input: The following are multiple choice questions (with answers) about medical knowledge.   The purpose of this study is to evaluate right ventricular (RV) volume and function after pulmonary valve replacement (PVR) and to address the issue of optimal surgical timing in these patients. Chronic pulmonary regurgitation (PR) following repair of tetralogy of Fallot (TOF) leads to RV dilation and an increased incidence of sudden cardiac death in adult patients. We studied 25 consecutive adult patients who underwent PVR for significant PR late after repair of TOF. Radionuclide angiography was performed in all at a mean of 8.2 months (+/- 8 months) before PVR and repeated at a mean of 28.0 months (+/- 22.8 months) after the operation. Right ventricular (RV) end-systolic volume (RVESV), RV end-diastolic volume (RVEDV) and RV ejection fraction (RVEF) were measured. Mean RVEDV, RVESV and RVEF remained unchanged after PVR (227.1 ml versus 214.9 ml, p = 0.74; 157.4 ml versus 155.4 ml, p = 0.94; 35.6% versus 34.7%, p = 0.78, respectively). Of the 10 patients with RVEF>or = 0.40 before PVR, 5 patients (50%) maintained a RVEF>or = 0.40 following PVR, whereas only 2 out of 15 patients (13%) with pre-operative values<0.40 reached an RVEF>or = 0.40 postoperatively (p<0.001).   **Question:** Pulmonary valve replacement in adults late after repair of tetralogy of fallot: are we operating too late?   (A) Yes   (B) No   (C) Maybe
output: ['(A) Yes <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Yes  (B) No  (C) Maybe <> possible answers', 'The purpose of this study is to evaluate right ventricular (RV) volume and function after pulmonary valve replacement (PVR) and to address the issue of optimal surgical timing in these patients. Chronic pulmonary regurgitation (PR) following repair of tetralogy of Fallot (TOF) leads to RV dilation and an increased incidence of sudden cardiac death in adult patients. We studied 25 consecutive adult patients who underwent PVR for significant PR late after repair of TOF. Radionuclide angiography was performed in all at a mean of 8.2 months (+/- 8 months) before PVR and repeated at a mean of 28.0 months (+/- 22.8 months) after the operation. Right ventricular (RV) end-systolic volume (RVESV), RV end-diastolic volume (RVEDV) and RV ejection fraction (RVEF) were measured. Mean RVEDV, RVESV and RVEF remained unchanged after PVR (227.1 ml versus 214.9 ml, p = 0.74; 157.4 ml versus 155.4 ml, p = 0.94; 35.6% versus 34.7%, p = 0.78, respectively). Of the 10 patients with RVEF>or = 0.40 before PVR, 5 patients (50%) maintained a RVEF>or = 0.40 following PVR, whereas only 2 out of 15 patients (13%) with pre-operative values<0.40 reached an RVEF>or = 0.40 postoperatively (p<0.001). \n   Pulmonary valve replacement in adults late after repair of tetralogy of fallot: are we operating too late? <> context']