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(Circulation. 1999;100:1016-1030.)
© 1999 American Heart Association, Inc.

ACC/AHA Practice Guidelines

1999 Update: ACC/AHA Guidelines for the Management of Patients With Acute Myocardial Infarction: Executive Summary and Recommendations

A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Acute Myocardial Infarction)

Committee Members; Thomas J. Ryan, MD, FACC, Chair; Elliott M. Antman, MD, FACC; Neil H. Brooks, MD, FAAFP; Robert M. Califf, MD, FACC; L. David Hillis, MD, FACC; Loren F. Hiratzka, MD, FACC; Elliot Rapaport, MD, FACC; Barbara Riegel, DNScFAAN; Richard O. Russell, MD, FACC; Earl E. Smith, III, MDFACEP; W. Douglas Weaver, MD, FACC; Task Force Members; Raymond J. Gibbons, MD, FACC, Chair; Joseph S. Alpert, MD, FACC; Kim A. Eagle, MD, FACC; Timothy J. Gardner, MD, FACC; Arthur Garson, Jr, MD, MPH, FACC; Gabriel Gregoratos, MD, FACC; Richard O. Russell, MD, FACC; Thomas J. Ryan, MD, FACC; Sidney C. Smith, Jr, MD, FACC

Key Words: AHA Scientific Statements • reperfusion • thrombolysis • myocardial infarction • angioplasty

	Introduction

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
The American College of Cardiology/American Heart Association (ACC/AHA) Guidelines for the Management of Patients With Acute Myocardial Infarction have been reviewed over the past 2.5 years since their initial publication in the Journal of the American College of Cardiology (1996;28:1328–1428) to ensure their continued relevancy. The guidelines have been updated to include the most significant advances that have occurred in the management of patients with acute myocardial infarction (AMI) during that time frame. This update was developed to keep the guidelines current without republishing the entire document. This effort represents a new procedure of the ACC/AHA Task Force on Practice Guidelines. These guidelines will be reviewed and updated as necessary until it is deemed appropriate to revise and republish the entire document.

The guidelines, incorporating the update, are available on the Web sites of both the American College of Cardiology (www.acc.org) and the American Heart Association (www.americanheart.org). In the Web site version, deleted text is indicated by strikeout, and new/revised text is presented as double-underlined type. Reprints of the original document with the revised sections appended are available from both organizations (see information below).

	Recommendations

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
The following is a listing of the recommendations made by the ACC/AHA Task Force on Practice Guidelines in the ACC/AHA Task Force Report "ACC/AHA Guidelines for the Management of Patients With Acute Myocardial Infarction." More detailed information regarding the evidence and the rationale for these recommendations can be found in the full text of the guidelines themselves, which appears in the November 1996 and September 1999 (update) issues of the Journal of the American College of Cardiology.

	Explanation of Classes

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
As in previous guidelines, the American College of Cardiology and the American Heart Association have used the following classification system in which indications for a diagnostic procedure, a particular therapy, or intervention are designated as:

Class I: Conditions for which there is evidence for and/or general agreement that a given procedure or treatment is beneficial, useful, and effective.

Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment.

Class IIa: Weight of evidence/opinion is in favor of usefulness/efficacy.

Class IIb: Usefulness/efficacy is less well established by evidence/opinion.

Class III: Conditions for which there is evidence and/or general agreement that a procedure/treatment is not useful/effective and in some cases may be harmful.

	Prehospital Issues

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Class I

1. Availability of 911 access. 2. Availability of an emergency medical services (EMS) system staffed by persons trained to treat cardiac arrest with defibrillation if indicated and to triage patients with ischemic-type chest discomfort.

Class IIa
1. Availability of a first-responder defibrillation program in a tiered response system. 2. Healthcare providers educate patients/families about signs and symptoms of AMI, accessing EMS, and medications.

Class IIb
1. Twelve-lead telemetry. 2. Prehospital thrombolysis in special circumstances (eg, transport time greater than 90 minutes).

	Initial Recognition and Management in the Emergency Department

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Class I
1. Emergency department (ED) AMI protocol that yields a targeted clinical examination and a 12-lead electrocardiogram (ECG) within 10 minutes and a door-to-needle time that is less than 30 minutes.

Routine Measures
1. Supplemental oxygen, intravenous access, and continuous electrocardiographic monitoring should be established in all patients with acute ischemic-type chest discomfort. 2. An ECG should be obtained and interpreted within 10 minutes of arrival in the ED in all patients with suspected acute ischemic-type chest discomfort.

	Oxygen

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Class I
1. Overt pulmonary congestion. 2. Arterial oxygen desaturation (SaO₂ less than 90%).

Class IIa
1. Routine administration to all patients with uncomplicated myocardial infarction (MI) during the first 2 to 3 hours.

