Ventricular function after operation for transposition of the great arteries with special reference to myocardial deformation
Transposition of the great arteries (TGA) is the second most common cyanotic congenital heart defect. With advances in surgical treatment, more patients survive into adulthood and constitute a growing patient population, requiring regular follow-up including evaluation of myocardial function.
The aim of this thesis in cardiology was to describe ventricular function in TGA patients operated with atrial or arterial switch, with special emphasis on myocardial deformation described in terms of longitudinal and circumferential contraction and ventricular torsion.
Patients operated with atrial switch (n=14) and arterial switch (n=22) were studied using tissue Doppler and speckle tracking echocardiography, respectively, as well as magnetic resonance imaging.
The systemic right ventricle of the atrial switch-operated patients and the left ventricle of the arterial switch-operated patients displayed a contraction pattern similar to the normal left ventricle with predominant circumferential over longitudinal shortening. These findings suggest that the ventricular contraction pattern in TGA patients is mainly the result of loading conditions.
However, despite normal measures of global ventricular function, myocardial deformation imaging revealed signs of incipient myocardial dysfunction in both atrial and arterial switch-operated patients, with more pronounced reductions in deformation variables in the atrial switch-operated group.
The findings of this thesis suggest that analysis of myocardial deformation variables is of value in operated TGA patients, both in studying ventricular physiology and in assessing possible ventricular dysfunction not disclosed by standard measures of ventricular function.
List of papers. Papers 1-3 are removed from the thesis due to copyright restrictions.
Pettersen E, Helle-Valle T, Edvardsen T, Lindberg H, Smith HJ, Smevik B, Smiseth OA, Andersen K.: Contraction Pattern of the Systemic Right Ventricle - Shift from Longitudinal to Circumferential Shortening and Absent Global Ventricular Torsion.
Journal of the American College of Cardiology 2007; 49:2450-6.
Pettersen E, Lindberg H, Smith HJ, Smevik B, Edvardsen T, Smiseth OA, Andersen K.: Left Ventricular Function in Patients with Transposition of the Great Arteries Operated with Atrial Switch.
Pediatric Cardiology 2008; 29:597-603.
Pettersen E, Fredriksen PM, Urheim S, Thaulow E, Smith HJ, Smevik B, Smiseth OA, Andersen K.: Ventricular Function in Patients with Transposition of the Great Arteries Operated with Arterial Switch.
American Journal of Cardiology 2009; 104:583-9.