Relation between longitudinal, circumferential, and oblique shortening and torsional deformation in the left ventricle of the transplanted human heart.

Abstract

The present study was designed to investigate the anisotropy of systolic chord shortening hi the lateral, inferior, septal, and anterior regions of the human left ventricle. At the time of surgery, 12 miniature radiopaque markers were implanted into the left ventricular midwall of the donor heart in 15 cardiac transplant recipients. Postoperative biplane cineradiograms were computeranalyzed to yield the three-dimensional coordinates of these markers at 16.7-msec intervals. In each of the four left ventricular regions, chords were constructed from a central marker to outlying markers, and the percent systolic shortening of each chord was calculated. In each region, chord angles were measured with respect to the circumferential direction (positive angles counterclockwise) and each chord was assigned to one of four angular groups: I. oblique, -45±22.5° or 135±22.5°; II. circumferential, 0±22.5° or 180±22.5°; i n . oblique, 45±22.5° or -135±22.5°; or IV. longitudinal, 90±22.5° or -90±22.5°. In the lateral, inferior, and septal regions, respectively, systolic shortening (mean±SD %) was significantly greater in Group I chords (19±5%, 17±5%, and 15±4%) than those in Group O (15±5%, 12±4%, and 11±4%), Group m (12±4%, 12±5%, and 11±4%), or Group IV (13±5%, 13±6%, and 12±5%). The anterior region was unique hi exhibiting equal shortening in both Group I and Group II chords (16±5%), although the shortening of these chords was significantly greater than that of Group III and Group IV (12±5%) hi this region. A cylindrical mathematical model was developed to relate longitudinal, circumferential, and oblique systolic shortening to torsional deformation about the long axis of the left ventricle. Torsional deformations measured in these 15 hearts were of sufficient magnitude and correct sense to agree with model predictions. These data suggest that torsional deformations of the left ventricle are of fundamental importance in Unking the one-dimensional contraction of the helically wound myocytes to the three-dimensional anisotropic systolic shortening encountered in the transplanted human heart. (Circulation Research 1989;64:915-927) M ore than two centuries have passed since Senac 1 first observed that epicardial and endocardial fibers were aligned longitudinally and midwall fibers were aligned circumfer-

Echocardiographic evaluation of diastolic heart failure

“…Contraction of these oblique and spirally orientated fibres causes “torsion” such that when viewed from the apex, systolic contraction of the ventricle is characterised by the counterclockwise rotation of the apex and clockwise rotation of the base 146 . During isovolumic contraction, brief apical clockwise rotation occurs that reverses rapidly becoming counterclockwise during LV ejection 147 , 148 , followed by untwisting (clockwise rotation) during early diastole. In contrast, rotation of the base is lower in magnitude and opposite in direction.…”

Strain‐encoded MRI to evaluate normal left ventricular function and timing of contraction at 3.0 Tesla

“…With strain data based on implanted markers (11,12) and in previous studies with MR tagging (14 -19), some normal human heart strain values have been calculated. Ingels et al (12) implanted arrays of tantalum screws in 15 transplanted hearts and found the longitudinal peak strain at the midventricular level to range from 12% Ϯ 5% to 13% Ϯ 6% compared with 16.4% Ϯ 1.6% to 19.2% Ϯ 1.6% in our study, and the peak circumferential strain at the middle ventricular level to range from 15% Ϯ 4% to 19% Ϯ 5% compared with the 16% Ϯ 1.7% to 20.8% Ϯ 2.7% calculated in this study. The strain values in the study by Ingels et al (12) were qualitatively similar but slightly lower in magnitude than those in the present study.…”

“…Ingels et al (12) implanted arrays of tantalum screws in 15 transplanted hearts and found the longitudinal peak strain at the midventricular level to range from 12% Ϯ 5% to 13% Ϯ 6% compared with 16.4% Ϯ 1.6% to 19.2% Ϯ 1.6% in our study, and the peak circumferential strain at the middle ventricular level to range from 15% Ϯ 4% to 19% Ϯ 5% compared with the 16% Ϯ 1.7% to 20.8% Ϯ 2.7% calculated in this study. The strain values in the study by Ingels et al (12) were qualitatively similar but slightly lower in magnitude than those in the present study. Limitations of the implantation method, such as changes from surgical transplantation, presence of metal helices in myocardium, and low spatial resolution, may account for these differences.…”

Relation between torsion and cross-sectional area change in the human left ventricle

“…In several reports torsion and contraction were investigated separately (Buchalter et d., 1994;Gibbons Kroeker et al, 1993;Hansen et al, 1991;Ingels et al, 1989;Ohayon and Chadwick, 1988;Rademakers et al, 1992;Young et ul., 1994). Arts et al (1984) measured the relation between torsion and contraction echographically in dogs.…”