Making a silk purse out of a sow's ear.

recise information regarding prolongation of cardiac repoarization by non-cardiac drugs has become a highly valued ommodity. The reason for this emphasis is that we now now that chemical entities that have the propensity to rolong repolarization may, under some set of circumtances, cause a particularly malignant form of ventricular rrhythmia called Torsade de Pointes (TdP). With rare xceptions, a relationship appears to exist between the agnitude of prolongation of ventricular refractoriness and he risk of developing TdP. To this point in time, the linical parameter that has been used to measure changes in efractoriness has been the QT interval. To some extent, its se is ironic because there has been general consensus