History of Electrocardiography, Einthoven law, Einthoven triangle, additional leads,vectorcardiography

1. BASIC
ELECTROCARDIOGRAPHY
Dr. N.PRAVEEN
MD,DM

2. Waller recorded electrical
acitivity from human heart
Willem Einthoven built string
galvanometer based 3 lead EKG
machine
Wilson invented
central terminal
Precordial leads
were born
Carlo Matteucci
Electrical activity from the heart of a frog
1842
1887
1901
1934-38
Goldberg used the
central terminal
with augmentation
1942 AHA Standardized
12 lead ECG
1954
EVOLUTION
OF
ELECTROCARDIOGRAPHY

5. Einthoven’s law
Helpful rule to remember to detect instances in which the technician has attached the electrodes to the wrong limbs.

6. • For unipolar leads, multiple electrodes are connected together to
represent the negative end of the bipolar pair - reference electrode.
• The single electrode serving as the positive input - exploring electrode,
• The concerned lead records the potential difference between the two.

7. Unipolar limb leads
• With the exploring electrode on one limb, the potential at the root of
the explored limb is recorded exclusively.

10. Additional Leads

12. Ventricular depolarization
• Occurs in three successive steps -- generation of three vectors
( the expression of three dipoles)
• Ventricular depolarization starts at three different sites in the LV –
the areas of the anterior and posterior papillary muscles and
midseptal area.
• 1 – rightward, anterior, inferior
• 2 - leftward, posterior, inferior
• 3 - rightward, anterior, superior

13. RIGHT
LEFT
ANTERIOR
POSTERIOR

14. Take home message
 The two electrodes to be misplaced frequently are the RA (Red) and LA
(Yellow).
 Einthoven law states Lead II = Lead I + Lead III.
 Right sided leads are useful for detection of RVMI.
 Posterior leads are useful for detection of posterior wall STEMI.
 Vectorcardiography is depiction of the vectors in loops rather than waves and
complexes.
 Scalar ECG gives almost every information obtained by vectorcardiography.

15. Thank you