Circulation Atmegiso tmO Learn and live JOURNAL OF THE AMERICAN HEART ASSOCIATION Part 7.3: Management of Symptomatic Bradycardia and tachycardia Circulation 2005; 112: 67-77; originally published online Nov 28, 2005 DOI: 10.1161/CIRCULATIONAHA. 105.166558 Circulation is published by the American Heart Association. 7272 Greenville Avenue, Dallas, Tx 72514 Copyright o 2005 American Heart Association. All rights reserved. Print ISSN: 0009-7322. Online ISSN:15244539 The online version of this article, along with updated information and services, is located on the World wide web at http://circ.ahajournals.org/cgi/content/full/112/24suppl/iv-67 Subscriptions: Information about subscribing to Circulation is online at http://circ.ahajournals.org/subsriptions/ Permissions: Permissions Rights Desk, Lippincott Williams Wilkins, 351 West Cam Street. Baltimore MD 21202-2436 Phone 410-5280-4050. Fax: 410-528-8550 En journalpermissions@lww.com Reprints: Information about reprints can be found online at http://www.Iww.com/static/html/reprints.html Downloaded from circ. ahajournals. org by on February 21, 2006
ISSN: 1524-4539 Copyright © 2005 American Heart Association. All rights reserved. Print ISSN: 0009-7322. Online 72514 Circulation is published by the American Heart Association. 7272 Greenville Avenue, Dallas, TX DOI: 10.1161/CIRCULATIONAHA.105.166558 Circulation 2005;112;67-77; originally published online Nov 28, 2005; Part 7.3: Management of Symptomatic Bradycardia and Tachycardia http://circ.ahajournals.org/cgi/content/full/112/24_suppl/IV-67 located on the World Wide Web at: The online version of this article, along with updated information and services, is http://www.lww.com/static/html/reprints.html Reprints: Information about reprints can be found online at journalpermissions@lww.com Street, Baltimore, MD 21202-2436. Phone 410-5280-4050. Fax: 410-528-8550. Email: Permissions: Permissions & Rights Desk, Lippincott Williams & Wilkins, 351 West Camden http://circ.ahajournals.org/subsriptions/ Subscriptions: Information about subscribing to Circulation is online at Downloaded from circ.ahajournals.org by on February 21, 2006
Part 7.3: Management of Symptomatic Bradycardia and tachycardia Cac a aohithrnnas she u (do ommon cause of sudden death A comprehensive presentation of the evaluation and man- be established on as agement of bradyarrhythmias and tachyarrhythmias is beyond possible for all patients who collapse suddenly or have the scope of these guidelines. For further information see the symptoms of coronary ischemia or infarction. To avoid delay, apply adhesive electrodes with a conventional or automated external defibrillator(AED)or use the"quick-look"paddles American College of Cardiology/American Heart Associ- feature on conventional defibrillators. For patients with acute ation/European Society of Cardiology Guidelines for the coronary ischemia, the greatest risk for serious arrhythmias Management of Patients With Supraventricular Arrhyth- occurs during the first 4 hours after the onset of symptoms mias,availableatthefollowingsiteswww.acc.org, (see Part 8: " Stabilization of the Patient With Acute Coronary www.americanheart.organdwww.escardio.org ACLS: Principles and Practice, Chapters 12 through 16.4 Principles of Arrhythmia Recognition There are 3 major sections in Part 7.3. The first 2 sections and management Bradycardia"and"Tachycardia, "begin with evaluation and The ECG and rhythm information should be interp treatment and provide an overview of the information sum- within the context of total patient assessment. Errors marized in the aCls bradycardia and tachycardia algorithms. iagnosis and treatment are likely to occur if ACLS providers To simplify these algorithms, we have included some recom base treatment decisions solely on rhythm interpretation and mended drugs but not all possible useful drugs. The overview presents information about the drugs cited in the algorithms. neglect clinical evaluation. Providers must evaluate the pa- The third section, ""Antiarrhythmic Drugs, provides more tient's symptoms and clinical signs, including ventilation, oxygenation, heart rate, blood pressure, and level of con detailed information about a wider selection of drug sciousness, and look for signs of inadequate organ perfusion. therapies These guidelines emphasize the importance of clinical eval- uation and highlight principles of therapy with algorithms Bradycardia that have been refined and streamlined since the 2000 edition See the Bradycardia Algorithm, Figure 1. Box numbers in the of the guidelines. 