Heparinless total left heart bypass with induced ventricular fibrillation

A new technic of extracorporeal total left heart bypass without anticoagulation is described. Left atrial and ventricular cannulas, coated with PPG, drain the blood into a bladder pump which returns blood into the descending thoracic aorta, thus establishing total left heart bypass. In acute experiments, ventricular fibrillation was electrically induced and total left heart bypass was continued for one hour (nine dogs) or four hours (one dog), after which the heart was successfully defibrillated. Near normal systemic circulation was maintained during bypass, although there was no active driving force through the pulmonary circulation except for right atrial contraction. In survival experiments ten dogs were subjected to the same procedure for one to three hours. After defibrillation they were allowed to survive for two to four weeks. Eight were long-term survivors. One died because of a technical error and the other of atelectasis. In four other dogs an autogenous saphenous vein was successfully implanted between the ascending aorta and the circumflex coronary artery using a nonthrombogenic left heart bypass with ventricular fibrillation technic. There was minimal blood loss due to elimination of anticoagulants, and the elimination of an artificial oxygenator simplified the extracorporeal circulation system. During total left heart bypass with ventricular fibrillation, inspiratory pressures were maintained at 10 mm Hg. This study indicates (1) that total left heart bypass can maintain normal systemic circulation in dogs for up to four hours during ventricular fibrillation, and (2) that this technic may be applicable to simplify coronary artery bypass surgery.