Patent ID: 8192929

Claim:
A method comprising: (i) providing a first and a second genetically modified cell that are either both cardiomyocytes or both mesenchymal stem cells (MSCs) comprising a nucleic acid construct, wherein the construct in the first cell comprises a gene that is expressed by the first cell, and the construct in the second cell does not comprise the gene; (ii) providing a first and a second cardiac syncytial cell; (iii) determining a baseline rhythm for the first and second cardiac syncytial cells in vitro; (iv) contacting the first cardiac syncytial cell with the first cell of step (i) and contacting the second cardiac syncytial cell with the second cell of step (i) in vitro; (v) determining the rhythm of the first and second cardiac syncytial cells after the contacting step (iv) in vitro; and (vi) identifying the first cell of step (i) as a cell that alters rhythm of a cardiac syncytial cell if the rhythm of the first cardiac syncytial cell determined in step (v) differs from its baseline rhythm determined in step (iii), and the rhythm of the second cardiac syncytial cell determined in step (v) does not differ from its baseline rhythm determined in step (iii).