Structure and torsion of the normal and situs inversus totalis cardiac left ventricle. I. Experimental data in humans.
Am J Physiol Heart Circ Physiol
; 295(1): H197-201, 2008 Jul.
Article
in En
| MEDLINE
| ID: mdl-18441201
ABSTRACT
In 1926, the famous American pediatric cardiologist, Dr. Helen B. Taussig, observed that in situs inversus totalis (SIT) main gross anatomical structures and the deep muscle bundles of the ventricles were a mirror image of the normal structure, while the direction of the superficial muscle bundles remained unchanged (H. B. Taussig, Bull Johns Hopkins Hosp 39 199-202, 1926). She and we wondered about the implication of this observation for left ventricular (LV) deformation in SIT. We used magnetic resonance tagging to obtain information on LV deformation, rotation, and torsion from a series of tagged images in five evenly distributed, parallel, short-axis sections of the heart of nine controls and eight persons with SIT without other structural (cardiac) defect. In the controls, during ejection, the apex rotated counterclockwise with respect to the base, when looking from the apex. Furthermore, the base-to-apex gradient in rotation (torsion) was negative and similar at all longitudinal levels of the LV. In SIT hearts, torsion was positive near the base, indicating mirrored myofiber orientations compared with the normal LV. Contrary to expectations, torsion in the apical regions of SIT LVs was as in normal ones, reflecting a normal internal myocardial architecture. The transition zone with zero torsion, found between the apex and base, suggests that the heart structure in SIT is essentially different from that in the normal heart. This provides a unique possibility to study regulatory mechanisms for myocardial fiber orientation and mechanical load, which has been dealt with in the companion paper by Kroon et al.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Situs Inversus
/
Ventricular Dysfunction, Left
/
Myocardium
Type of study:
Observational_studies
/
Prognostic_studies
Limits:
Adolescent
/
Adult
/
Aged
/
Child
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Am J Physiol Heart Circ Physiol
Journal subject:
CARDIOLOGIA
/
FISIOLOGIA
Year:
2008
Document type:
Article
Affiliation country:
Países Bajos
Publication country:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
/
US
/
USA