AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram: Part IV: The ST Segment, T and U Waves, and the QT Interval

February 19, 2009—The present article is the fourth in a series of six documents focused on providing current guidelines for the standardization and interpretation of the electrocardiogram (ECG). Several issues relative to the measurement, description, and interpretation of ST segment, T and U waves, and QT interval are addressed.