Electrocardiographic Lead Systems: The Hexaxial Frontal Plane Reference System to Estimate Electrical Axis
Electrocardiographic lead systems: The hexaxial frontal plane reference system to estimate electrical axis. Determine leads in which QRS deflections are maximum and minimum. For example, a maximum positive QRS in I which is isoelectric in aVF is oriented to 0°. Normal axis ranges from -30° to +90°. An axis >+90° is right-axis deviation and <30° is left-axis deviation.