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 mon￾itoring following cardiac transplantation. It will likely be ineffective because the transplanted heart lacks vagal inner￾vation. 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 symptom￾atic bradycardias. It should be started immediately for pa￾tients 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 cardio￾vascular symptoms are not caused by the bradycardia, the patient may not improve despite effective pacing. Transcutaneous pacing is noninvasive and can be per￾formed by ECC providers at the bedside. Initiate transcuta￾neous 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 re￾assess 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 obtain￾ing expert consultation. Alternative Drugs to Consider These drugs are not first-line agents for treatment of symp￾tomatic 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 symp￾tomatic 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 ac￾tions. 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 drug￾induced (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 manage￾ment 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 tachy￾cardic 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