Beschreibung:
<jats:title>Abstract</jats:title><jats:p><jats:bold>We have developed an automatic left ventricular assist device (LVAD) system which can maintain the normal circulation irrespective of severity of the LV failure (LVF) and can restore the failing heart by decreasing the bypass flow (BF) through the LVAD as the heart recovers. The main parts of our control‐drive unit are an automatic ECG synchronization system and an automatic level control system for left atrial pressure (LAP) and total flow (TF). Profound LVF was induced by complete interception of blood supply (myocardial infarction: MI) to the extent of 50% (5 goats), 70–80% (6 goats), and 80–90% (3 goats) of the LV free wall. The air‐driven, diaphragm‐type pump was implanted between the left atrium and aorta. At the beginning of LVAD pumping, BF tended to be high to keep LAP at the preset level (0–5 mm Hg) and to maintain TF at a somewhat higher level (100–130 ml/kg per min). During the recovering stage from LVF, the preset level of LAP was gradually raised. When cardiac output exceeded 90–100 ml/kg per min, LVAD was removed. The 50% MI group recovered between 17 hr and 3 days, the 70–80% MI group between 6 and 16 days after the onset of LVAD pumping. However, the 80–90% MI group could not recover because of intractable ventricular fibrillation. This LVAD system was applied in 1 patient who fell into postcardiotomy profound LVF. The patient's entire circulation was maintained at normal levels by the LVAD during a 14‐day period. The failed heart gradually recovered and the pump was successfully removed. We believe that the decompression of LV at the beginning will prevent overextension of impaired myocardium and simultaneously accelerate the solid scar formation. Gradual increase of LV work will promote the compensation ability of the residual myocardium</jats:bold>.</jats:p>