2 The principles of arrhythmia recognition text refer to the numbered boxes in the algorithm and management in adults are as follow Evaluation If brady altered mental status, ongoing severe ischemic chest pain, Bradycardia is generally defined as a heart rate of <60 congestive heart failure, hypotension, or other signs of per minute( Box 1). A slow heart rate may be physiologically normal for sol shock) that persist despite adequate airway and breathing and heart rates >60 beats prepare to provide pacing. For symptomatic high-degree minute may be inadequate for others. This bradycardia (second-degree or third-degree) atrioventricular (AV algorithm focuses on management of clinically significant block, provide transcutaneous pacing without delay. bradycardia (ie, bradycardia that is inadequate for clinical If the tachycardic patient is unstable with severe signs and condition) symptoms related to tachycardia, prepare for immediate Initial treatment of any patient with bradycardia should cardioversion focus on support of airway and breathing(Box 2). Provide If the patient with tachycardia is stable, determine if the supplementary oxygen, place the patient on a monitor, eval patient has a narrow-complex or wide-complex tachycardia uate blood pressure and oxyhemoglobin saturation, and and then tailor therapy accordingly tablish intravenous (IV) access. Obtain an ECG to better You must understand the initial diagnostic electrical and define the rhythm. While initiating treatment, evaluate the drug treatment options for rhythms that are unstable or clinical status of the patient and identify potential reversible immediately life-threatenin causes Know when to call for expert consultation regarding The provider must identify signs and symptoms of poor complicated rhythm interpretation, drugs, or management perfusion and determine if those signs are likely to be caused by the bradycardia(Box 3). Signs and symptoms cardia may be mild, and asymptomatic patients do not require ( Circulation. 2005: 112: IV-67-IV-77. reatment. They should be monitored for signs of deteriora- o 2005 American Heart Association tion(Box 4A) Provide immediate therapy for patients with This special supplement to Circulation is freely available http://www.circulationaha.org hypotension, acute altered mental status, chest pain, conges- ive heart failure, seizures, syncope, or other signs of shock DOI: 10.1161/CIRCULATIONAHA 105. 166558 related to the bradycardia(Box 4)
Part 7.3: Management of Symptomatic Bradycardia and Tachycardia Cardiac arrhythmias are a common cause of sudden death. ECG monitoring should be established as soon as possible for all patients who collapse suddenly or have symptoms of coronary ischemia or infarction. To avoid delay, apply adhesive electrodes with a conventional or automated external defibrillator (AED) or use the “quick-look” paddles feature on conventional defibrillators. For patients with acute coronary ischemia, the greatest risk for serious arrhythmias occurs during the first 4 hours after the onset of symptoms (see Part 8: “Stabilization of the Patient With Acute Coronary Syndromes”).1 Principles of Arrhythmia Recognition and Management The ECG and rhythm information should be interpreted within the context of total patient assessment. Errors in diagnosis and treatment are likely to occur if ACLS providers base treatment decisions solely on rhythm interpretation and neglect clinical evaluation. Providers must evaluate the patient’s symptoms and clinical signs, including ventilation, oxygenation, heart rate, blood pressure, and level of consciousness, and look for signs of inadequate organ perfusion. These guidelines emphasize the importance of clinical evaluation and highlight principles of therapy with algorithms that have been refined and streamlined since the 2000 edition of the guidelines.2 The principles of arrhythmia recognition and management in adults are as follows: ● If bradycardia produces signs and symptoms (eg, acute altered mental status, ongoing severe ischemic chest pain, congestive heart failure, hypotension, or other signs of shock) that persist despite adequate airway and breathing, prepare to provide pacing. For symptomatic high-degree (second-degree or third-degree) atrioventricular (AV) block, provide transcutaneous pacing without delay. ● If the tachycardic patient is unstable with severe signs and symptoms related to tachycardia, prepare for immediate cardioversion. ● If the patient with tachycardia is stable, determine if the patient has a narrow-complex or wide-complex tachycardia and then tailor therapy accordingly. ● You must understand the initial diagnostic electrical and drug treatment options for rhythms that are unstable or immediately life-threatening. ● Know when to call for expert consultation regarding complicated rhythm interpretation, drugs, or management decisions. A comprehensive