A study to compare 2 methods of inserting a pulmonary artery catheter in high risk cardiac surgical patients.

INTERVENTION: All high risk cardiac surgical patients who require a pulmonary artery catheter (PAC) will have a PAC inserted by using video flouroscopy (directly screening of the catheter by vision into the pulmonary artery), or by conventional pressure wave form analysis (i.e floating the catheter into the pulmonary artery by using the pressure wave form trace as the catheter traverses through the superior vena cava into the right atrium into the right ventricle and then in to the pulmonary artery. The duraration of the intervention will be for the insertion of the PAC only. This will take approximately 30 seconds to 15 minutes, depending of the difficulty. CONDITION: High risk cardiac surgical patients Mitral valve disease with severe pulmonary hypertension Severe left ventricular systolic dysfunction Severe tricuspic regurgitation PRIMARY OUTCOME: Time in seconds to float the pulmonary artery catheter SECONDARY OUTCOME: Electrocardiographic rhythm disturbances Final positioning and exact catheter location in the pulmonary artery (recorded with transoesophageal echocardiography) Malposition or coiling of the catheter in the atrium or ventricle. This outcome will be assessed intraoperatively with transoesophageal echocardiography, and postoperatively with a chest radiograph performed on arrival in the Intensive Care Unit. Both these modalities will be able to assess malposition and/or coiling of the pulmonary artery catheter. Number of attempts at floatation. An attempt is defined as withdrawing the catheter back into the superior vena cava or right atrium INCLUSION CRITERIA: 1. Poor left ventricular function defined as ejection fraction < 35% 2. Low cardiac output syndromes: cardiac index < 1.5 l/min 3. Cardiac surgery for mitral valve disease with severe pulmonary hypertension (Mean PAP > 40mmHg) 4. Severe tricuspid insufficiency 5. Floating the catheter from a left internal jugular or left subclavian vein