Hello guys I hope this ppt will help you to understand what is Hexaxial reference system in ECG[ELECTRO CARDIO GRAPHY]
WHAT IS ECG?
WHAT IS HEXAXIAL REFERENCE SYSTEM?
2. TRIAXIAL REFERENCE SYSTEM
Standard lead
• The lead axes of the three standard leads form an equilateral triangle.
• This constitutes Einthoven's equilateral triangle, each angle of the triangle
being 60°
3.
4. TRIAXIAL REFERENCE SYSTEM
• The lead axes of Einthoven's triangle may be transposed so
that they bisect each other while maintaining their orientation.
• These three lead axes thus form a triaxial reference system
with each lead axis being theoretically separated from the
other by 60°
5.
6.
7. TRIAXIAL AND HEXAXIAL SYSTEM
Unipolar lead
The unipolar extremity leads are so constructed that their lead axes
geometrically bisect the angles of the equilateral triangle formed by the
standard leads
• Each electrode of these unipolar leads is a positive electrode.
• These leads, too, may be transposed so that they bisect each other while
maintaining their orientation
8. TRIAXIAL AND HEXAXIAL SYSTEM
• They also form a triaxial reference system with each lead axis separated
from the other by 60°
• When these two triaxial reference systems are combined and
superimposed upon each other, they form a hex-axial reference system
• Each lead axis is then separated from its two neighbouring axes by 30°
• This hexaxial reference system is used for graphing the mean manifest
frontal plane electrical axes.
9.
10. HEXAXIAL SYSTEM
• Naming the degrees
• By an irrational and confusing convention, the degrees in the
upper hemisphere of the hexaxial reference system are
labelled negative degrees, whereas those in the lower half are
labelled positive degrees.
11. HEXAXIAL SYSTEM
• Thus, beginning with the positive pole of standard lead I,
which is labelled 0°, and progressing clockwise, the leads are
labelled sequentially +30°, +60°, +90°, +120°, +150° and
+180°.
• Beginning at 0° and progressing counterclockwise, the leads
are labelled sequentially -30°, 60°, 90°, -120°, -150° and -
180°. The 180° position may be termed + or - 180°.