presentation of the evaluation and management of bradyarrhythmias and tachyarrhythmias is beyond the scope of these guidelines. For further information see the following sources: ● American College of Cardiology/American Heart Association/European Society of Cardiology Guidelines for the Management of Patients With Supraventricular Arrhythmias,3 available at the following sites: www.acc.org, www.americanheart.org, and www.escardio.org. ● ACLS: Principles and Practice, Chapters 12 through 16.4 There are 3 major sections in Part 7.3. The first 2 sections, “Bradycardia” and “Tachycardia,” begin with evaluation and treatment and provide an overview of the information summarized in the ACLS bradycardia and tachycardia algorithms. To simplify these algorithms, we have included some recommended drugs but not all possible useful drugs. The overview presents information about the drugs cited in the algorithms. The third section, “Antiarrhythmic Drugs,” provides more detailed information about a wider selection of drug therapies. Bradycardia See the Bradycardia Algorithm, Figure 1. Box numbers in the text refer to the numbered boxes in the algorithm. Evaluation Bradycardia is generally defined as a heart rate of 60 beats per minute (Box 1). A slow heart rate may be physiologically normal for some patients, and heart rates 60 beats per minute may be inadequate for others. This bradycardia algorithm focuses on management of clinically significant bradycardia (ie, bradycardia that is inadequate for clinical condition). Initial treatment of any patient with bradycardia should focus on support of airway and breathing (Box 2). Provide supplementary oxygen, place the patient on a monitor, evaluate blood pressure and oxyhemoglobin saturation, and establish intravenous (IV) access. Obtain an ECG to better define the rhythm. While initiating treatment, evaluate the clinical status of the patient and identify potential reversible causes. The provider must identify signs and symptoms of poor perfusion and determine if those signs are likely to be caused by the bradycardia (Box 3). Signs and symptoms of bradycardia may be mild, and asymptomatic patients do not require treatment. They should be monitored for signs of deterioration (Box 4A). Provide immediate therapy for patients with hypotension, acute altered mental status, chest pain, congestive heart failure, seizures, syncope, or other signs of shock related to the bradycardia (Box 4). (Circulation. 2005;112:IV-67-IV-77.) © 2005 American Heart Association. This special supplement to Circulation is freely available at http://www.circulationaha.org DOI: 10.1161/CIRCULATIONAHA.105.166558 IV-67
IV-68 Circulation December 13, 2005 BRADYCARDIA Heart rate <60 bpm and inadequate for clinical condition Maintain patent airway; assist breathing as needed Give c Monitor ECG (identify rhythm), blood pressure, oximetry Signs or symptoms of poor perfusion caused by the bradycardia? (eg, acute altered mental status, ongoing chest pain, hypotension or other signs of sho Perfusion Pertusio Observe/Monitor Prepare for transcutaneous pacing use without delay for high-degree block (type ll second-degree block or third-degree AV block Consider atropine 0.5 mg IV while awaiting pacer, May repeat to a total dose of 3 mg. If ineffective, Consider epinephrine (2 to 10 ug/min) or dopamine (2 to 10 ug/kg per If pulseless arest develops, go to Pulseless Arrest Algorithm infusion while awaiting pacer or ir ute Search for and treat possible contributing factors: pacing ineffective Hypovolemia Tamponade, cardiac Hydrogen ion (acidosis)- Tension pneumothorax Hypo-/hyperkalemia- Thrombosis(coronary or pulmonary Prepare for transvenous pacing Trauma (hypovolemia, increased ICP) Treat contributing causes Consider expert consultation Fig aV blocks are classified as first, second, and third degre They may be caused by medications or electrolyte distur- In the absence of reversible causes, atropine remains the bances,as well as structural problems resulting from acute first-line drug for acute symptomatic bradycardia(Class lla) myocardial infarction and myocarditis. A first-degree AV In I randomized clinical trial in adults (Loe 2)5 and addi- block is defined by a prolonged PR interval(>0.20 second tional lower-level studies(LOE 4), 6.7 IV atropine improved and is usually benign. Second-degree AV block is divided heart rate and signs and symptoms associated with bradycar into Mobitz types I and Il. In Mobitz type I block, the block dia. An initial dose of 0.5 mg, repeated as needed to a total of is at the AV node; the block is often transient and may be 1.5 mg, was effective in both in-hospital and out-of-hospital asymptomatic. In Mobitz type II block, the block is most