The invention provides a culture of patterned cardiomyocytes, the culture including a support substrate bearing a multielectrode array, a negative surface resistant to cell attachment and deposited on the support substrate covering the multi-electrode array, a pattern ablated on the negative surface, a positive surface promoting cell attachment deposited on the pattern ablated on the negative surface; and cardiomyocytes adherent to the positive surface and growing aligned along the pattern ablated on the negative surface. The invention also includes a method of making the culture of patterned cardiomyocytes and a method of in vitro method of testing the effect of a compound on cardiac function by measuring electrical output from the patterned cardiomyocytes.