- 70-year-old female, one month in ICU, with failure to wean following elective surgery for MVR and tricuspid valve annuloplasty. Clinical findings included ventricular pacing with cannon a waves, parasternal heave,systolic murmur at the left sternal edge and mid-diastolic murmur at the apex, tender hepatomegaly and the presence of a tracheostomy and a midline sternotomy scar. Candidates were told that she had difficulty weaning from ventilatory support following TV annuloplasty and MVR 4 weeks previously and were asked to examine her focussing on the cardio-respiratory system. Discussion points included reasons for failure to wean post MVR, mechanism of cannon a waves and management issues specific to the case.