**Sophie Kussauer, Robert David \* and Heiko Lemcke**

Department Cardiac Surgery, Medical Center, University of Rostock, 18057 Rostock, Germany; Sophie.Kussauer@med.uni-rostock.de (S.K.); Heiko.Lemcke@med.uni-rostock.de (H.L.) **\*** Correspondence: Robert.David@med.uni-rostock.de; Tel.: +49-381-4988973

Received: 25 September 2019; Accepted: 23 October 2019; Published: 28 October 2019

**Abstract:** Human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CM) have been intensively used in drug development and disease modeling. Since iPSC-cardiomyocyte (CM) was first generated, their characterization has become a major focus of research. Multi-/micro-electrode array (MEA) systems provide a non-invasive user-friendly platform for detailed electrophysiological analysis of iPSC cardiomyocytes including drug testing to identify potential targets and the assessment of proarrhythmic risk. Here, we provide a systematical overview about the physiological and technical background of micro-electrode array measurements of iPSC-CM. We introduce the similarities and differences between action- and field potential and the advantages and drawbacks of MEA technology. In addition, we present current studies focusing on proarrhythmic side effects of novel and established compounds combining MEA systems and iPSC-CM. MEA technology will help to open a new gateway for novel therapies in cardiovascular diseases while reducing animal experiments at the same time.

**Keywords:** cardiomyocytes; multi-electrode-array; micro-electrode-array; MEA; drug/toxicity screening; field potential
