**4. Ventricular arrhythmia tolerance and Fontan-type circulation**

LVAD population has a better tolerance for sustained VD, including ventricular fibrillation (VF) than the non-LVAD population, most likely due to the "Fontan-type circulation" phenomena. This population has the same ability to withstand insults as patients with congenital heart diseases and Fontan-type circulation [3] described by Fontan and Baudet in 1971 to palliate tricuspid atresia relying on central venous circulation enabling blood to be directed toward the RV in the absence of pulmonary hypertension.

In patients with LVAD, the right ventricle behaves as a passive corridor driving blood from right to left if adequate preload condition is met. High pulmonary pressure or low central venous pressure is associated with more difficulties to remain stable once VD appears [23, 24].

Sims et al. [25] described how a continuous flow-LVAD could avoid collapse in a patient with sustained ventricular fibrillation over 12 hours when an implantable defibrillator was not able to terminate arrhythmia and external defibrillation was required, due to a correct preload to the LV and normal or low pulmonary resistances. The same findings were described by Busch et al. and Smith et al. [26, 27].
