Abstract: This invention provides for a method of inducing a current in the heart in a subject which comprises contacting a cell of the heart of a subject with a compound in a sufficient amount to induce a current in the cell of the heart of a subject. This invention also provides a method of treating a cardiac condition in a subject which comprises contacting a cell of the heart of the subject with a compound in an amount sufficient to increase the current expression of the cell, thereby treating the cardiac condition in the subject.

Abstract: This invention provides for a chamber and system designed for use in assaying drug effects on heart rate. The chamber consists of a series of wells, each 3 mm by 3 mm in inner diameter. Cardiac myocytes disaggregated from neonatal animals are plated onto the bottom of each well and grown under standard tissue culture conditions. The chamber holds from 24-96 such wells. When drugs are to be assayed, the cells in each well are loaded with a calcium sensitive dye and the beating rate in each is monitored with a photodiode. Drug is added in graded concentrations to each well, and equilibrated and effects on rate are observed. This construct permits use of a cell based bioassay for the study of drugs or agents that may alter cardiac rate. This invention can be used in high throughput screening of drugs to evaluate/predict their effects on cardiac rate and rhythm. Further provided for by this invention is a A vector which comprises a compound which encode an ion channel.