loosely refers to the hearts electrical axis when this is directed at approximately 0°. As a cardiac electrical position, recognized in the electrocardiogram when the QRS complex in lead aVL resembles V6 whereas that in aVF is small algebraically or absolutely.
Farlex Partner Medical Dictionary © Farlex 2012
sem·i·hor·i·zon·tal heart(sem'ē-hōr'i-zon'tăl hahrt)
Refers to the heart's electrical axis when this is directed at approximately 0 degrees.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012