It is reasonable to continue beta-blocker therapy in patients with normal LV function with NSTE- (Level of Evidence: C) Class III: Harm 1. Administration of intravenous beta blockers is poten- tially harmful in patients with NSTE-ACS who have risk factors for shock.244 (Level of Evidence: B) Beta blockers decrease heart rate, contractility, and BP, result- ing in decreased MVO2 . Beta blockers without increased sympathomimetic activity should be administered orally in the absence of contraindications. Although early administra- tion does not reduce short-term mortality,241,244 beta blockers decrease myocardial ischemia, reinfarction, and the frequency of complex ventricular dysrhythmias,240,245 and they increase long-term survival. Early beta blockade, particularly if given intravenously, can increase the likelihood of shock in patients with risk factors. Risk factors for shock include patients >70 years of age, heart rate >110 beats per minute, systolic BP <120 mmHg, and late presentation.244 In patients with LV dys- function (LVEF <0.40) with or without pulmonary congestion, beta blockers are strongly recommended before discharge. Beta blockers should be used prudently with ACE inhibitors or angiotensin-receptor blockers (ARBs) in patients with HF. Renin-angiotensin-aldosterone system blocking agents should be cautiously added in patients with decompensated HF.246 Beta blockers without intrinsic sympathomimetic activity should be used, especially beta-1 blockers such as sustained- release metoprolol succinate, bisoprolol, or carvedilol, a beta-1 and alpha-1 blocker. This is because of their mortality benefit in patients with HF and systolic dysfunction.246,247 In patients with chronic obstructive lung disease or a history of asthma, beta blockers are not contraindicated in the absence of active bronchospasm. Beta-1 selective beta blockers are preferred and should be initiated at a low dosage. See Online Data Supplement 11 for additional information on beta blockers, including risk factors for shock. 4.1.2.4. Calcium Channel Blockers: Recommendations Class I 1. 