Abstract: Described herein are methods for evaluating a cardiac preparation. The methods involve providing at least one sample comprising one or more cardiac cells, pacing the one or more cardiac cells at two or more fixed rates; and measuring a fixed response of the one or more cardiac cells at each of the two or more fixed rates. Also described herein are methods for evaluating the cardiac effect of a compound. The methods involve providing at least one sample comprising one or more cardiac cells; contacting each sample with the compound; pacing the one or more cardiac cells at two or more fixed rates; and measuring a fixed response of the one or more cardiac cells to the compound at each of the two or more fixed rates.

Abstract: The present invention establishes a new standard for investigative studies of patient-specific, genetic cardiac diseases at a functional, tissue level by creating a novel platform for the study of cardiac related diseases, including cardiac conduction dysfunction, arrhythmias and depressed contractility for example. Provided herein are novel compositions of human engineered heart slices (EHS) formed from thin slices of decellularized cardiac tissue. Also included are compositions comprising a hybrid of decellularized tissue and organotypic organ slice technology. Intact mammalian hearts are precision cut to obtain thin slices in a range of thicknesses, decellularized, and seeded with various mammalian cells which can be from a variety of sources. Methods of investigation of many diseases and methods of use of these compositions for screening compounds for therapeutic purposes are also provided.