dycardia 5-7 Transcutaneous often below the Av node at the bundle of His or at the bundle pacing is usually indicated if the patient fails to respond to atropine, although second-line drug therapy with drugs such branches: the block is often symptomatic, with the potential atropine, although to progress to complete(third-degree) Av block. Third- as dopamine or epinephrine may be successful(see below) degree heart block may occur at the Av node, bundle of Hi Use transcutaneous pacing without delay for symptomatic high-degree(second-degree or third-deg gree)block. Atropine bundle branches. When third-degree AV block is present, sulfate reverses cholinergic-mediated decreases in heart rate no impulses pass between the atria and ventricles. Third- and should be considered a temporizing measure while degree heart block can be permanent or transient, depending awaiting a transcutaneous pacemaker for patients with symp on the underlying cause tomatic high-degree AV block. Atropine is useful for treating symptomatic sinus bradycardia and may be beneficial for any Therapy(Box 4) type of AV block at the nodal level. 7 Be prepared to initiate transcutaneous pacing quickly in The recommended atropine dose for bradycardia is 0.5 m patients who do not respond to atropine(or second-line drugs IV every 3 to 5 minutes to a maximum total dose of 3 mg if these do not delay definitive management). Pacing is also Doses of atropine sulfate of <0.5 mg may paradoxically recommended for severely symptomatic patients, especially result in further slowing of the heart rate. 8 Atropine admin- when the block is at or below the His-Purkinje level (ie, type for patients with poor perfusion istration should not delay implementation of external pacing II second-degree or third-degree Av block)
AV blocks are classified as first, second, and third degree. They may be caused by medications or electrolyte disturbances, as well as structural problems resulting from acute myocardial infarction and myocarditis. A first-degree AV block is defined by a prolonged PR interval (0.20 second) and is usually benign. Second-degree AV block is divided into Mobitz types I and II. In Mobitz type I block, the block is at the AV node; the block is often transient and may be asymptomatic. In Mobitz type II block, the block is most often below the AV node at the bundle of His or at the bundle branches; the block is often symptomatic, with the potential to progress to complete (third-degree) AV block. Thirddegree heart block may occur at the AV node, bundle of His, or bundle branches. When third-degree AV block is present, no impulses pass between the atria and ventricles. Thirddegree heart block can be permanent or transient, depending on the underlying cause. Therapy (Box 4) Be prepared to initiate transcutaneous pacing quickly in patients who do not respond to atropine (or second-line drugs if these do not delay definitive management). Pacing is also recommended for severely symptomatic patients, especially when the block is at or below the His-Purkinje level (ie, type II second-degree or third-degree AV block). Atropine In the absence of reversible causes, atropine remains the first-line drug for acute symptomatic bradycardia (Class IIa). In 1 randomized clinical trial in adults (LOE 2)5 and additional lower-level studies (LOE 4),6,7 IV atropine improved heart rate and signs and symptoms associated with bradycardia. An initial dose of 0.5 mg, repeated as needed to a total of 1.5 mg, was effective in both in-hospital and out-of-hospital treatment of symptomatic bradycardia.5–7 Transcutaneous pacing is usually indicated if the patient fails to respond to atropine, although second-line drug therapy with drugs such as dopamine or epinephrine may be successful (see below). Use transcutaneous pacing without delay for symptomatic high-degree (second-degree or third-degree) block. Atropine sulfate reverses cholinergic-mediated decreases in heart rate and should be considered a temporizing measure while awaiting a transcutaneous pacemaker for patients with symptomatic high-degree AV block. Atropine is useful for treating symptomatic sinus bradycardia and may be beneficial for any type of AV block at the nodal level.7 The recommended atropine dose for bradycardia is 0.5 mg IV every 3 to 5 minutes to a maximum total dose of 3 mg. Doses of atropine sulfate of 0.5 mg may paradoxically result in further slowing of the heart rate.8 Atropine administration should not delay implementation of external pacing for patients with poor perfusion. Figure 1. Bradycardia Algorithm. IV-68 Circulation December 13, 2005