Class IIb
1. Routine administration of supplemental oxygen to patients with uncomplicated MI beyond 3 to 6 hours.

	Intravenous Nitroglycerin

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Class I
1. For the first 24 to 48 hours in patients with AMI and congestive heart failure (CHF), large anterior infarction, persistent ischemia, or hypertension. 2. Continued use (beyond 48 hours) in patients with recurrent angina or persistent pulmonary congestion.

Class IIa
None.

Class IIb
1. For the first 24 to 48 hours in all patients with AMI who do not have hypotension, bradycardia, or tachycardia. 2. Continued use (beyond 48 hours)*¹ in patients with a large or complicated infarction.

Class III
1. Patients with systolic blood pressure less than 90 mm Hg or severe bradycardia (less than 50 bpm).

	Aspirin

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Class I
1. A dose of 160 to 325 mg should be given on day 1 of AMI and continued indefinitely on a daily basis.

View this table: [in this window] [in a new window]   Table 1.

	Atropine

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Class I
1. Sinus bradycardia with evidence of low cardiac output and peripheral hypoperfusion or frequent premature ventricular complexes at onset of symptoms of AMI. 2. Acute inferior infarction with type I second- or third-degree atrioventricular (AV) block associated with symptoms of hypotension, ischemic discomfort, or ventricular arrhythmias. 3. Sustained bradycardia and hypotension after administration of nitroglycerin. 4. For nausea and vomiting associated with administration of morphine. 5. Ventricular asystole.

Class IIa
1. Symptomatic patients with inferior infarction and type I second- or third-degree heart block at the level of the AV node (ie, with narrow QRS complex or with known existing bundle-branch block [BBB]).

Class IIb
1. Administration concomitant with (before or after) administration of morphine in the presence of sinus bradycardia. 2. Asymptomatic patients with inferior infarction and type I second-degree heart block or third-degree heart block at the level of the AV node. 3. Second- or third-degree AV block of uncertain mechanism when pacing is not available.

Class III
1. Sinus bradycardia greater than 40 bpm without signs or symptoms of hypoperfusion or frequent premature ventricular contractions. 2. Type II AV block and third-degree AV block and third-degree AV block with new wide QRS complex presumed due to AMI.

	Thrombolysis

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Class I
1. ST elevation (greater than 0.1 mV, two or more contiguous leads),² time to therapy 12 hours or less,³ age less than 75 years. 2. BBB (obscuring ST-segment analysis) and history suggesting AMI.

Class IIa
1. ST elevation,*³ age 75 years or older.

Class IIb
1. ST elevation,² time to therapy greater than 12 to 24 hours.*³ 2. Blood pressure on presentation greater than 180 mm Hg systolic and/or greater than 110 mm Hg diastolic associated with high-risk MI.

Class III
1. ST elevation,² time to therapy greater than 24 hours,*³ ischemic pain resolved. 2. ST-segment depression only.

View this table: [in this window] [in a new window]   Table 2.

Primary Percutaneous Transluminal Coronary Angioplasty (PTCA)

	Early Coronary Angiography in the ST-Segment Elevation or BBB Cohort Not Undergoing Primary PTCA

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Class I
None.

Class IIa
1. Patients with cardiogenic shock or persistent hemodynamic instability.

Class IIb
1. Patients with evolving large or anterior infarcts treated with thrombolytic agents in whom it is believed that the artery is not patent and adjuvant PTCA is planned.

Class III
1. Routine use of angiography and subsequent PTCA within 24 hours of administration of thrombolytic agents.

	Emergency or Urgent Coronary Artery Bypass Graft (CABG) Surgery

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Class I
1. Failed angioplasty with persistent pain or hemodynamic instability in patients with coronary anatomy suitable for surgery. 2. AMI with persistent or recurrent ischemia refractory to medical therapy in patients with coronary anatomy suitable for surgery who are not candidates for catheter intervention. 3. At the time of surgical repair of postinfarction ventricular septal defect (VSD) or mitral valve insufficiency.

Class IIa
1. Cardiogenic shock with coronary anatomy suitable for surgery.

Class IIb
1. Failed PTCA and small area of myocardium at risk; hemodynamically stable.

Class III
1. When the expected surgical mortality rate equals or exceeds the mortality rate associated with appropriate medical therapy.

View this table: [in this window] [in a new window]   Table 3.

Early Coronary Angiography and/or Interventional Therapy in Non–ST-Segment Elevation Cohort

Glycoprotein IIb/IIIa Inhibitors

View this table: [in this window] [in a new window]   Table 4.

	Hospital Management

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Early, General Measures
Class I

1. Selection of ECG monitoring based on infarct location and rhythm. 2. Bed rest with bedside commode privileges for initial 12 hours in hemodynamically stable patients free of ischemic-type chest discomfort. 3. Avoidance of Valsalva. 4. Careful attention to maximum pain relief.

