The exception is in patients with signs of acute intoxication (eg, euphoria, tachycardia, and hypertension) and beta-blocker use unless patients are receiving coronary vasodilator therapy I C N/A (Continued) Amsterdam et al 2014 AHA/ACC NSTE-ACS Guideline e385 cardioversion for VF or pulseless sustained VT. Early admin- istration of beta blockers has been associated with reduction in The prophylactic use of lidocaine is not rec- ommended. Although VT/VF is associated with higher 90-day mortality risk, premature ventricular contractions not associ- ated with hemodynamic compromise and accelerated ventric- ular rhythms do not confer higher mortality risks and do not require specific therapy other than maintaining electrolyte bal- ance. NSTE-ACS non-sustained VT occurring >48 hours after admission indicates an increased risk of cardiac and sudden death, especially when associated with accompanying myo- Life-threatening ventricular arrhythmias that occur >48 hours after NSTE-ACS are usually associated with LV dysfunction and signify poor prognosis. RCTs in patients with ACS have shown consistent benefit of implant- able cardioverter-defibrillator therapy for survivors of VT or For other at-risk patients, especially those with significantly reduced LVEF, candidacy for primary prevention of sudden cardiac death with an implantable cardioverter-defi- brillator should be readdressed 40 days after discharge.583 A life vest may be considered in the interim. AF, atrial flutter, and other supraventricular arrhythmias may be triggered by excessive sympathetic stimulation, atrial stress due to volume overload, atrial infarction, pericarditis, electrolyte abnormalities, hypoxia, or pulmonary disease. AF is the most common of these arrhythmias and may develop in >20% of patients. 