Part 7.3: Management of Symptomatic Bradycardia and Tachycardia Iv-69 Use atropine cautiously in the presence of acute coronary Glucagon ischemia or myocardial infarction; increased heart rate may One case series(Loe 5) o documented improvement in heart worsen ischemia or increase the zone of infarction rate,symptoms, and signs associated with bradycardia when Atropine may be used with caution and appropriate mon- IV glucagon (3 mg initially, followed by infusion at 3 mg/h if itoring following cardiac transplantation. It will likely be necessary) was given to in-hospital patients with drug- ineffective because the transplanted heart lacks vagal inner- induced(eg, B-blocker or calcium channel blocker overdose) ation. One small uncontrolled study(LoE 5) documented symptomatic bradycardia not responding to atropine paradoxical slowing of the heart rate and high-degree AV block when atropine was administered to patients after Tachycardia cardiac transplantation This section summarizes the management of a wide variety of Avoid relying on atropine in type I second-degree or tachyarrhythmias. Following the overview of tachyarrhythmias third-degree AV block or in patients with third-degree AV and summary of the initial evaluation and treatment of block with a new wide-QRS complex. These patients require tachycardia, common antiarrhythmic drugs used in the treatment P Classification of Tachyarrhythmias Transcutaneous pacing is a Class I intervention for symptom- The tachycardias can be classified in several ways based on atic bradycardias. It should be started immediately for pa- the appearance of the QRS complex. Professionals at the tients who are unstable, particularly those with high-degree ACLS level should be able to recognize and differentiate (Mobitz type II second-degree or third-degree) block. Some between sinus tachycardia, narrow-complex supraventricular limitations apply. Transcutaneous pacing can be painful and tachycardia (SVT), and wide-complex tachycardia. Because may fail to produce effective mechanical capture. If cardio- ACLS providers may be unable to distinguish between vascular symptoms are not caused by the bradycardia, the supraventricular and ventricular rhythms, they should be patient may not improve despite effective pacing aware that most wide-complex(broad-complex) tachycardias Transcutaneous pacing is noninvasive and can be per- are ventricular in origin formed by ecc providers at the bedside. Initiate transcut neous pacing immediately if there is no response to atropine Narrow-QRS-complex (SVT) tachycardias(QRS <0.12 if atropine is unlikely to be effective, or if the patient is second)in order of frequency everely symptomatic. Verify mechanical capture and re- Sinus tachycardia assess the patients condition. Use analgesia and sedation for Atrial fibrillation pain control, and try to identify the cause of the Atrial flutter AV nodal reentry If transcutaneous pacing is ineffective (eg, inconsistent Accessory pathway-mediated tachycardia capture), prepare for transvenous pacing and consider obtain- Atrial tachycardia(ectopic and reentrant) Multifocal atrial tachycardia(MAT) Junctional tachycardia Alternative Drugs to Consider These drugs are not first-line agents for treatment of symp- Wide-QRS-complex tachycardias(QRs 20.12 second) tomatic bradycardia. They may be considered when the Ventricular tachycardia (VT) bradycardia is unresponsive to atropine and as temporizing SVt with abe measures while awaiting the availability of a pacemaker. To Pre-excited tachycardias (advanced recognition sIn nplify the algorithm, we have listed epinephrine and rhythms using an accessory pathway) dopamine as alternative drugs to consider(Class IIb); they are Irregular narrow-complex tachycardias are probably atrial widely available and familiar to ACLS clinicians. In this fibrillation or possibly atrial flutter or MAT. The manage section we also summarize evidence in support of other drugs ment of atrial fibrillation and flutter is discussed in the section Epinephrine infusion may be used for patients with symp- Initial Evaluation and Treatment of Tachyarrhythmias tomatic bradycardia or hypotension after atropine or pacing The evaluation and management of tachyarrhythmias is fails( Class Ib). Begin the infusion at 2 to 10 ug/min and depicted in the ACLS Tachycardia Algorithm(Figure 2).Box titrate to patient response. Assess intravascular volume and numbers in the text refer to numbered boxes in this algorithm. pport as needed Note that the " screened boxes (boxes with text that is noticeably lighter, ie, Boxes 9, 10, 11, 13, and 14)indicate Dopamine therapies that are intended for in-hospital use or with expert Dopamine hydrochloride has both a- and B-adrenergic ac- consultation available. tions. Dopamine infusion(at rates of 2 to 10 ug/kg per This algorithm summarizes the management of the tachy minute)can be added to epinephrine or administered alone. adic patient with pulses(Box 1). If pulseless arrest develops Titrate the dose to patient response. Assess intravascular at any time, see the ACls Pulseless Arrest Algorithm in Part volume and support as needed 7.2: Management of Cardiac Arrest
