Lewis index
The Lewis index (after the British cardiologist Sir Thomas Lewis , 1881–1945) is a diagnostic EKG symbol for left ventricular hypertrophy (enlargement) of the heart muscle and is determined using the limb leads according to Einthoven . The sign is relatively insecure, but can be used as a hint. The suspicion can be supported by a positive Sokolow-Lyon index .
The index for the enlargement of the left heart is calculated using the following formula based on the amplitude levels in mV:
R I + S III - R III - S I
If the value is greater than or equal to 1.7 mV, left ventricular hypertrophy can be assumed.
literature
- Schuster, Trappe: EKG course for Isabel . 3. Edition. Thieme, Stuttgart 2001, ISBN 3-13-127283-X , p. 94 ff .