If improvement of symptoms is not achieved, an emergent surgical sternotomy should be performed. Low Cardiac Output/Cardiogenic Shock Intraprocedural circulatory depression may occur in up to 20% of patients during implantation. Cardiac

depression with low cardiac output may follow long periods of rapid pacing or may be the consequence of inadequate coronary perfusion due to low intra-aortic pressure. Coronary perfusion may also be impaired when the remaining aortic valve orifice is partially or completely occluded Inhibitors,research,lifescience,medical during the placement of the catheter-mounted valve. Another reason for cardiac depression may be the sudden onset of severe bradycardia or third-degree AV block following balloon dilatation of the aortic valve or deployment of the valve prostheses. Furthermore, Inhibitors,research,lifescience,medical obstruction of coronary ostia or severe AR after balloon dilatation or after deployment of the valve prosthesis may also cause severe cardiac depression. To prevent or react adequately to this complication, it is mandatory that anesthesiologists keep in close communication with the implant team. In cases of bradycardia or sudden onset

of third-degree AV block, ventricular pacing may quickly improve the circulatory condition. In other cases, if mild hypotension does not resolve spontaneously, Inhibitors,research,lifescience,medical it may easily be treated with bolus injections of catecholamines or a continuous infusion of low-dose dopamine or dobutamine. In cases of a more severe blood pressure drop, the management of norepinephrine, milrinone and/or levosimendan should be determined by the anesthesiologist. Intraprocedural ventricular fibrillation is treated by electrical conversion Inhibitors,research,lifescience,medical followed by cardiopulmonary resuscitation. If those measures do not help to restore circulation, emergency institution of http://www.selleckchem.com/products/SB-431542.html extracorporeal circulation is the only safe rescue therapy. In those cases, implantation of the valve should be continued

during extracorporeal circulation so that Inhibitors,research,lifescience,medical the patient is weaned with the valve prostheses already in place. Coronary Obstruction Coronary obstruction during Cytidine deaminase implantation is a rare entity, occurring in less than 1% of patients. The reasons for this potentially catastrophic event include (1) displacement of calcium deposits or large native aortic valve leaflets in front of the coronary ostia during valve deployment; (2) embolization of calcium debris into one of the coronary arteries; (3) aortic dissection with continuity of the rupture into the intima of one of the coronary ostia with resultant obstruction; and (4) a valve prosthesis that is implanted too high. In addition, coronary air embolism can lead to myocardial ischemia. The first reason described may be more frequent in the setting of a low-lying coronary artery and small coronary sinus diameters and may lead to subacute coronary occlusion.