Use atropine cautiously in the presence of acute coronary ischemia or myocardial infarction; increased heart rate may worsen ischemia or increase the zone of infarction. Atropine may be used with caution and appropriate monitoring following cardiac transplantation. It will likely be ineffective because the transplanted heart lacks vagal innervation. One small uncontrolled study (LOE 5)9 documented paradoxical slowing of the heart rate and high-degree AV block when atropine was administered to patients after cardiac transplantation. Avoid relying on atropine in type II second-degree or third-degree AV block or in patients with third-degree AV block with a new wide-QRS complex. These patients require immediate pacing. Pacing Transcutaneous pacing is a Class I intervention for symptomatic bradycardias. It should be started immediately for patients who are unstable, particularly those with high-degree (Mobitz type II second-degree or third-degree) block. Some limitations apply. Transcutaneous pacing can be painful and may fail to produce effective mechanical capture. If cardiovascular symptoms are not caused by the bradycardia, the patient may not improve despite effective pacing. Transcutaneous pacing is noninvasive and can be performed by ECC providers at the bedside. Initiate transcutaneous pacing immediately if there is no response to atropine, if atropine is unlikely to be effective, or if the patient is severely symptomatic. Verify mechanical capture and reassess the patient’s condition. Use analgesia and sedation for pain control, and try to identify the cause of the bradyarrhythmia. If transcutaneous pacing is ineffective (eg, inconsistent capture), prepare for transvenous pacing and consider obtaining expert consultation. Alternative Drugs to Consider These drugs are not first-line agents for treatment of symptomatic bradycardia. They may be considered when the bradycardia is unresponsive to atropine and as temporizing measures while awaiting the availability of a pacemaker. To simplify the algorithm, we have listed epinephrine and dopamine as alternative drugs to consider (Class IIb); they are widely available and familiar to ACLS clinicians. In this section we also summarize evidence in support of other drugs that may be considered. Epinephrine Epinephrine infusion may be used for patients with symptomatic bradycardia or hypotension after atropine or pacing fails (Class IIb). Begin the infusion at 2 to 10 g/min and titrate to patient response. Assess intravascular volume and support as needed. Dopamine Dopamine hydrochloride has both - and -adrenergic actions. Dopamine infusion (at rates of 2 to 10 g/kg per minute) can be added to epinephrine or administered alone. Titrate the dose to patient response. Assess intravascular volume and support as needed. Glucagon One case series (LOE 5)10 documented improvement in heart rate, symptoms, and signs associated with bradycardia when IV glucagon (3 mg initially, followed by infusion at 3 mg/h if necessary) was given to in-hospital patients with druginduced (eg, -blocker or calcium channel blocker overdose) symptomatic bradycardia not responding to atropine. Tachycardia This section summarizes the management of a wide variety of tachyarrhythmias. Following the overview of tachyarrhythmias and summary of the initial evaluation and treatment of tachycardia, common antiarrhythmic drugs used in the treatment of tachycardia are presented. Classification of Tachyarrhythmias The tachycardias can be classified in several ways based on the appearance of the QRS complex. Professionals at the ACLS level should be able to recognize and differentiate between sinus tachycardia, narrow-complex supraventricular tachycardia (SVT), and wide-complex tachycardia. Because ACLS providers may be unable to distinguish between supraventricular and ventricular rhythms, they should be aware that most wide-complex (broad-complex) tachycardias are ventricular in origin. • Narrow–QRS-complex (SVT) tachycardias (QRS 0.12 second) in order of frequency — Sinus tachycardia — Atrial fibrillation — Atrial flutter — AV nodal reentry — Accessory pathway–mediated tachycardia — Atrial tachycardia (ectopic and reentrant) — Multifocal atrial tachycardia (MAT) — Junctional tachycardia • Wide–QRS-complex tachycardias (QRS 0.12 second) — Ventricular tachycardia (VT) — SVT with aberrancy — Pre-excited tachycardias (advanced recognition rhythms using an