A simulation study of Torsade de Pointes with M cells.
Recent studies have reported the relation between Torsade de Pointes (TdP) and midmyocardial (M) cell function associated with long QT syndrome. To investigate this relation, we conducted a simulation study with a three-dimensional (3D) heart model incorporating M cells in the anterolateral areas of the model. Parameters of premature cycle-length dependent shortening of action potential duration (APD) and conduction velocity for the M cells were adjusted to induce tachyarrhythmias of TdP type. Under a basic pacing cycle length of 1,000 msec at the sinus node, four successive premature beats of 160-ms interval were generated 300 ms after the first sinus pacing. Setting lower conduction velocity and longer APD to M cells induced sustained TdP-like tachyarrhythmia resembling ECG findings. TdP could not be induced without the presence of M cells. This study suggests that TdP might be caused by reentry around M cells and dispersive refractory areas due to prolonged APD and slow conduction velocity.
Okazaki
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O
Nora Eccles Harrison CVRTI, University of Utah, Salt Lake City 84112-5000, USA.
Wei
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D
Harumi
K
K
D000200:Action Potentials; D016880:Anisotropy; D003198:Computer Simulation; D006339:Heart Rate; D006352:Heart Ventricles / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D008133:Long QT Syndrome / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D008955:Models, Cardiovascular; D015203:Reproducibility of Results; D016171:Torsades de Pointes / Q000150:complications / Q000473:pathology / Q000503:physiopathology*