 All cardiac cannulae including the LV vent will be left in situ but clamped, patient weaned completely from the cardiopulmonary bypass and monitored for residual air by TEE TCD for 10 minutes continually. The LV vent will be re-opened whenever the residual air in the left heart exceeds grade II. The frequency of theses measures will be noted in the protocol. If the patient has by now achieved 36 Celsius core temperature, the heart will be decannulated and CPB removed. Otherwise CPB will be restarted and patient warmed to 36 Celsius before final weaning and decannulation. 