Alterations in left ventricular diastolic twist mechanics during acute human cardiac allograft rejection.

Abstract

Acute cardiac allograft rejection is associated with altered diastolic twist mechanics in the absence of any demonstratable systolic abnormalities. During rejection, myocardial edema and other factors may result in intrinsic changes of the elastic properties of the myocardium, thereby leading to modification of recoil forces responsible for the early, rapid unwinding of the deformed ventricle.

Assessment of Left Ventricular Torsional Deformation by Doppler Tissue Imaging

“…The importance of LV torsional behavior as a sensitive indicator of LV performance has been previously corroborated by radiographic tracking of myocardial markers, [5][6][7][8][9] optical devices, 10 and 2D echocardiography. 11,12 In the past decade, tissue tagging magnetic resonance imaging (MRI) has enabled noninvasive measurement of LV myocardial deformation in 3D space [13][14][15] and prompted investigation of LV torsion in various cardiac diseases.…”

Alterations in left ventricular twist mechanics with inotropic stimulation and volume loading in human subjects.

“…End-diastolic volume pressure (EDP) were defined at the peak R wave ESV and end-systolic pressure (ESP) were define( of minimum LV volume. Stroke volume (SV=1 and ejection fraction (EF=SV/EDV) were alsc Effective arterial elastance was derived from LV1 of LVPCS) to estimate LV afterload (Ea=LVPm./, LV twist was computed using a modification of first described by Beyar et al15 20 To eliminate m ated with simple cardiac translation and fixed bc three-dimensional laboratory coordinates (x, y,, converted to a cylindrical coordinate system (r, 0, on the following definitions (Fig 2). (1) (except the apical and basal reference markers) was plotted 1, and apical against longitudinal distance from the apex; linear regression 112, H23, and of 0 with respect to z provided the slope of this relation in rads oss-sectional per centimeter, which defined global LV chamber twist (Fig 3).…”

“…During diastole, there is an initial rapid clockwise untwisting that starts before mitral valve opening17 and continues during the first 15% to 20% of LV filling; this is followed by a more gradual untwist during the remainder of diastole when the bulk of filling occurs. Many reports suggest that ventricular torsion and global twist may play a role in the storage of potential energy and its subsequent release as elastic recoil during very early diastole, which helps the ventricle fill vis a fronte.5 15,17,20,30,[33][34][35] The concept of the ventricle helping itself to fill is not a new one, as Galen first noted that the heart during diastole ". .…”

“…Hansen et al16 demonstrated in human transplants that maximal regional LV torsional deformation during systole was insensitive to alterations in preload and afterload but increased with enhanced contractile state in a regionally heterogeneous manner. Rademakers 16,[18][19][20] Three markers were placed on the anterior wall along the left anterior descending coronary artery, three in the inferior wall along the posterior descending artery, and three along the lateral obtuse margin midway between the anterior and posterior markers. Two markers were placed into the interventricular septum at the basal and midventricular level through the tricuspid valve, and the final marker was placed at the apex.…”

Left Ventricular Torsion in Patients With Secundum Atrial Septal Defect

“…[8][9][10] Recently, assessment of LV rotation has become an important approach for quantifying LV function. [11][12][13][14][15][16][17][18][19][20][21][22][23][24] However, to the best of our knowledge there are no data available to date on the impact of RV volume overload on LV twist in patients with ASD. The recent development of 2-dimensional (D) ultrasound speckle tracking imaging (STI) has allowed LV torsional deformation to be evaluated noninvasively with validation against sonomicrometry and tagged magnetic resonance imaging (MRI).…”