accessory pathway) Irregular narrow-complex tachycardias are probably atrial fibrillation or possibly atrial flutter or MAT. The management of atrial fibrillation and flutter is discussed in the section “Irregular Tachycardias,” below. Initial Evaluation and Treatment of Tachyarrhythmias The evaluation and management of tachyarrhythmias is depicted in the ACLS Tachycardia Algorithm (Figure 2). Box numbers in the text refer to numbered boxes in this algorithm. Note that the “screened” boxes (boxes with text that is noticeably lighter, ie, Boxes 9, 10, 11, 13, and 14) indicate therapies that are intended for in-hospital use or with expert consultation available. This algorithm summarizes the management of the tachycardic patient with pulses (Box 1). If pulseless arrest develops at any time, see the ACLS Pulseless Arrest Algorithm in Part 7.2: “Management of Cardiac Arrest.” Part 7.3: Management of Symptomatic Bradycardia and Tachycardia IV-69
lV-70 Circulation December 13, 2005 wIth Pulses Assess and support ABCs as needed ve oxyg Monitor ECG (identity rhythm). blood pressure, oximetry Identify and treat reversible cause synchronized cardioversion Establish IV access and give Obtain 12-lead E Unstable signs include altered mental status, ongoing chest pain. is conscious: do not delay Is ORS narrow(c0. 12 sec)? Note: rate-related symptoms Consider expert consultation uncommon if heart rate <1 50/min see Pulseless Arrest Algorith NARROW ORS: Is Rhythm Regular? Expert consultation Give adenosine 6 mg rapid Ⅳpush. if no conversion give 12 mg rapid IV push: possible atrial flutter or MAT If atrial fibrillation with may repeat 12 mg dose once cal aberrancy Control rate (eg, dil ncertain rhythm Amiodarone Complex Ta arrow See Irregular t B-blockers: use B-biockers w 150 mo I over 10 mun or l 22 expert consultation r ele fibrillation (AF.WPw carryover Avoid AV nodal If sVT with aberrancy If rhythm does NOT convert, Give adeno probable reentry SVT possible atrial flutter. (go to Bo 7) mics(eg, amiodarone Terrene Control rate fog, Treat recurrence with B-blockers: use p-biookers with adenosine or longer caution in pulmonary disease consuitation acting AV nodal blockno i torsades de poin Consider expert consultation ad with 1-2 g over 5-60 min, then intusion) te: If patient be able, go to Box 4. Hydrogen ion (acidosis)-Tension pneumothorax Figure 2. ACLS Tachycardia Algorithm. The provider must assess the patient while supporting the tachycardia(Box 3). If the a s chest iate synchronized car tient demonstrates rate-related irway and breathing, administering oxygen(Box 2), obtain- cardiovascular compromise, ns and symptoms such ing an ECG to identify the rhythm, and monitoring blood altered mental status, ongoing chest pain, hypotension, or pressure and oxyhemoglobin saturation. The provider should other signs of shock, provide immediate synchronized car- establish IV access when possible and identify and treat diversion(Box 4--see below ) Serious signs and symptom reversible causes of the tachycardia. are uncommon if the ventricular rate is <150 beats per If signs and symptoms persist despite provision of supple minute in patients with a healthy heart. Patients with impaired mentary oxygen and support of airway and provider should determine if the patient is signs of cardiovascular compromise are unstable a on, the cardiac function or significant comorbid conditions may and if become symptomatic at lower heart rates. If the patient is unstable with narrow-complex reentry SVT, you may admin-
The provider must assess the patient while supporting the airway and breathing, administering oxygen (Box 2), obtaining an ECG to identify the rhythm, and monitoring blood pressure and oxyhemoglobin saturation. The provider should establish IV access when possible and identify and treat reversible causes of the tachycardia. If signs and symptoms persist despite provision of supplementary oxygen and support of airway and ventilation, the provider should determine if the patient is unstable and if signs of cardiovascular compromise are related to the tachycardia (Box 3). If the patient demonstrates rate-related cardiovascular compromise, with signs and symptoms such as altered mental status, ongoing chest pain, hypotension, or other signs of shock, provide immediate synchronized cardioversion (Box 4—see below). Serious signs and symptoms are uncommon if the ventricular rate is 150 beats per minute in patients with a healthy heart. Patients with impaired cardiac function or significant comorbid conditions may become symptomatic at lower heart rates. If the patient is unstable with narrow-complex reentry SVT, you may adminFigure 2. ACLS Tachycardia Algorithm. IV-70 Circulation December 13, 2005