In a prespecified secondary analysis, ranolazine was associated with a significant reduction in VT events treated with anti-tachycardia 5.1.2. Beta Blockers Because of their excellent safety profile and effec- tiveness in treating VA and reducing the risk of SCD, beta blockers are often first-line antiarrhythmic Their antiarrhythmic efficacy is related to the effects of adrenergic-receptor blockade on sympathetically mediated triggering mechanisms, slowing of the sinus rate, and possibly inhibition of ex- cess calcium release by the ryanodine receptor.S5.1.5.2-12 Beta blockers reduce all-cause mortality and SCD in patients with HF with reduced EF (HFrEF).S5.1.5.2-13 S5.1.5.2-15 Although beta blockers have long been proven to re- duce mortality after MI,S5.1.5.2-16 registry data confirm that early beta blocker use in patients with MI and risk factors for shock (>70 years of age, symptoms <12 hours [ST-elevation MI patients], systolic blood pres- sure <120 mm Hg, and heart rate >110 beat/min on presentation) is associated with an increased risk of shock or death.S5.1.5.2-17 In the setting of polymorphic VT after MI, beta blockers reduce mortality.S5.1.5.2-18 Beta blockers suppress VA in some patients with structurally When used in combination with membrane-stabilizing antiarrhythmic medications, beta blockers can enhance antiarrhythmic efficacy.S5.1.5.2-20 Beta blockers (eg, nadolol, propranolol) are also first- line therapy for some cardiac channelopathies (eg, long QT syndrome, catecholaminergic polymorphic ventricu- lar tachycardia). 5.1.3. Amiodarone and Sotalol Amiodarone possesses a wide spectrum of actions that include blockade of beta receptors and sodium, calci- um and potassium currents (ie, a multichannel blocker). Its overall long-term effect on survival is controversial, with most studies showing no clear advantage over placebo. 