The effect of surgical revascularization on improving survival has been most clearly demonstrated in patients with both extensive CAD and LV dysfunc- Such patients should undergo testing to iden- tify the severity and extent of ischemia and should in general be referred for coronary angiography. In selected patients with appropriate anatomy, PCI has been used.23,568 In patients who have already undergone CABG or in whom the anatomy is not favorable for CABG, PCI has been performed using CPG- based PCI performance strategies if specific targeted areas that are amenable to PCI can be identified.26 If there is a large amount of ischemic territory and very poor LV function, per- cutaneous ventricular assist devices or, in less severe cases, an IABP can be used for support during the procedure.266,569 573 See Online Data Supplement 25 for additional information on HF. Ventricular arrhythmias are common early after onset of NSTE-ACS, and not all require intervention. The mechanisms for these arrhythmias include continuing ischemia, hemody- namic and electrolyte abnormalities, reentry, and enhanced automaticity. Approximately 5% to 10% of hospitalized patients may develop ventricular tachycardia (VT)/ventricular fibrillation (VF), usually within 48 hours of presentation.574 The incidence of VF in otherwise uncomplicated AMI appears to have decreased within the past few years from >4% to <2%, of which 59% of patients had non Q-wave MI.574 A study of 277 consecutive patients with NSTE-ACS who under- went cardiac catheterization within 48 hours found VT/VF occurring in 7.6% of patients, 60% of which developed within 48 hours after admission.575 Risk factors for VT/VF include HF, hypotension, tachycardia, shock, and low TIMI flow grade. Treatment consists of immediate defibrillation or Table 11. 