Many medications are known to prolong the QTc interval, which is a marker for the potential of ventricular arrhythmia and a risk of sudden death. The QTc represents electrical depolarization and polarization of the ventricles and is measured with full EKG measurements, which is time-consuming and costly. As a result, the QTc is not monitored as closely as recommended. InstaQTc is a simple hand-held device that provides the QTc interval using only 3 electrodes, thereby enabling clinicians to efficiently monitor patients at risk for prolonged QTc interval.