In the normal heart, the direction of the T wave vector in the frontal plane is similar to that of the QRS complex and, like the QRS vector, is located between 0 and +90 degrees. Most often it is between +45 and +60 degrees and the angle between the main QRS vector and the T wave vector (the QRS-T angle) is normally less than 60 degrees. Thus, the normal T wave should always be positive in leads I and II and negative in lead aVR. In the tracing shown here, the main QRS vector (the red arrow) is +26 degrees, the T wave vector (the yellow arrow) is +21 degrees and the QRS-T angle is only 5 degrees.