extraventricular

ex·tra·ven·tric·u·lar

(eks'tră-ven-trik'yū-lăr), Outside any ventricle, especially of one of the ventricles of the heart.

extraventricular

(ĕks″tră-vĕn-trĭk′ū-lăr) [″ + ventriculus, little belly] Outside any ventricle, esp. one of the heart.