In leads I, II, III, aVL, and V4 through V6, the deflection of the QRS is?

The QRS complex represents the depolarization of the ventricles in an electrocardiogram, and its deflection can indicate how the electrical activity is oriented in relation to the leads placed on the body. In standard limb leads I, II, III, and leads aVL, V4, V5, and V6, the typical deflection of the QRS complex is upright.

This is due to the positive polarity of these leads in relation to the direction of the ventricular depolarization wave. When the electrical impulse travels towards a positive lead, the deflection of the QRS complex is seen as upright. In the case of leads I and II, both are oriented along the frontal plane of the body, capturing the leftward and inferior depolarization of the ventricles, which is a dominant vector in a healthy heart.

In addition, leads V4, V5, and V6 are positioned over the left side of the heart, directly capturing the strong electrical forces that arise from left ventricular depolarization. This results in a positive (upright) QRS complex in these leads, confirming that the heart’s electrical activity is aligned positively to these electrodes. Therefore, the appropriate response for the deflection of the QRS