Class IIb
1. Routine use of anxiolytics.

Class III
1. Prolonged bed rest (more than 12 to 24 hours) in stable patients without complications.

	Identification and Treatment of the Patient at High Risk

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Management of Recurrent Chest Discomfort
Class I

1. Aspirin for pericarditis. 2. ß-Adrenoceptor blockers intravenously, then orally for ischemic-type chest discomfort. 3. (Re)administration of thrombolytic therapy (alteplase) for patients with recurrent ST elevation. 4. Coronary arteriography for ischemic-type chest discomfort recurring after hours to days of initial therapy and associated with objective evidence of ischemia in patients who are candidates for revascularization.

Class IIa
1. Nitroglycerin intravenously for 24 hours, then topically or orally for ischemic-type chest discomfort.

Class IIb
1. Corticosteroids for pericarditis. 2. Indomethacin for pericarditis.

	Hemodynamic Monitoring

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Balloon Flotation Right-Heart Catheter Monitoring
Class I

1. Severe or progressive CHF or pulmonary edema. 2. Cardiogenic shock or progressive hypotension. 3. Suspected mechanical complications of acute infarction, ie, VSD, papillary muscle rupture, or pericardial tamponade.

Class IIa
1. Hypotension that does not respond promptly to fluid administration in a patient without pulmonary congestion.

Class III
1. Patients with acute infarction without evidence of cardiac or pulmonary complications.

	Intra-arterial Pressure Monitoring

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Class I
1. Patients with severe hypotension (systolic arterial pressure less than 80 mm Hg) and/or cardiogenic shock. 2. Patients receiving vasopressor agents.

Class IIa
1. Patients receiving intravenous sodium nitroprusside or other potent vasodilators.

Class IIb
1. Hemodynamically stable patients receiving intravenous nitroglycerin for myocardial ischemia. 2. Patients receiving intravenous inotropic agents.

Class III
1. Patients with acute infarction who are hemodynamically stable.

	Intra-aortic Balloon Counterpulsation

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Class I
1. Cardiogenic shock not quickly reversed with pharmacological therapy as a stabilizing measure for angiography and prompt revascularization. 2. Acute mitral regurgitation or VSD complicating MI as a stabilizing therapy for angiography and repair/revascularization. 3. Recurrent intractable ventricular arrhythmias with hemodynamic instability. 4. Refractory post-MI angina as a bridge to angiography and revascularization.

Class IIa
1. Signs of hemodynamic instability, poor LV function, or persistent ischemia in patients with large areas of myocardium at risk.

Class IIb
1. In patients with successful PTCA after failed thrombolysis or those with three-vessel coronary disease to prevent reocclusion. 2. In patients known to have large areas of myocardium at risk with or without active ischemia.

Rhythm Disturbances
Atrial Fibrillation
Class I

1. Electrical cardioversion for patients with severe hemodynamic compromise or intractable ischemia. 2. Rapid digitalization to slow a rapid ventricular response and improve LV function. 3. Intravenous ß-adrenoceptor blockers to slow a rapid ventricular response in patients without clinical LV dysfunction, bronchospastic disease, or AV block. 4. Heparin should be given.

Class IIa
1. Either diltiazem or verapamil intravenously to slow a rapid ventricular response if ß-adrenoceptor blocking agents are contraindicated or ineffective.

	Ventricular Tachycardia/Ventricular Fibrillation

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Class I
1. Ventricular fibrillation (VF) should be treated with an unsynchronized electric shock with an initial energy of 200 J; if unsuccessful, a second shock of 200 to 300 J should be given, and, if necessary, a third shock of 360 J. 2. Sustained (more than 30 seconds or causing hemodynamic collapse) polymorphic ventricular tachycardia (VT) should be treated with an unsynchronized electric shock using an initial energy of 200 J; if unsuccessful, a second shock of 200 to 300 J should be given, and, if necessary, a third shock of 360 J. 3. Episodes of sustained monomorphic VT associated with angina, pulmonary edema, or hypotension (blood pressure less than 90 mm Hg) should be treated with a synchronized electric shock of 100 J initial energy. Increasing energies may be used if not initially successful. 4. Sustained monomorphic VT not associated with angina, pulmonary edema, or hypotension (blood pressure less than 90 mm Hg) should be treated with one of the following regimens: a. Lidocaine: bolus 1.0 to 1.5 mg/kg. Supplemental boluses of 0.5 to 0.75 mg/kg every 5 to 10 minutes to a maximum of 3 mg/kg total loading dose may be given as needed. Loading is followed by infusion of 2 to 4 mg/min (30 to 50 µg/kg per minute). b. Procainamide: 20 to 30 mg/min loading infusion, up to 12 to 17 mg/kg. This may be followed by an infusion of 1 to 4 mg/min. c. Amiodarone: 150 mg infused over 10 minutes followed by a constant infusion of 1.0 mg/min for 6 hours and then a maintenance infusion of 0.5 mg/min. d. Synchronized electrical cardioversion starting at 50 J (brief anesthesia is necessary).

