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Abstract #0233

Correlation between Spatial Differences in Action Potential Duration & Myocardial Dysfunction in Transgenic LQT2 Rabbits

Bernd Jung1, Daniela Foell2, Corinna Lang2, David Ziupa2, Gerlind Franke2, Stefanie Perez Feliz2, Michael Brunner2, Gideon Koren3, Manfred Zehender2, Katja E. Odening2

1Radiology, Medical Physics, University Medical Center, Freiburg, Germany; 2Cardiology, University Medical Center, Freiburg, Germany; 3Cardiovascular Research Center, Division of Cardiology, Rhode Island Hospital, Providence, United States

Transgenic LQT2 rabbits and wildtype controls were subjected to in vivo phase contrast MRI in a 1.5T MR-system to assess regional myocardial velocities in the LV (AHA 16-segment model). The same rabbits’ hearts were subsequently Langendorff-perfused and subjected to ex vivo epicardial monophasic action potential measurements to assess APD in the corresponding segments. Prolongation of cardiac repolarization and increased dispersion of APD lead to a globally and regionally impaired systolic and diastolic function in transgenic LQT2 rabbits. Moreover, regional APDs correlate with regional peak diastolic velocities indicating that Long-QT syndrome is not purely an electrical but rather an electromechanical disorder.