regurgitation (MR).15) Other reports have confirmed structural abnormalities associated with LVOT obstruction, Inhibitors,research,lifescience,medical such as mid-ventricular septal thickening (particularly in elderly women).16) LVOT obstruction is a dynamic phenomenon depending on the hemodynamics at that time point,
and thus echocardiography Inhibitors,research,lifescience,medical is a useful and readily accessible tool if unexplained hypotension or shock is observed. Apical five-chamber and parasternal long-axis views in two-dimensional (2D) images with color Doppler guidance can help in the evaluation of SAM severity. In the parasternal long-axis view, the M mode at the level of the mitral
valve may give information about the relationship between the interventricular septum and anterior Inhibitors,research,lifescience,medical mitral leaflet. MR can be observed with or without SAM.17),18) SAM can occur concomitantly with MR due to hemodynamic alteration, whereas the mechanism of MR without SAM may be different. The main factor involved in MR without Inhibitors,research,lifescience,medical SAM seems to relate to displacement of the papillary muscle, which leads to impaired leaflet coaptation secondary to tethering (Fig. 2). One study showed that patients with significant (moderate-to-severe or severe) acute MR had more depressed LVEF and a less complete and slower recovery of LV function.17) These findings imply Thiamine-diphosphate kinase that acute MR should be SAHA HDAC molecular weight considered to be a potential marker of an adverse clinical course requiring aggressive treatment. Fig. 2 Moderate mitral regurgitation detected by parasternal long axis view (A) and apical four chamber view (B). Atypical forms of stress-induced cardiomyopathy have increasingly been reported. Transient mid-ventricular ballooning with preserved basal and apical contractility (inverted takotsubo cardiomyopathy) (Fig. 3) has been described.9),19) The morphology of RWMA can be quite different, varying from a small area of akinesis limited to the LV apex to a large area of LV akinesis.20) Rare (but serious) complications such as LV free wall rupture and consequent death can occur in a manner similar to that seen in patients with MI.21) Fig.