Class IIa
1. Infusions of antiarrhythmic drugs may be used after an episode of VT/VF but should be discontinued after 6 to 24 hours and the need for further arrhythmia management assessed. 2. Electrolyte and acid-base disturbances should be corrected to prevent recurrent episodes of VF when an initial episode of VF has been treated.

Class IIb
1. Drug-refractory polymorphic VT should be managed by aggressive attempts to reduce myocardial ischemia, including therapies such as ß-adrenoceptor blockade, intra-aortic balloon pumping, and emergency PTCA/CABG surgery. Amiodarone, 150 mg infused over 10 minutes followed by a constant infusion of 1.0 mg/min for up to 6 hours and then a maintenance infusion of 0.5 mg/min may also be helpful.

Class III
1. Treatment of isolated ventricular premature beats, couplets, runs of accelerated idioventricular rhythm, and nonsustained VT. 2. Prophylactic administration of antiarrhythmic therapy when using thrombolytic agents.

	Bradyarrhythmias and Heart Block

Top Introduction Recommendations Explanation of Classes Prehospital Issues Initial Recognition and... Oxygen Intravenous Nitroglycerin Aspirin Atropine Thrombolysis Early Coronary Angiography in... Emergency or Urgent Coronary... Hospital Management Identification and Treatment of... Hemodynamic Monitoring Intra-arterial Pressure... Intra-aortic Balloon... Ventricular... Bradyarrhythmias and Heart Block Other Surgical Interventions Rationale and Approach to... Calcium Channel Blockers Magnesium Preparation for Discharge From... Assessment of Ventricular...

 
Atropine
Class I

1. Symptomatic sinus bradycardia (generally, heart rate less than 50 bpm associated with hypotension, ischemia, or escape ventricular arrhythmia). 2. Ventricular asystole. 3. Symptomatic AV block occurring at the AV nodal level (second-degree type I or third-degree with a narrow-complex escape rhythm).

Class IIa
None.

Class III
1. AV block occurring at an infranodal level (usually associated with anterior MI with a wide-complex escape rhythm). 2. Asymptomatic sinus bradycardia.

Temporary Pacing
Placement of Transcutaneous Patches*⁴ and Active (Demand) Transcutaneous Pacing⁵
Class I

1. Sinus bradycardia (rate less than 50 bpm) with symptoms of hypotension (systolic blood pressure less than 80 mm Hg) unresponsive to drug therapy.⁵ 2. Mobitz type II second-degree AV block.⁵ 3. Third-degree heart block.⁵ 4. Bilateral BBB (alternating BBB, or right BBB [RBBB] and alternating left anterior fascicular block [LAFB], left posterior fascicular block [LPFB]) (irrespective of time of onset).*⁴ 5. Newly acquired or age-indeterminate LBBB, LBBB and LAFBa, RBBB, and LPFBa.*⁴ 6. RBBB or LBBB and first-degree AV block.*⁴

Class IIa
1. Stable bradycardia (systolic blood pressure greater than 90 mm Hg, no hemodynamic compromise, or compromise responsive to initial drug therapy).*⁶ 2. Newly acquired or age-indeterminate RBBB.*⁶

Class IIb
1. Newly acquired or age-indeterminate first-degree AV block.*⁶

Class III
1. Uncomplicated AMI without evidence of conduction system disease.

Temporary Transvenous Pacing⁷
Class I
1. Asystole. 2. Symptomatic bradycardia (includes sinus bradycardia with hypotension and type I second-degree AV block with hypotension not responsive to atropine). 3. Bilateral BBB (alternating BBB or RBBB with alternating LAFB/LPFB) (any age). 4. New or indeterminate-age bifascicular block (RBBB with LAFB or LPFB, or LBBB) with first-degree AV block. 5. Mobitz type II second-degree AV block.

Class IIa
1. RBBB and LAFB or LPFB (new or indeterminate). 2. RBBB with first-degree AV block. 3. LBBB, new or indeterminate. 4. Incessant VT, for atrial or ventricular overdrive pacing. 5. Recurrent sinus pauses (greater than 3 seconds) not responsive to atropine.

Class IIb
1. Bifascicular block of indeterminate age. 2. New or age-indeterminate isolated RBBB.

Class III
1. First-degree heart block. 2. Type I second-degree AV block with normal hemodynamics. 3. Accelerated idioventricula