Final answer:
Right axis deviation on an ECG indicates the QRS vector lies between +90° and +180°, showing the heart's depolarization is directed abnormally rightward.
Step-by-step explanation:
In Right axis deviation, the QRS vector typically lies between +90° and +180°. This condition can be identified on an electrocardiogram (ECG) where the direction of the heart's electrical depolarization is abnormally oriented to the right side of the heart. This deviation can be observed by analyzing the leads on an ECG: Lead I will have a predominantly negative QRS complex, and Lead II or Lead III will show a predominantly positive QRS complex, indicating the direction of the electrical vector toward the right side of the heart.