Abstract 18052: Concentric Tissue Geometry Decreases the Likelihood of Inducing Reentrant Spiral Waves
Introduction: The anisotropic structure of the heart leads to directional differences in conduction velocity that can be important in the initiation and maintenance of reentrant tachyarrhythmias.
Hypothesis: The goal of this work was to synthesize different anisotropic tissue structures in a cell culture system and to determine how those structures influence impulse propagation and reentry dynamics. We predicted that creating anisotropic structures different from the well-studied parallel/linear structure would result in patterns that have lower spiral wave induction pacing rates and would be easier to induce than the linear pattern.
Methods: Neonatal rat ventricular myocytes (NRVMs) were grown in linear, concentric and starburst patterns using microcontact printing.
Results: Cells on the different patterns were similar to one another and to those grown in isotropic monolayers in terms of confluency, morphology, connexin43 expression, and action potential duration. However, conduction velocity varied strongly with direction, and stable reentrant spiral waves lasting over one hour could be induced by rapid pacing. Starburst patterns, having the least parallel anisotropy, had the lowest induction pacing rate of 3-3.5 Hz (n=7) and were easiest to induce, followed by linear patterns with induction pacing rates of 4-5 Hz (n=7). Surprisingly, concentric patterns had the highest induction pacing rates of 5.6 Hz (n=7), and were very difficult to induce. In fact, pacing concentric patterns more than 0.1 Hz above or below 5.6 Hz would not induce reentry in our cultures. Furthermore, the spread and dynamics of the spiral waves differed markedly among the different anisotropic structures.
Conclusions: The type of anisotropic structure can have a strong influence in the genesis of stable reentrant waves.
Author Disclosures: J.M. Molitoris: None. R.B. Sekar: None. L. Tung: None.
- © 2016 by American Heart Association, Inc.