If defibrillation is unsuccess- ful in returning spontaneous circulation, respond- ers follow advanced cardiovascular life support 4. Quickly identifying and treating patients with out-of-hospital cardiac arrest related to acute cor- onary occlusion is associated with improved sur- vival and better functional recovery.S6-37 Coronary occlusion as a cause of cardiac arrest is not reli- ably predicted by clinical and electrocardiographic Recommendations for Management of Cardiac Arrest (Continued) COR LOE Recommendations CLINICAL STATEMENTS AND GUIDELINES and emergency coronary angiogra- phy should be considered (rather than later in the hospital stay or not at all) for unstable patients with a suspected cardiac etiology regardless of whether the patient is comatose or awake.S6-9,S6-39 In 1 observational study of patients resuscitated from SCA who did not have ST elevation and had angiography, one third were found to have a cul- prit lesion and coronary intervention appeared to be associated with a greater likelihood of favor- able neurologic outcome.S6-10 5. The initial management of any tachycardia should proceedaccordingtopublishedAHAadvancedcar- diovascular life support guidelines.S6-40 Immediate cardioversion should be performed for hemody- namic instability at presentation or if it develops subsequently. An ECG should be obtained for sta- ble rhythms. Wide-complex tachycardias, defined by a QRS duration 0.12 s,S6-37 can be due to VT, SVT with aberrancy, preexcited tachycardia, or a paced rhythm such as pacemaker-mediated tachycardia. An irregular wide-complex tachycar- dia may be AF with aberrancy, preexcited AF (ie, AF using an accessory pathway for anterograde conduction), atrial flutter, or VT.S6-37 A diagnosis should be established, and consultation with an arrhythmia expert considered.S6-37 6. 