New Methods in Cardiovascular Biology Simultaneous Voltage and Calcium Mapping of Genetically Purified Human Induced Pluripotent Stem Cell–Derived

Rationale: Human induced pluripotent stem cell–derived cardiomyocytes (iPSC-CMs) offer a powerful in vitro tool to investigate disease mechanisms and to perform patient-specific drug screening. To date, electrophysio-logical analysis of iPSC-CMs has been limited to single-cell recordings or low-resolution microelectrode array mapping of small cardiomyocyte aggregates. New methods of generating and optically mapping impulse propagation of large human iPSC-CM cardiac monolayers are needed. Objective: Our first aim was to develop an imaging platform with versatility for multiparameter electrophysio-logical mapping of cardiac preparations, including human iPSC-CM monolayers. Our second aim was to create large electrically coupled human iPSC-CM monolayers for simultaneous action potential and calcium wave propagation measurements. Methods and Results: A fluorescence imaging platform based on electronically controlled light-emitting diode illumination, a multiband emission filter, and single camera sensor was developed and utilized to monitor simultaneously action potential and intracellular calcium wave propagation in cardiac preparations. Multiple, large-diameter (>1 cm), electrically coupled human cardiac monolayers were then generated that propagated action potentials and calcium waves at velocities similar to those commonly observed in rodent cardiac monolayers. Conclusions: The multiparametric imaging system presented here offers a scalable enabling technology t